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CHAPTER ONE
Introduction
1.0 Evaluation of Renewable Energy Options
The Draft of this Project Report summarises the desk and field study investigations on the
renewable energy potential in Kenya being part of the “Renewable Energy Sources” (RES)
Project. Emphasis is laid on the assessment of the renewable energy options with regard to
their suitability in Kenya. In this context the major tasks are:
1. Identification and localisation of renewable energy potential in Kenya;
2. Matching of the identified rural demand with the supply options on a geographical data
basis and proposal of the best-suited supply solutions (technology options);
3. Draft system design and recommendations for implementation.
In accordance with the ToR of the RES Project, the following resources are considered: Solar
energy, wind energy, small hydropower and bio-energy. Although the potential for geo-
thermal power plants is evident, this resource is not investigated because its exploitation re-
quires large-scale projects, which are beyond the context. This applies also to medium and
large-scale hydropower schemes. In addition, no pilot stage technologies (e.g. wave or sea
current energy) are taken into account as options for the RES.
The identification of the potential is entirely based on evaluation of available documentation
and compilation of existing data from different national and international investigations and
sources, supplemented by information gathered during field tours. Considering the overall
framework of the RES Project, it is obvious that the degree of detail and the accuracy of
countrywide and general assessments can only increase significantly after the ongoing iden-
tification of “rural electrification clusters/projects” leading to a more accurate investigation
for the corresponding sites. The scope of work in the field of renewable energies does not in-
clude own on-site measurements or detailed site research.
However, the following NOT own on-site missions have been included, in order to evaluate
the experience with existing projects and to gather exemplary information on certain
resources:
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• Existing community pico hydro power schemes of Kithamba and Thima (Kirinyaga
District, Central Province);
• Several pico and mini-hydro power project sites under construction or design (Kirinyaga
District in Central Province, Bureti and Kericho Districts in Rift Valley Province and
Siaya District in Nyanza Province);
• Private-operated small hydropower stations at James Finlay tea & flower farm in Kericho
District and Tenwek Hospital in Bomet District (Rift Valley Province);
• Ngong Hills wind power site (Kajiado District, Rift Valley Province);
• 10 kW biogas plant on a banana plantation at Kamahuha Market Services Centre (near
Makuyu, Murang’a District, Central Province), using banana leaves and stems as feed-
stock;
• Sisal waste use for biogas-based electricity generation at Kilifi Plantations Ltd (KPL) in
Kilifi District (Coast Province) and replication options at a sisal farm/factory at
Athine/Mogotio (Nakuru Koibatek Districts, Rift Valley Province);
• Waste use options at several flower farms around Lake Naivasha and at Molo (Nakuru
District, Rift Valley Province), and near Nyahururu (Laikipia District, Rift Valley
Province);
• Options of pineapple processing waste for biogas generation at Del Monte factory in Thi-
ka District (Central Province) and of vegetable processing waste for biogas generation at
Njoro Canning Factory (Nakuru District);
• Options of municipal waste collection for biogas generation at Homa Bay (Nyanza Prov.);
• Cogeneration options for power and heat based on rise husks at Dominion Farms (Siaya
District, Nyanza Province);
• Jatropha pilot plantation for bio-fuel generation in Malindi District (Coast Province) and
options for a large plantation with processing facilities at Dominion Farms (Siaya District,
Nyanza Province).
It should be also mentioned that private companies (farms and agro-processing industries)
were rather reluctant in providing figures on their production and that they often did not even
know the amount of waste they produce.
The first mission of the International Renewable Energy Expert to Kenya in conjunction with
MoE was carried out from 7-18 May 2007, in order to identify and evaluate existing
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information, earlier studies and investigations in the relevant fields and to develop the strategy
for the following assessments. The second mission took place from 29 October to 16
November 2007, focusing on quantification, localisation and mapping of the identified
resources. The third mission was done from 3-17 June 2008, mainly dealing with assessments
of already compiled information in the fields of hydropower, wind and bio-energy.
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CHAPTER TWO
2. Solar Energy
2.1 Current Situation of Solar Energy Utilisation in Kenya
Kenya is well known for a large-scale market-driven penetration of very small photovoltaic
(PV) systems in rural areas. It is estimated that about 200,000 rural households already use
PV systems, and that the figure is growing by about 20,000 users p.a. The PV systems have a
typically capacity of 12-50 W consisting of low-cost amorphous modules and car batteries. In
most cases, the components are bought one after the other, so that they are not well matched
to each other and often are not very reliable or long lasting. Nevertheless, due to
comparatively low costs, the use of PV in rural households is much more widespread in
Kenya than in other African countries though some of them have special PV household
electrification programs.
The application of PV systems for infrastructure and business uses focuses particularly on
telecommunication, protection of pipelines, water pumping, and small commercial or non-
commercial establishments. Also in most of these cases, the installation was initiated by the
companies, owners or organisations as an individual investment decision.
Under the Rural Electrification Programme, MoE has launched a programme for educational
and health institutions in arid and semi-arid areas (for more details, see Appendix A). MoE
commenced the programme of installing solar electricity to secondary boarding schools in
North Eastern Province in Financial Year (FY) 2005/06. During that period, 16 schools were
installed with solar electricity in Wajir, Mandera, Garissa and Ijara Districts at a cost of KSh
51,262,682. A second contract at a cost of KSh 113,491,102 was also awarded in that same
financial year to install PV systems in 21 schools in Laikipia, Kitui, Moyale, Marsabit, Isiolo
and Turkana Districts. Installation in 15 schools is completed. The remaining installation in 6
schools will be completed soon. A third contract was awarded in Financial Year 2007/08 to
carry out installation in 25 schools in Laikipia, Marakwet, Taita Taveta, Tana River, Tharaka
and West Pokot Districts at a cost of KSh 101,714,637. So far installation is complete in 15
schools and the rest was to be completed before the end of the financial year. Thus the
Government has so far carried out installation of solar electricity to 62 schools in 15 Districts
located mainly in the northern part of Kenya at a cost of KSh 266,468,421.
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Assessment has been carried out in a further 30 schools under this programme and installation
was to be carried out in FY 2008/09 at an estimated cost of KSh 150 million.
A separate programme on the provision of PV systems to about 100 health centres and 500
dispensaries has also been initiated and preparations are already ongoing. The financing of
this programme component started before the end of FY 2007/2008 and continuation in the
new FY 2008/2009 was included in the REA budget.
It is still under investigation how many out of a total of at least 2500 non-electrified
secondary schools and at least 500 non-electrified health facilities in Kenya would qualify for
PV electrification.
Figure 2-2: Calculated Average Figures of Daily Global Horizontal Solar Radiation in
Kenya 1985-1991
Since solar energy plays an important role for off-grid and stand-alone applications, the
proper system design (module size as well as storage capacity) is of major importance.
Therefore, the annual mean radiation is not the appropriate parameter for sizing of an isolated
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system, but rather the lowest radiation month or season, respectively, should be the basis for
system design, in order to ensure supply security.
The following map shows the proposed design radiation for system sizing in the different
regions in Kenya in Wh/m²*d based on the low radiation months. Despite having similar
shortcomings like the preceding map, especially regarding the problems to the north and south
of the equator line over a long section of several hundreds of km, it can be seen that the
design radiation in the dry areas of northern Kenya with more than 6 kWh/m²*d is approx-
imately 50% higher than in the mountainous and rainy areas of central Kenya. Considering
that the PV modules themselves have the major share in the total investment cost, this has a
significant impact on the system costs. A 1 kW photovoltaic module installed in Kirinyaga
would generate about 1500 kWh per year, whereas the same system installed at Lodwar could
generate more than 2200 kWh per year. This has a considerable impact on the system costs,
i.e. for providing the same services to any rural establishment (school, health centre or other)
the system costs in Kirinyaga would clearly exceed those in Lodwar, possibly in the order of
some 30%.
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Figure 2-3: Proposed Design Radiation [Wh/d*m²]
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2.2 Conclusions Regarding Utilisation Options for Solar PV Systems
Especially in the sparsely populated northern areas, with minimum radiation of more than 6
kWh/m²/day, PV systems seem to be the most appropriate option to satisfy the needs – as long
as the demand remains relatively low. The following graph illustrates a comparison of the
overall costs of a PV system and the conventional alternatives of diesel power generation and
grid extension. It is obvious that, the lower the total demand and the larger the distance from
the grid, the more likely PV is an economic solution.
Figure 2-4: Comparison of the Overall Costs of a Solar PV System and of Conven-
tional Alternatives (Diesel Power Supply and Grid Extension)
0
0.5
1
1.5
2
2.5
3
0 1 2 3 4 5 6 7 8 9 10
Daily consumption [kWh/d]
Supp
ly c
ost €
[kW
h] Diesel (1 €/l) Diesel (0.5 €/l) Grid 1 kmGrid 2 km PV (10 €/Wp) PV (6 €/Wp)
Note: The above graph is to be understood as an example providing a general orientation.
Any individual case, however, requires detailed cost estimates according to the local
conditions. Such considerations would be subject to the pre-feasibility investigation of
the demand centres / demand clusters still to be identified.
Especially for the supply of social, health or educational establishments, PV may play an
important role in decentralised rural electrification. But it is also recommended considering
the measures not only from the energy point of view but as part of an integrated attempt to
improve the overall service levels in rural areas. This requires close cooperation with other
relevant authorities, such as the Ministries of Health and Education.
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Concerning household electrification, it is presently not recommended to interfere with the
market development and to initiate government-driven PV electrification programs for private
households. However, government programs should be initiated aiming to help the rural
people to procure and to use the PV equipment, through technical as well as financing support,
such as:
• Rural credit schemes in accordance with the income patterns of the rural population;
• Quality standards or controls to avoid sales of low-quality equipment;
• Provision of independent information and education as well as related awareness activities
on energy equipment and services in rural areas.
Regarding further incentives, it appears worth mentioning that Uganda recently introduced a
45% subsidy (before 14%) on all solar power equipment in 2007 in order to boost the dis-
semination of solar PV systems for local and home-based off-grid supply. Despite different
experiences made in several countries with subsidising solar home systems, it is recom-
mended that this option should at least be checked regarding its suitability for Kenya.
Although there not many developing countries where PV dissemination, largely through
private channels, is as widespread and as fast as in Kenya, there are still many shortcomings
with sale and after-sale services such as provision of adequate maintenance, resulting in
suboptimal efficiency and reduced lifetime of PV systems. Improving this insufficient service
orientation will be very important for achieving positive impacts of the forthcoming second
generation of thin film or organic solar cells/panels, which already have 7% market share
worldwide and are much cheaper but only slightly more efficient.
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CHAPTER THREE
3. Wind Energy
3.1 Existing Experience with Wind Power Generation in Kenya
There is still little experience in using wind for power generation in Kenya, however, aware-
ness and interest is steadily growing. Most prominent and relatively successful projects are
two turbines (200 kW + 150 kW) operated by KenGen at Ngong Hills (north side) in Kajiado
District (Rift Valley Province) approx. 25 km to the west of Nairobi and one turbine (200 kW)
operated by KPLC in Northern Kenya at Marsabit (Eastern Province). Both examples show
rather good generation figures but have been facing technical problems due to the age of the
equipment. After 16 years of operation, the turbine at Marsabit (Windmaster HMZ 230 made
in Belgium) went out of order due to irrepairable rotor blade damage in 2004. For both sites,
re-powering with larger modern turbines is considered and it is expected that a significant
improvement of both the technical and the economic performance can be obtained. In addition,
planning and preparatory works for at least two grid-connected commercial-scale wind parks
at Ngong Hills (north and south sides) and Kinangop (Nyandarua District, Central Province)
are under way.
Local production and marketing of small wind generators has started and few pilot projects
are under consideration. However, only very few small and isolated wind generators are in
operation so far and no information with regard to their performance could be obtained.
Several hundreds of mechanical wind pumps were installed in the country, mainly along the
coast line, in Central Province, in the southern part of the Rift Valley and around Wajir in
North Eastern Province. There is an established local production of wind pumps using a
reliable design originally developed by ITDG. It should be mentioned that the pumps are
operating at lower wind speeds than the wind generators and the presence of wind pumps
does not necessarily mean that the area is also appropriate for wind power generation.
The following table gives an energy generation potential estimate of a typical 1 MW turbine
for the different wind speed zones.
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Table 3-1: Generation Potential of a Typical 1 MW Wind Turbine
Wind speed
at 50 m
measuring
height
Gross Production of a
typical modern 1 MW
turbine
(at sea level, 15°C,
shape parameter k=2)
Net production of typical
modern 1 MW turbine in
a wind park at 2000 m
a.s.l.*
Estimated available
area** with min.
wind speed
[km²]
6 m/s 1945 MWh/a 1360 MWh/a 50,000
7 m/s 2675 MWh/a 1921 MWh/a 4,500
8 m/s 3375 MWh/a 2482 MWh/a 1,500
9 m/s 4000 MWh/a 3000 MWh/a 700
10 m/s 4520 MWh/a 3453 MWh/a 10***
Notes:
* Project efficiency of 85% (park losses, availability, electrical losses)
** According to model calculations based on the wind map and excluding altitudes above
3300 m and protected areas, resulting in indicative and rather conservative estimations.
*** However, Fig. 3-4 (referring to the Marsabit area only) suggests that this area may be
considerably larger.
3.2 Conclusions Regarding Utilisation Options for Wind Power
With regard to wind energy use, the potential in Kenya can be assessed in general as low to
moderate, but specific areas have good to very good conditions. In general, the regions with
the highest wind speeds are mainly in mountainous areas, so that the promising exploitable
sites would be further limited by the non-accessibility or the lower energy density at high
altitudes.
The following regions in Kenya are considered as promising and worth further investigations:
- Aberdare Mountains (Central Province, Nyeri and Nyandarua Districts);
- Wider surroundings of Mount Kenya,the entire area between Aberdare Mountains,
Mount Kenya and Nyambeni Hills (northern districts of Central and central districts of
Eastern Province);
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- Escarpments to the Rift Valley (mainly Rift Valley Province);
- Areas around Marsabit (Northern Kenya, northern part of Eastern Province, Marsabit
District; already under consideration);
- Coastal area (Coast Province: Kwale, Mombasa, Kilifi, Tana River and Lamu Districts,
plus North Eastern Province: southern part of Ijara District; with slightly lower
potential).
Additional areas with high wind potential are, among others, Hurri Hills (Marsabit District),
Ndoto Mountains (Samburu District) and the area around Mount Kulal to the east of Loiyang-
alani (Marsabit District), all in northern Kenya. However, without any infrastructure and no or
insignificant demand, they are not expected having sufficient potential for project realisation
in the short to medium term.
The future exploitation of wind energy in Kenya is oriented towards power generation, both
decentralised and for the national grid. Within an integrated energy planning approach, the
wind power potential should also be exploited for substituting fossil fuels and developing the
energy sector in line with the national economic, social and environmental policies.
3.2.1 Grid-coupled Systems
The large majority of wind turbines world wide are operating in grid-coupled wind parks,
where they can be competitive to conventional power plants. It is expected that some sites
which are appropriate for such commercial scale (above 10 MW) grid-coupled wind parks can
be identified in the mentioned regions. The contribution of a grid-coupled wind park to rural
electrification would be only an indirect one in the sense that any additional generation
capacity in the national grid would relieve the system from the high load and enable grid
extension to additional areas. Energy potential and demand do not need to be located exactly
in the same area, but the required transmission lines and respective losses also limit the
economically acceptable distances of large wind parks from the demand areas.
In the short run the highest potential for grid-coupled wind parks is seen close to the existing
national grid in the Meru Central, Meru North and Nyandarua districts and at some special
exposed sites along the escarpment to the Rift Valley (such as Ngong Hills or along the road
towards Lake Magadi). Depending on the planned interconnection to Ethiopia, some of the
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areas in the northern part of Kenya might become of interest for large-scale wind park
projects in the medium term once a transmission line is passing the area.
Individual activities for wind park developing are ongoing at different sites in Kenya. Major
constraints for private investors are limited knowledge on the wind conditions in Kenya, the
necessity for long-term measurements and detailed feasibility studies as well as the require-
ment to negotiate power purchase agreements with power supply companies (currently only
KPLC).
Electricity sale to the national grid is now possible and MoE has published a feed-in tariff
guide for electricity generated from renewable energies in May 2008 (for more details, see
appendix five). Renewable power producers will be regulated by the legal framework for IPP,
the connectivity of a distinct project, and the detailed connection and sales conditions which,
however, are subject to negotiation.
3.2.2 Isolated Wind Power and Hybrid Systems with Wind Power Component
For rural electrification, isolated systems are more important than national grid connection.
MoE also promotes the development of wind-diesel hybrid systems for electricity generation
under the Rural Electrification Programme.
As already mentioned, due to the large and hardly predictable fluctuations in wind speed and
thus in wind power generation, the suitability of wind power for isolated systems is limited
and a properly designed back-up system is necessary. In Kenya, presently 6 isolated grids are
in operation which are supplied by diesel generators in the MW range and six further systems
are planned or under construction. At Marsabit there was already a wind turbine in operation
and its replacement/extension of the wind power capacity would be possible and
recommended. It is expected that, at least also for the systems in Lamu District, wind power
could reduce the fuel costs of the supply system. However, a suitable micro site for the in-
stallation still needs to be identified.
The possibility of wind battery systems or smaller wind-diesel hybrid systems for rural mini
grids needs to be investigated case by case once the demand centres are identified. Based on
available information, the districts of major interest are Nyandarua, Laikipia, Samburu
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(especially around Maralal), Meru Central, Meru North, Marsabit and the islands in the Indian
Ocean.
Compared to grid-coupled wind parks, being a well established and (nearly) economically
competitive technology worldwide, decentralised hybrid wind-diesel systems still face several
technical and economical constraints:
• Insufficient data on the wind regime for optimum system design (hybrid systems need
much more knowledge on the wind characteristics than grid-coupled systems);
• Lack of standardised and highly efficient power control systems;
• Limited local know-how for O+M and limited after-sales service by suppliers;
• Limited role of wind power as fuel saver only, requiring a full backup system;
• Very high planning and infrastructure costs (due to comparatively small project size);
• High capital costs, which make them less attractive relative to diesel-fired alternatives,
also for productive applications such as small-scale commercial farming;
• Lack of appropriate credit schemes and financing mechanisms;
• Lack of awareness on the site-specific economic opportunities offered by the technology.
A major challenge is to redress these barriers through introduction of innovative financing
and service mechanisms assisting both developers and consumers of wind energy.
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CHAPTER FOUR
4. Small Hydropower
4.1 Present Situation of Small Hydropower Exploitation in Kenya
Kenya has a considerable hydropower potential. Estimations vary between 3000 MW and
6000 MW, out of which roughly 700 MW is exploited so far, mainly in larger installations by
KenGen contributing about 60% to national electricity generation. There are 14 large dams in
operation. Three more plants are planned or under construction but not yet completed so far.
At least half of the overall potential originates from smaller rivers but small-scale candidate
sites (in the RES defined as having a capacity or potential below 10 MW) are often neglected
in the consideration because they may not be economical for grid integration. However, they
might serve well for the supply of villages, small businesses or farms in areas without grid
and thus could significantly contribute to rural development. There is a growing con-
sciousness of the possibilities that small hydropower might offer and several studies and
investigations have been carried out. However, so far only a few small hydro schemes have
been realised, either as part of the national grid supply or as stand-alone systems for agro-
industrial establishments or missionary facilities. Only few examples of community-based in-
stallations are known. Nevertheless, it seems that the first successful projects have stimulated
the interest of other communities. It is expected that the recent liberalisation of the Kenyan
power market will facilitate the engagement of private project developers and independent
power producers in areas presently not sufficiently served by the national grid.
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Table 4-1: Some Small Hydropower Schemes Currently Implemented in Kenya
Scheme Type Ownership Location
(River)
Installed
Capacity
Year of
Commissioning
Tana Mini-
hydro
KenGen Upper Tana 14.4 MW 1940 -1953
Ndula Mini-
hydro
KenGen Thika 2.0 MW 1924
Wanjii Mini-
hydro
KenGen Maragua 7.4 MW 1955
Gogo Mini-
hydro
KenGen Migori 2.0 MW 1952
Sagana Mini-
hydro
KenGen Upper Tana 1.5 MW 1952
Mesco Mini-
hydro
KenGen Maragua 0.38
MW
1919
Note: List is not exhaustive; see also Appendix 2 for examples of operating SHPP projects.
There is a growing consciousness and interest to use small hydro-power schemes for
rural/urban energy supply and various investigations are ongoing.
Recently, UNEP launched a new project, i.e. the “Small Hydro for Greening Tea Industry in
East Africa Project”, to help the tea industry generate electricity, initially 10 MW and later 82
MW from SHPP. Together with the “Co-generation for Africa Project” for the sugar industry,
the total budget is KSh 6.7 bill. GEF is financing the project through AfDB and other partners,
incl. E.A. Tea Trade Association and Energy, Environment and Development Network for
Africa.
The NGO Greenpower is developing some 25 community hydropower stations with installed
capacity between 40 kW and 1.8 MW, out of which one is already operating.
4.2 Potential for Small Hydropower
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Several studies on the Kenyan hydropower potential are available which focus on the large-
scale potential, on certain geographical regions and on very detailed sites or applications. The
first inventory of the larger hydro power resources was presented in the National Water
Master Plan of 1980 which estimated a potential of about 2770 MW. The National Power
Development Plan of 1987 came up with an estimation of about 1500 MW and a later
National Water Master Plan developed under the Kenyan-Japanese Cooperation, estimated
some 1400 MW for medium and large-scale hydro power plants.
The definition of small hydro power is internationally not standardised. In Kenya, the Ses-
sional Paper No 4 on Energy defines small hydro power site as sites with a potential of less 10
MW; however, in the National Power Development Plan even sites up 30 MW have not been
considered for development. The major investigations on potential small hydro power sites
were carried out in 1979 (Ewbank) and in 1982 (Finnconsult). In these studies, 11 out of 52
identified sites and 8 out of 39 identified sites were recommended for detailed investigations
by Ewbank and Finconsult, respectively. Even though the proximity to the grid may have
been a criterion for the proposal of the site, none of the further investigated sites has been
realised to serve the national supply system.
Putting emphasis on isolated systems, MoE in cooperation with ITDG and UNIDO focused
on the identification of pico hydro sites (less than 5 kW) for basic supply of rural
communities. Although the study was not exhaustive it resulted in the successful
implementation of two pico projects and created interest and awareness of other communities.
The potential from these very small installations is expected to add up to roughly 3 MW.
EATTA in cooperation UNEP/GEF investigated the possibility of using hydropower for the
supply of tea factories. After a scoping study, seven projects were selected for further pre-
feasibility investigations. With capacities between 400 kW and 4000 kW, the schemes would
also offer the possibility of supplying nearby households, small commercial centres or infra-
structures.
Recently, MoE did a screening of the existing studies and identified and investigated a numb-
er of further small hydro power sites exploiting natural waterfalls or series of consecutive
rapids. A non-exhaustive list including geographical positions was prepared by MoE but so
far no systematic mapping was made and the matter is not yet included in the ongoing elect-
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rification planning and works. Nevertheless, the RES project will take this issue under special
consideration.
The following map shows the locations of the small hydropower sites as investigated by MoE
(dots in green colour) as well as a summary compilation from various preceding older studies
(dots in red colour).
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Figure 4-1: Small Hydropower Schemes Currently Investigated and Implemented in
Kenya
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As can be seen, the potential for small hydropower sites is mainly located in the south-west of
Kenya (Lake Victoria drainage basin) as well as in areas south-west of the line Mount Kenya
– Aberdare Mountains. Thus it is concentrated in districts which have also high population
density and high energy demand. In particular for the sites taken from the older studies, the
location was difficult because of missing or wrong coordinates so that they are not yet
completely mapped.
In total, more than 260 small hydropower sites have been identified. Their estimated theoret-
ical potential amounts to more than 600 MW. About 45% of the potential is located in the
Lake Victoria Drainage basin, but the largest number of sites is found in the Tana River
drainage basin, mainly in the districts of Kirinyaga, Thika, Maragua, Meru South and Meru
Central (see Small Hydroelectric Power Resource Assessment Preliminary Report, M.
Odhiambo, MoE). It is expected that systematic research could identify further potential (low
head) sites.
The flow data were taken from different sources (older studies, hydrological department, or
expert estimates) and are not complete. Thus the figures are not fully comparable. Partly only
mean flow data and partly minimum flow are available only so that the assumptions on the
potential as well as the quantification are not completely consistent.
In addition, so far only the theoretical potential has been considered. What will be the really
exploitable potential and the capacity to be installed depends on various factors, mainly the
technical limitations and the costs to access and to exploit the identified sites. But also the
question whether a hydro scheme operates as isolated or as grid-connected system affects
very much the design and the installed capacity. In addition, conflict of use or water rights as
well as environmental considerations or legal and concession aspects, such as the 3 MW
threshold between license and permit requirements (for more details on legal and regulatory
issues regarding licenses and permits, see Annex 4), may reduce the actually exploitable
power potential at a certain site.
Such considerations are subject to more detailed investigations. Confirmation and further
investigations with regard to real system sizing and cost estimates will be carried out for those
sites located close to the identified demand clusters for rural electrification.
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CHAPTER FIVE
5. Bio-Energy
5.1 Current Situation of Biogas Utilisation in Kenya
5.1.1 Biogas
Since the 1980s nearly 1000 household size biogas digesters, mainly fed with cattle dung,
were constructed to provide gas for cooking and lighting to rural families. It is estimated that
about 30-50% of them are meanwhile out of order. The main problems were poor masonry,
site selection, operational workload, limited water supply, insufficient feedstock, high main-
tenance cost, limited technical support as well as unreliable models (e.g. floating channels
from steel getting exposed to erosion), all of which were introduced to the country by
different NGOs and GoK agencies. Presently the technology has evolved and local experience
has developed to arouse the interest of local SME some of which are working in close
linkages with foreign experts and NGOs. Recent developments have brought in assorted
designs of both small and large biogas systems targeting a diverse range of feedstock and
clientele.
The models available range from portable digesters as small as 6 m3 to large turn key projects.
Materials in use include plastic, steel, rubber, concrete and masonry. The latest entry is the
Africa Biogas Partnership Programme targeting small-scale dairy farmers and planning to
assist in the construction of several thousands of biogas digesters in the next five years.
The skills of the players are also varied. There are simple builders with basic knowledge of
how to build digesters. Others in the NGO sector identify potential areas of technology
application and employ contractors with corresponding expertise. And there are those who
have an advanced capacity to design biogas systems matching individual requirements and
having the ability to make profound decisions in material selections. They have the flexibility
in the choice of design, site, materials, and are better knowledgeable in the design of biogas-
electric systems which are beginning to attract interest in the generation of electricity.
In the 1970s, a large-scale biogas digester was installed at Ngong Farmers’ Training Centre
(FTC). At the time, the 1300 acre FTC was supporting a herd of about 700 cows. The 90 m3
digester was meant to supply cooking gas to the FTC and AHITI kitchens both within the
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FTC. In addition two electric biogas generators were installed to supply power to the com-
pound. The elaborately designed and installed biogas system failed after operating for only a
few years. There were no clear explanations available for the cause of failure since all the
people with expertise were no longer at the FTC. At MoE, there is also no information on the
operation of the system available. When visiting the plant site in January 2009, the external
parts of the digester were worn out, pumps and electrical accessories were vandalised. The
two generators and most accessories looked intact because the keys to the generator house
have been missing for a long time.
There were no further interests in large biogas plants until the end of 1980s when construction
of batteries of medium-size digesters started at few sites. In the early 1990s, the di-
versification of feedstock to include sewage from institutions was started through the
initiative of private companies and NGOs. The most notable was the 250 m3 digester system
of North Kinangop Hospital which has supplied 40% of the hospital’s cooking fuel from
sewage since 1998. Interest on large-scale biogas plants has been rising gradually and now
has shifted to large-scale plants providing gas for electricity production using various types of
wastes as feedstock such as waste from slaughterhouses, agricultural processing or municipal
waste. In 2007 two plants were commissioned: one is generating about 150 kW from a
mixture of waste from sisal processing and cow dung at KPL in Kilifi District (Coast
Province), and another 10 kW plant was installed at Kamahuha Marketing Centre in
Murang’a South District (Central Province) using banana leaves, stems and fruit waste as
feedstock (see also Appendix 3). The proliferation of SME in recent years has led to the
introduction of various biogas accessories from China including biogas engines of less than
10 kW.
5.1.2 Dual Fuel Gas-oil/Biogas Reciprocating Engines
Gas-fuelled reciprocating engines coupled to generator sets and cogeneration units for power
generation have been manufactured since the 1970s. These engines are run on various gases
such as biogas – generated from anaerobic fermentation of biological materials – and other
combustible gases from other processes such as wood gasification. Such gas engines were
installed in the Ngong biogas project in the 1970s while they are now available in the Kenyan
market through importation from China.
- 23 -
Other conventional engines can however be operated on such biogases after minor to
moderate modifications on the engines depending on whether they run on petrol or diesel.
5.1.2.1 Petrol Engines
Small petrol engines are modified to use biogas by introduction of a gas mixing device
between the air cleaner and the carburettor. The mixing device can be a Venturi mixture
designed and machined to fit the specific requirements of the engine, but also a simple tee-
pipe connection for very small engines which can be manufactured even at a modestly
equipped village workshop at a very low price.
In both situations, biogas is supplied to the engine directly from the biogas digester or the
biogas storage through a gas pipeline. The gas pressure is low and the engine suction is
usually sufficient to supply the engine with the required amount of gas.
Petrol engines can be operated – which usually is the case – by 100% supply of biogas lead-
ing too 100% saving in petrol cost of power generation. A typical 5 kW engine consumes
about 3 m3/h of biogas. Such modification is applicable in many situations where the com-
monly available stationary engines in rural environments can save on petrol.
5.1.2.2 Diesel Engines
There are two options for operating diesel engines to run on biogas.
a) Diesel/Biogas Dual Fuel
The easiest option is to operate the engine on a blend of biogas and diesel to save on the
diesel cost when biogas supply is available and to switch back to diesel when biogas is in
short supply. This means that there cannot be permanent modification on the diesel engine in
order to make the switch between diesel/biogas blend and pure diesel operations possible.
- 24 -
In the dual fuel model, there has to be a minimum amount of diesel that must flow through the
injectors for two reasons:
• To maintain the injectors in serviceable condition without risk of blockage by carbon
deposits;
• To cool the injectors.
Thus a minimum of 20% diesel must be allowed to flow while a maximum of 80% is replaced
by biogas.
b) Diesel Engine Conversion to Gas Engine
For large-scale power production in situations where a gas engine is not available, it is
possible to convert the diesel engine to run 100% on biogas. This is the more difficult option
requiring careful design considerations and, therefore, the involvement of an experienced
diesel engine workshop.
The modification includes the following:
• Replacement of the injectors by spark plugs;
• Replacement of the diesel injector pump with a suitable distributtor;
• Alteration of the completion ratio of the engine.
A practical example where this option is in use is Kilifi Plantations Ltd. Their 150 kW power
plant has two 75 kW diesel gen-sets having been modified to use 100% biogas.
5.2 General Considerations
Due to rising costs for conventional fuel, biomass is increasingly considered as alternative
fuel for energy generation and large companies (even the petroleum sector) are entering the
bio-fuel business. For high profitability, large-scale monocultures are required, causing social,
environmental and economic problems as known with other large monocultures, too.
Some negative examples for industrial scale bio-energy production (such as the destruction of
rain forest in Indonesia for copal production, the conflicts with indigenous territories for the
- 25 -
sugarcane/bio-ethanol production in Brazil, or the increasing prices for maize in Mexico due
to the energy vs. food competition) have thrown some critical light on bio-energy in general.
Whether bio-energy (energy crops) has an overall positive or negative impact is a question of
how their production is realised in detail. For sure, there is huge potential for the sustainable
development and production of different types of energy crops in Kenya, which could help
the local population to serve their energy needs and eventually to create some income for
them. However, the question to which extent production is sustainable, where and how much
of which energy crop could be cultivated, needs more detailed investigations and assessments.
For this reason, the following considerations are restricted to presently unused organic waste
from various existing agricultural or agro-industrial processes only.
5.3 Energy Potential from Organic Waste
5.3.1 Bagasse Cogeneration
The Kenyan sugar production amounts to nearly 500,000 MT per year and is still significantly
less than the country’s consumption. There are presently seven sugar factories in operation
which are all considering extension of production.
Table 5-1: Current and Planned Capacity of Sugar Factories in Kenya
Sugar Factory Current Capacity
[TCD*]
Planned Future Capacity [TCD*]
Sony 3,120 6,500
Chemelil 3,360 7,000
Muhoroni 2,200 4,000
Mumias 9,200 9,400
Nzoia 3,360 7,000
West Kenya 2,500 3,500
Soin 100 600
Total 23,840 37,900
Note: * TCD = tons of cane per day
Source: MoE, Cogeneration Report 2007
- 26 -
Most factories presently use bagasse to produce the steam required for the manufacturing
process and to generate electricity for their own needs. This means that the sugar industry is
probably the most advanced Kenyan industry with regard to exploiting its own energy resour-
ces from waste, but it is not yet using its resources fully.
Even with growing production, the Kenyan sugar industry expects economic pressure due to
high competition and decreasing prices. So the extension of cogeneration capacities and
electricity sales to the national grid is investigated as a potential second source of income.
MoE has undertaken a pre-feasibility investigation and for some factories detailed planning
studies are already ongoing. The following table summarises the estimated potential for
electricity generation.
Table 5-2: Estimated Power and Electricity Generation Potential of Sugar Factories
in Kenya
Sugar
Factory
Power Potential
[MW]
Electricity
Generation
[MWh/a]
Internal
Electricity Use
[MWh/a]
Electricity Available
for Grid Export
[MWh/a]
Sony 37 231,000 50,000 181,000
Chemelil 29 156,000 47,000 108,000
Muhoroni 19.8 134,000 27,000 108,000
Mumias 47 236,000 57,000 179,000
Nzoia 40 221,000 47,000 174,000
West Kenya 20 109,000 29,000 80,000
Soin n/a n/a n/a n/a
Total 192.8 1,087,000 257,000 830,000
Source: MoE, Pre-feasibility Report – Electricity Generation from Cane Bagasse
Mumias Sugar Co. (MSC), which already has bagasse-based co-generation and a Power
Purchase Agreement (PPA) with KPLC for grid supply of 2 MW since 2005, plans to increase
the capacity of its co-generation plant to 35 MW by November 2008 of which 26 MW will be
fed into the national grid according to a recent PPA between MSC and KPLC. The project
costs amount to 60 MUSD. For realising this plan and to further stabilise the connection to the
National Grid, MSC has just tendered a 30 km Mumias-Musaga 132 kV transmission line.
- 27 -
Apart from MSC, it is not known whether other large sugar companies such as Chemelil
(Nyando District) and Sony at Awendo (Migori District) or medium-sized ones such as
Miwani (recently acquired by MSC), Muhoroni (both Nyando District) and Nzoia (Bungoma
District) are prepared for large-scale co-generation including grid supply. It should be
mentioned in this context that the Kenyan sugar industry is not yet competitive at COMESA
(Common Market for Eastern and Southern Africa) level and requires another 3-4 year
interim period with restricted sugar import quota. As the sugar factories are all located close
to the national grid, a decentralised or off-grid supply based on co-generation is not envisaged.
The following table shows the quantities of bagasse produced by the sugar factories in 2006.
Table 5-3: Bagasse Production by Sugar Factories in Kenya, 2006
Factory Sony Chemelil Muhoroni Mumias Nzoia W.
Kenya
Total
Bagasse (t) 223,445 270,920 161,431 842,989 222,705 156,663 1,878,153
Source: Year Book of Sugar Statistics 2006
UNEP launched a new project for the sugar industry, called “Co-generation for Africa
Project”, to promote electricity generation, with initially 60 MW and later 200 MW from
bagasse. Together with the “Small Hydro for Greening Tea Industry in East Africa Project”,
the total budget is KSh 6.7 bill. GEF is financing the project through AfDB and other partners,
incl. the Energy, Environment and Development Network for Africa.
5.3.2 Biogas from Flower Farms
The Kenyan floriculture industry has been recording the highest growth in volume and value
of cut flowers exported every year. In 2006 the quantity of cut flowers amounted to 86,480 t.
(Economic Survey 2007). The floriculture sector in Kenya is the second largest foreign ex-
change earner after tea.
The main production areas are in Rift Valley Province (Kericho, Trans Nzoia, Uasin Gishu,
Nandi, Kajiado and Nakuru), Central Province (Nyandarua, Kiambu, Murang’a, Maragua and
Thika) and Eastern Province (Machakos, Meru Central and Embu). The 56 members of the
- 28 -
Kenya Flower Council are contributing about 80% to the flower export and having some 1350
ha under cultivation.
Potential for Power Generation from Floriculture Waste
So far there has not been any systematic research on the waste and the potential energy
production from the flower farms, thus, only some rough estimates can be made. It is sup-
posed that the marketable flowers constitute only some 15-20% of the totally produced bio-
mass. Assuming the same biogas production rates as the waste from gardens or parks, a daily
power generation of roughly 200 kWh per ton of waste could be expected. The total power
that could be generated from the waste of the members of the Kenya Flower Council is
estimated at 87 GWh/a, which would correspond to an installed capacity of about 20 MW
(depending on operation and design load factor).
With the concentration of flower farms in the area of Lake Naivasha, the highest potential for
energy generation is found in Nakuru District (including the newly created Naivasha District),
followed by Thika and Kiambu Districts.
Table 5-4: Energy Generation and Installed Capacity Potentials in the Kenyan
Floriculture Industry by District
District
Potential Energy Generation
[MWh/a]
Capacity
[kW]
Nakuru* 35,741 8,160
Thika 8,935 2,040
Kiambu 7,148 1,632
Kajiado 6,552 1,496
Laikipia 4,170 952
Nyandarua 4,170 952
Meru 3,574 816
Gatundu 2,383 544
Machakos 2,383 544
Nyeri 2,383 544
Trans Nzoia 2,383 544
Athi River 1,787 408
Other 7,150 1,220
Total 88,758.16 19,852
- 29 -
Note: * Including the newly created Naivasha District where most flower farms are located.
Table 5-5: Characteristics of Power Potential from Waste at Five Sample Flower
Farms (courtesy, Ministry of Energy)
Name of Flower Farm Suera Kongoni Everflora Hamwe Kundenga**
Location Nyahururu Nanyuki Juja Naivasha Molo
Size [ha] 30 15 20 20 12
Resident Staff 1200 250 450 non 140
Generators [total kW*] 700 503 486 237
Annual Power Cost [KSh mill.*] 12 6 9.2 4.8 2.7
Daily Waste Yield [t] 25 12 15 10-15 -
Power Potential from Waste
[kW]
400-500 200-250 300-350 100-160 -
* Unfortunately no load factors are available, but there are typically older generators kept at
the farms which are only used as stand-by, so that the information which could be obtained
is not sufficient to properly assess the real power needs.
** Kundenga in second year of development was using diesel generators only by the time of
visit in June 2008. The power bill represents the cost of diesel consumed in the first 5
months of 2008. At the time, the diesel price had gone up from KSh 65 (2007) to KSh 90
per litre (May 2008).
The above estimates show that the potential energy production from the flower waste is in a
similar range like the energy demand. But even if there is no excess power to be sold to the
electrical grid, the installation of biogas systems at the flower farms would relieve the
national supply systems from these loads so that the saved power would available for rural
electrification purposes.
5.3.3 Biogas from Sisal Production
Kenya is one of the largest sisal producers in the world. After the severe decline of the sisal
market in the 1960s and 1970s, in the last decade sisal, as a natural product, is becoming more
and more demanded again. Recent years have shown growing markets and production
- 30 -
increases by about 3% p.a. Present sisal production is in the range of about 26,000 t/a, out of
which more than 80% is produced by the seven large sisal estates in Kenya.
Table 5-6: Sisal Waste Production by Large Estates in Kenya (courtesy, MoE)
Sisal Company Location (District) Approximate Fibre Production [t/a]
Rea Vipingo Plantations Vipingo (Kilifi) 5,000
DWA Estate Ltd. Kibwezi (Makueni) 6,000
Taita Estate Mwatate (Taita Taveta) 7,200
Mogotio Plantations
Ltd.
Mogotio (Koibatek) 3,600
Kilifi Plantations Ltd. Kilifi 1,000 (estimated)
Tabu Estate Ltd. Kilifi 1,000 (estimated)
Voi Sisal Estate Voi (Taita Taveta) 400
In addition, there is also the gasification option which delivers CO instead of CH4.
Potential for Power Generation from Sisal Waste
The production of one ton of clean and dry fibre will produce about 19 t of waste (depending
on the production, this is diluted with about 5 tons of water from the washing). A biogas
production rate of 0.4 m³/kg VS has been observed during DTI (Danish Technology Institute)
studies. This corresponds to a typical gas yield of about 54 m³/t of waste. Using typical fig-
ures on biogas composition and engine efficiency, this would be sufficient to generate about
1750 kWh per ton of produced fibre.
- 31 -
Table 5-7: Energy Generation and Capacity Potentials in the Kenyan Sisal Industry
Company Generation Potential [MWh/a] Capacity* [kW]
Rea Vipingo Plantations 8,750 1500 – 2000
DWA Estate Ltd. 10,500 1800 – 2400
Taita Estate 12,600 2150 – 2870
Mogotio Plantations
Ltd.
6,300 1080 – 1440
Kilifi Plantations Ltd. 1,750 300 – 400
Tabu Estate Ltd. 1,750 300 – 400
Voi Sisal Estate 700 120 – 160
Note: * Assuming 12 to 16 hours full load
It should be mentioned that the production itself uses a certain share of the generated power to
run auxiliary equipment, such as stirrers, water pumps and slurry pumps.
5.3.4 Biogas from Food Processing Industry
Several food processing industries exist in Kenya. Unfortunately it is very difficult to get
reliable figures on their production as well as amount and composition of the waste they
produce. Very often they do not even know it exactly themselves.
The largest pineapple producer in Kenya is Del Monte Estate in Thika District. Del Monte
produces about 250,000 t of fresh pineapple, representing more than 60% of the country’s
production. All fruits are canned or processed to juice; the daily processing capacity of the
factory is about 1500 t.
- 32 -
According to the factory, about 3% of the fruit is wasted in the process. However, the observ-
ation of several big trucks which have been filled with waste during a visit and other factors
such as the estimated amount of daily waste production in the order of 50-100 t suggest that
the waste proportion is much higher. With such a daily waste production (50-100 t), about 25-
50 MWh of electricity could be generated.
In addition to the fruit pulp waste, a large amount of about 7,000 m³/d of waste water with a
chemical oxygen demand (COD) of more than 3,000 mg/l are produced, which is presently
treated in ponds (aerobic treatment which consumes energy for pumping and aeration). Con-
verting this into anaerobe treatment could produce biogas for the generation of another
6 MWh/d.
Although the Del Monte factory is by far the largest, nevertheless considerable further poten-
tial is expected from smaller food-processing industries, too. However, since the food indust-
ries are located close the cities and the economic centres of the country, the use of the organic
waste might play only an indirect role for rural electrification. The power which is produced
by the industry and consumed by the factories themselves is not taken from the grid and
would be available to supply rural areas.
5.3.5 Municipal Waste / Landfill Gas
Municipal waste could become a source of biogas and energy, too, as long as there is an
efficient waste and gas collection and management system established. An estimate for solid
waste generation and the potential for power production from solid waste has been prepared
for six sample municipalities. It is assumed that 60-70% of total waste generated is organic
and that about 25% of the landfill gas could be captured.
- 33 -
Table 5-8: Energy Generation and Capacity Potentials from Municipal Waste in Six
Municipalities of Western Kenya
Municipality Projected Pop-
ulation 2004
Total
Waste
(t/d)
Daily Gas
Yield
[m³]
Electricity
Generation
[kWh/d]
Capacity
[kW]
Kisumu 356,324 178 8,010 13,617 1000-1200
Kericho 107,014 54 2,430 4,131 300- 250
Kisii 72,025 36 1,620 2,754 200- 250
Homa Bay 64,319 32 1,440 2,448 190- 220
Nyamira 48,024 24 1,080 1,836 130- 160
Bungoma 155,102 40 1,800 3,060 220- 250
Source (of waste generation estimate): Feasibility Study on Solid Waste Management;
Ministry of Local Government, August 2004
It should be mentioned that the process itself will consume part of the energy. The energy
generation alone might not be the major gain of such a project, but rather the reduction of the
total amount of waste as well as the reduction of the hazard for environment and health.
Apart from electricity generation, municipal waste could be converted to energy also by
gasification or straight combustion. In the latter case co-generation would enhance efficiency.
The decision which method is more appropriate depends on various factors, such as total
amount, composition and humidity, and needs to be investigated for each case. In addition,
municipal waste use for cooling as well as supportive heat for municipal waste should also be
considered under the energy use options.
- 34 -
5.3.6 Other Sources
Wastes from slaughter houses or wastewater, e.g. from coffee and sugar factories, would also
be appropriate feedstock for biogas plants. Unfortunately, no data could be found on the
amounts of waste and the locations.
An additional option being targeted is waste use from hotels for biogas generation.
Water hyacinth may serve as a rich source for anaerobic biogas generation. But also in this
case additional further investigation and technological experience is required before it could
be considered as a realistic option for rural electrification purposes.
5.3.6.1 Cattle Farms
The majority of the large biogas plants worldwide use cattle manure as feedstock, either as the
only feedstock or for mixing with plant residues and stabilising the process. Operating a plant
with cattle dung requires indoor keeping of the animals. While zero grazing is common in the
highlands of Western Kenya, with a large number of suitable farms, it is rarely found in
ASAL areas.
Wherever large cattle ranches have centralised dung collection points, the possibility for sus-
tainable electricity generation for such ranches should be investigated thoroughly prior to
project implementation.
5.3.6.2 Wood
About 2% of Kenya is covered by forests which produce about 45% of the biomass energy.
Currently, forestry residues or waste from wood processing plants are fully used by the local
population for household energy needs, i.e. mainly cooking and heating. Promoting the use of
forest and wood residues for electricity production would surely compete with these uses and
would make the situation with regard to the already scarce resource even more difficult.
- 35 -
An invasive weed – prosopis juliflora – is spreading not only on marginal soils in arid and
semi-arid regions but also on their prime farmlands and pastures. It could offer a potentially
large – and so far unutilised – wood fuel source. However, at present it is not yet sufficiently
investigated to be considered in the RES study.
5.3.6.3 Rice Husks, Coffee Husks and Similar Agricultural Residues
Husks, coconut shells or other dry organic waste from milling, grinding etc. is partly already
used as cheap household fuel for cooking. Electricity generation from such waste is also con-
sidered and investigated, e.g. for rice husks at Dominion Farms in Siaya District, but approp-
riated biomass conversion technologies for small-scale applications need to be identified. For
instance, gasification of rice husks was already investigated, but only very little experience
exists in this field. Other non-electric energy conversion technologies in this respect could be
pelletising or briquetting. Husks might also be used as supportive fuel in the context of burn-
ing municipal waste or other wet materials.
5.4 Conclusions Regarding Bio-Energy Utilisation Options
As shown in the following map, it is evident that the biomass/biogas potential is concentrated
in the areas with the highest agricultural production, which are the south-western parts of the
country and the central (mountainous) areas with high precipitation. They are also the most
populated regions.
The exemplary investigation of some processes shows that there is a considerable potential
for energy generation from biomass/biogas in the country. However, its use for electricity
production requires the appropriate conversion technologies. The different types and sources
cannot be treated all in the same way; thus, much more research is required to quantify the
detailed potential and to identify the special technical aspects and challenges for each of the
considered sources.
The largest potential for implementation is currently believed to exist for the cogeneration
from bagasse in the sugar industry because in this case the processes are already established
for the supply of the company-internal needs, so that this is not a new technology, but rather
- 36 -
an extension of existing capacities. But location and scale of the considered projects also
indicate that this potential may not be directly exploited for rural electrification purposes. The
effect is seen rather in relieving the national grid from the present high loads.
Figure 5-1: Plantation Areas in Kenya with Biomass Potential
Source: Kenya Energy Atlas and DEPHA
Biogas from organic waste is certainly an option in the medium term, but it is also understood
that the realisation still needs a lot of investigation in order to run the biological processes in a
highly efficient way. All assessments on potential gas production have been made under the
general assumptions of using similar feedstock or based on specifications for individual
laboratory tests as reported in literature. Hardly real figures from existing plants with compar-
- 37 -
able conditions are known, so that a large uncertainty with regard to the potential generations
and therefore a high risk for the investor remains.
Concerning all mentioned biogas sources, it should be considered that biogas production for
electricity generation alone is unlikely to be economic unless sufficient raw material is freely
available on site. In the short run, however, there are several additional advantages and effects
of the anaerobic treatment, such as:
• Provision of waste heat or cooling for the production processes;
• Decrease of the total waste amount to be deposited;
• Reduced hazards for health and environment from the waste;
• Availability of improved fertiliser;
• Reduced methane release to the atmosphere (in most cases).
- 38 -
CHAPTER SIX
6. Renewable Energy Resources and Their Relevance in
Electrification
6.1 Spatial Distribution
The above investigations demonstrate that Kenya has considerable potential for the use of
renewable energy. Nevertheless, its exploitation for electrification purposes often requires a
case by case assessment and much more detailed research is required than in the case of a
simple diesel or small hydropower system. The potential for the different resources is not
equally distributed over the country; however, the different resources complement each other
so that there is at least one option for every location.
Hydropower resources are concentrated in mountainous areas with high precipitation such as
Nyanza, Western and Central Provinces as well as parts of Eastern Province. These are also
the regions with the highest population density and the highest agricultural production, and
thus biomass potential. Small hydropower as well as biogas plants would be an available
source to supply isolated grids in rural areas or to feed into the national grid if it is already
nearby. The relatively dense population in the mentioned areas could make mini-grids and
isolated grids viable.
Wind power resources are prevailing in a zone extending from south to north along the
escarpments to the Rift Valley as well as in the mountainous areas and nearby (largely desert)
plains of Northern Kenya, especially in Marsabit District. A somewhat lower potential is
found along the coast. Apart from the Greater Nairobi and adjoining Rift Valley areas, un-
fortunately most of the high wind speed areas have little infrastructure and low population
density with hardly any urban centre, so that the opportunity for isolated grids with wind-
diesel hybrid systems is limited. Due to the high dependence on the site conditions and the
difficulties to predict the fluctuating potential, profound investigations are required prior to
project realisation. This effort might be too high if only very small demands need to be met.
Solar energy could be exploited all over the country; however, the northern arid and semi-arid
areas have about 50% higher potential. Photovoltaic is a modular technology and can be
- 39 -
applied even at very small scale to supply a single user or distinct appliance. The specific
costs do not vary much with the capacity of the system so that PV systems appear appropriate
for isolated uses.
6.2 Techno-economic Considerations
The general assessment of the costs for renewable energy systems is difficult because the
investment costs and even more the energy yields depend very much on the individual
application. The following table provides only a rough summary on the typical costs and
operational characteristics of various relevant renewable energy resources in Kenya and
technologies to exploit them.
Table 6-1: Summary on Typical Costs and Operational Characteristics of Relevant
Renewable Energy Options for Electrification
Source Typical
Capacities
Specific
Cost
[€/kW]
Capacity
Factor
[h/a]
Required
Back-up
Remarks
Solar PV 20 W - 10 kW 4000 - 6000* 1400 - 2000 Battery Well suited for very
small isolated
systems
Wind 50 W - 1 kW
10 kW - 1
MW
1 - 100 MW
2500 - 5000*
1500 - 2000
900 - 1300
1000 - 4000
1500 - 4000
1500 - 4000
Battery
Diesel
Grid
Extremely sensitive
to the local condi-
tions; little experi-
ence in Kenya so far
Small
Hydro
1 kW - 20
MW
1500 - 3000 6000 - 8000 No Suited for mini grids
and for connection to
the national grid
Biogas
Biomass
200 kW-1
MW
5-100 MW
4000 - 6000
1500 - 2500
8000
8000
No
No
Limited experience
in the country
Note: * Battery costs included
- 40 -
The overview demonstrates that small hydropower schemes and grid-coupled wind parks
could have the lowest generation costs. However, large grid-coupled systems would only
indirectly contribute to rural electrification. In isolated wind or wind-hybrid systems, a second
source (back-up) is required, contributing significantly to the overall system cost.
Wherever small hydropower sites are identified close to local load centre such as a settlement,
a small-scale industry or a commercial centre, hydropower would be the first option to be
investigated in more detail. Small hydropower is a well established technology and the
construction works can be partly carried out by the local population. A properly designed
small hydropower scheme can completely supply the local demand with an isolated grid and
could later also be integrated into the national grid. There would be no competition or danger
of losing the investment in case of future grid extension. A further advantage in Kenya is the
spatial accordance of the dense population (and electricity demand) and the availability of
hydropower resources (both due to high precipitation).
Even if the latter applies also for the biomass/biogas resources, especially the biogas re-
sources are deemed to need further research and investigation until they can be efficiently
exploited. Large-scale biogas plants are not trivial to operate and the performance of the fer-
mentation units depends on several factors, whose influence is not fully known. Different
from a hydropower scheme or a diesel generator, a biogas plant needs a start-up phase of
several months until the process is in a stable steady state. During this time, further investig-
ations including variations and adjustments of operational parameters are necessary which
requires experienced operators. This applies especially if such type of material is used which
has rarely been used as feedstock before (i.e. wastewater from coffee factories, banana leaves,
etc.). As farmers or processing factories can hardly take over the risks of the processes,
professional operators for the plants are required.
From the technical point of view, solar PV would be the easiest and fastest technology to
serve immediate basic needs for electricity. Despite some fluctuations in the energy yield, it
can be applied all over Kenya without further investigation. For the supply of individual
isolated establishments, such as schools or rural health centres, social centres or similar in the
sparsely populated areas, solar PV would probably be the best option. But when it comes to
high demand or demand clusters, conventional supply might be much more economic.
- 41 -
Photovoltaic would be the option to be considered if no other resource can be brought to the
location.
Deviating from recommendations in existing studies and investigations on the renewable
energy potential, more detailed (pre-) feasibility investigations are not recommended from the
point of view of the potential, but rather under demand aspects. Only where demand clusters
with a certain ability and willingness to pay are identified, the provisionally identified
resources should be investigated in more detail in order to identify the most economic
resource to meet the demand.
6.2.1 Resource-specific Feed-in Tariffs
6.2.1.1 Small Hydropower
In the MoE document on “Feed-in-Tariffs Policy for Wind, Biomass and Small-Hydro Re-
source Generated Electricity” (March 2008), small hydropower refers to plants with an
installed capacity between 500 kW and 10 MW.
The FiT shall apply for 15 years from the date of first commissioning of the hydropower plant,
being applicable to individual small hydropower plants (SHPP) with effective capacity not ex-
ceeding 10 MW. A firm tariff shall apply to the first 100 MW capacity of hydro firm power
plants whereas a non-firm tariff shall apply to the first 50 MW capacity of hydro non-firm
power plants, i.e. being applicable to all SHPP.
A stepped fixed tariff for firm and non-firm power not exceeding the figures in the table
below shall apply on electrical energy supplied in bulk to the grid operator at the
interconnection point.
Table 6-2: Fixed Maximum Tariffs for Firm and Non-firm Power from Small Hydro-
power Plants
Effective Generation Capacity of SHPP Firm Power Tariff Non-Firm Power
Tariff
MW US¢/kWh US¢/kWh
0.5-1 12 10
1-5 10 8
5-10 8 6
- 42 -
Table 6-3: Estimated Long Run Marginal Cost for Small Hydropower Plants
Effective Generation Capacity of SHPP New SHPP Rehabilitation of SHPP
MW US¢/kWh US¢/kWh
0.5-1 12.7 3.5
1-5 11.7 3.3
5-10 10.0 2.9
Source: Own estimate of the Consultant
The feed-in tariff is in line with generation cost for new SHPP in the range of 0.5-1 MW. For
higher capacities, the feed-in tariff does not allow to cover the economic cost of new SHPP.
However, the feed-in tariff becomes quite attractive in the case of the rehabilitation of an
abandoned hydro site. Since the economic cost of SHPP generation reflects mainly the con-
struction cost, the feed-in tariff should be adjusted for each new project commissioned with-
out any impact on the SHPP already in operation. Thus, a specific 15-year supply contract
(PPA) should be signed for each SHPP.
It should be considered giving also SHPP with a capacity below 500 kW (at least down to
10 kW) the option of feeding into the grid at the tariffs in the range of 0.5-1 MW.
6.2.1.2 Wind Power
The FiT shall apply for 15 years from the date of first commissioning of the wind power plant,
being applicable to individual wind farms with effective capacity not exceeding 50 MW and
to the first 150 MW capacity of wind power plants.
The fixed tariff shall not exceed 9 US¢/kWh supplied in bulk to the grid operator at the inter-
connection point.
The above feed-in tariff is adequate wherever the wind resource enables an availability factor
of at least 40% – which is quite restrictive on the site selection. It is recommended to link the
feed-in tariff to the wind resource. This will enlarge the development potential of wind power
in Kenya avoiding wind fall profits for the most favourable sites.
- 43 -
6.2.1.3 Biomass Energy
Biomass refers to plant or animal-based energy resource including agricultural and municipal
waste, such as bagasse, as well as bio-fuels, biogas and fuel-wood.
The FiT shall apply for 15 years from the date of first commissioning of the biomass power
plant, being applicable to individual biomass power plants with effective capacity not exceed-
ing 40 MW. A firm tariff shall apply to the first 150 MW capacity of biomass power plants
whereas a non-firm tariff shall apply to the first 50 MW capacity of power plants with a bio-
mass share of less than 70% in the annual fuel consumption.
The firm power fixed tariff shall not exceed 7 US¢/kWh supplied in bulk to the grid operator
at the interconnection point while the non-firm power fixed tariff shall not exceed
4.5 US¢/kWh.
The above tariff will favour the use of biomass as a co-firing fuel with coal or heavy fuel oil.
It will also favour projects aiming at over-sizing bagasse burning power plants for producing
excess power. However this tariff is not sufficient for the development of biogas plants.
Based on investigations and discussions with independent biomass power producers, the
amounts for the firm and non-firm power fixed tariffs appear too low. For a sustainable and
cost-covering plant operation, the tariffs should be in the same order as for small hydropower
(see above) and be stepped by plant size. In addition, the tariff structure should also differ-
entiate between different types and technologies of biomass and be subject to indexation over
the 15-year period.
6.2.1.4 Summary of Renewable Energy Plant Tariffs
The following table gives a summary of the FiT structure for the types of renewable energy
generation considered in the MoE Policy Paper.
- 44 -
Table 6-4: Fixed Maximum Tariffs for Power from Renewable Energy Plants
Effective Generation Capacity Firm Power Tariff Non-Firm Power
Tariff
MW US¢/kWh US¢/kWh
1. Small Hydropower
0.5-1 12.0 10.0
1-5 10.0 8.0
5-10 8.0 6.0
2. Wind Power ≤50 9.0
3. Biomass Power ≤40 7.0 4.5
Note: For any individual capacity larger than the maximum capacity limits stated in the table,
the FiT is to be negotiated on commercial basis.
6.2.2 Recommendations
6.2.2.1 General
In general, the amounts set for the FiT in all branches of renewable power generation should
be subject to indexation over the 15-year period, because otherwise the financial risk for the
power producer is too high. In this respect, the FiT policy and tariff review every three years
is insufficient, especially since it only applies to new PPAs and contracts concluded after-
wards and does not envisage adjustments for already existing ones.
6.2.2.2 Hydropower Generation
SHPP with a capacity below 500 kW (at least down to 10 kW) should not be denied the
option of feeding into the grid and also be offered the tariffs in the range of 0.5-1 MW.
- 45 -
6.2.2.3 Biomass Energy Generation
The amounts for the firm (7 US¢/kWh) and non-firm (4.5 US¢/kWh) power fixed tariffs
appear too low. For a sustainable and cost-covering plant operation, the tariffs should be in
the same order as for small hydropower and be stepped by plant size (firm tariff: 8-12
US¢/kWh; non-firm tariff: 6-10 US¢/kWh). In addition, the tariff structure should also
differentiate between different types and technologies of biomass.
- 46 -
CHAPTER SEVEN
7. Proposals of Renewable Energy Projects and Preparatory Activities in the Field of
Electrification
7.1 Small Hydropower
The pico hydropower stations installed in Kirinyaya District have obviously aroused a lot of
community interest in such projects, clearly demonstrating the impact of successful pilot
projects.It was found out that most of the potential SHP sites in Central Province have been
acquired by the neighbouring communities with the intention of developing them in the future.
The communities have no expertise in developing such sites and depend on the private sector
for advice in the course of such development. There were cases where some community
projects were abandoned by private consultants after disagreements arose in the course of
development of some sites. In such situations, the communities were disillusioned and risked
losing already committed money either in the hands of dishonest businessmen or in installed
but still un-commissioned equipment.
It is proposed that MoE undertakes more such pilot projects, based on the SHP database, with
focus on catchment areas of the upper Tana and Athi River Basins, especially in the Mount
Kenya region, as well as in the Lake Victoria basin catchment areas. Emphasis should be
given to their adequate design and supervision, thus ensuring optimisation of the site
potentials. Distribution of power to the community homes and load control are areas requiring
close guidance by MoE in order to enhance sustainability and safety. The involvement of
MoE would also facilitate attracting external financing for such community projects.
Brief Description of the Proposed Small Hydropower Pilot Project for Local Communi-
ties
Role of MoE: Site selection, Design, Finance 50%
- 47 -
Role of Partner: Site selection, Finance 50%, documentation, operation & maintenance
Partnership: PPP (involving the local community, possibly including local administ-
rative bodies and community-based organisations/NGO)
Capacity: 500 kW
No. of plants: 4
Technology: Hydro
Estimated Costs: US$ 3.5m each, including partner contribution
Total Cost Estimate: US$ 14 mill.
7.2 Solar Photovoltaic Systems
7.2.1 Capacity Building of Entrepreneurs in Solar Systems Design
Presently the bulk of solar systems for the public are supplied by the private sector. This is a
welcome development. However there is still a large number of reported failures mostly as a
result poor system sizing.
MoE, together with the stakeholders such as KEREA, other NGOs, KEBS, UN organisations,
lead players in solar PV systems, carry out joint efforts to develop capacity of the upcoming
solar enterprises in sizing and installations of solar PV systems. This can be done through
training of the enterprises and education on the consequences of failed systems to their busi-
ness and the sub-sector. Education in proper business ethics combined with improved quality
of solar products in the market will enhance the adaptation rate of solar PV in areas remote to
the grid.
7.2.2 Projects for Adequate Maintenance of PV Systems at Schools
The micro studies conducted under the RES have encountered incidents of theft of solar
panels from school projects, e.g. in Turkana and Isiolo Districts. The Ministry in charge of the
schools (Ministry of Education, MoEd) should explore the possibility of engaging solar com-
- 48 -
panies in a tendering process to install such solar systems in a maintenance contract with the
schools. The companies shall regularly inspect these systems and report to both school and
MoEd on status and action required and by whom.
7.2.3 Solar PV outside of School Buildings in ASAL
Though it would not make economic sense to link staff houses to the school PV systems,
MoE, in cooperation with MoEd, should investigate the possibility of providing such school
staff together with nearby communities with charging centres for LED lamps powered by
solar PV. The LED lighting technology is fast spreading and beyond experimentation stage.
LED lamps are reputed as device with very low power consumption. A 1 Watt lamp would
provide far more and superior light than the traditional kerosene tin lamp. The LED lamps
have the potential to reduce the dependence on kerosene for lighting provided that a means of
recharging the lamps at least once or twice per week – depending on the quality of the battery
in the lamp – is available. A PV based charging centre can easily serve this purpose at modest
costs since no wiring is required. The LED lamps would have to be brought to the centre for
charging at a small fee for the maintenance and security of the centre. Such a centre within or
outside the school compound (e.g. a community centre, a church or mosque compound) could
be funded jointly with the community to guarantee ownership and protection since it will
benefit many more people in the community.
It is proposed to MoE piloting on such charging centres to serve communities in remote
demand centres where grid extension is not viable.
7.2.4 Brief Description of the Proposed Solar PV Pilot Project for LED Lamp
Charging
Role of MoE: Site selection of piloting demand centre, Design, Finance 50%
Role of Partner: The partner will be the community who will select the site and pro-
vide the land, finance 50%, and carry out documentation, operation
& maintenance
Partnership: PPP (involving the local community, possibly including local
administrative bodies and community-based organisations/NGO)
- 49 -
Capacity: 0.5 kW
No. of LED Lamps: 100 - 200
No. of Charging Centres: 50
Technology: Solar PV Central Charging
Estimated Costs: US$ 40,000 each, including partner contribution
Total Cost Estimate: US$ 2 mill.
7.3 Wind
7.3.1 Proposed Decentralised Wind Power Projects
7.3.1.1 Replacement of Defective Turbine for the Wind-Diesel System at Marsabit
The town of Marsabit including its surroundings is supplied by an isolated grid, powered by a
wind-diesel system, consisting of four diesel units (effective capacity: 600 kW, 600 kW, 120
kW, 220 kW standby, i.e. 1,540 kW total) and one wind turbine (200 kW). The wind turbine,
which was installed in 1988, broke down in 2004 and should be replaced. The control system
had the option to reduce the power of the wind turbine during low demand and high wind
speed periods. Unfortunately there are no recordings on the production available and no
statistics is available on reduced production. Estimations on average wind power penetration
of more then 40%, and up to 80% during high wind speed periods could be found. Although
these figures are very indicative, they demonstrate a rather good performance and underline
the excellent wind conditions at Marsabit.
The design of an optimised wind-diesel system normally requires a detailed investigation of
the wind conditions (including daily and annual variations) and of the daily and annually
demand curves. The economic optimum of the installed wind capacity will balance between
high total contributions of wind power and limitation of the unused power. It should also be
considered that the number of available small wind turbines which would fit into the system
in Marsabit is limited. The selection of the most suitable turbine type will depend on other ad-
vantages too and thus, the theoretical optimum of wind power contribution will not be
realised in practice.
- 50 -
Figure 7-1: Diurnal Variation of the Monthly Wind Speed at Marsabit in Year 2000
Based on the above figure and further information from the Wind resource atlas of Kenya, a
typical daily wind power generation has been calculated.
The daily load curve obtained from KPLC refers only to one sample day in July 2008 instead
of the annual average. At that day, the total demand was about 30% higher than the average
demand in 2006, so that additional demand information (also seasonal variations) would be of
interest. Nevertheless the curve is considered as typical and representative for Marsabit, so
that is was compared to the possible turbine generation.
- 51 -
Figure 7-2: Possible Generation of One or Two Sample Wind Turbines as against the
Daily Load Curve at Marsabit
Turbine generation versus daily load
0
100
200
300
400
500
600
700
1 3 5 7 9 11 13 15 17 19 21 23
hour
[kW
] 2 x 275 kW275kW daily demand
For the calculation, the Vergnet 275 kW turbine, which can be erected without crane, was
selected as sample turbine.
From the graph, the following information can be derived, as shown in the table below.
Table 7-1: Possible Generation and Related Data of One or Two Sample Wind Turb-
ines as against the Power Demand at Marsabit
Turbine Option
Technical and Related Data
1 x 275 kW 2 x 275 Kw
Average power demand [kWh/day] 9,790 9,790
Average used wind power [kWh/day] 4,360 7,584
Non-usable wind power [kWh/day] 14 1,163
Non-usable wind power (%) 0.3% 13.3%
Capacity factor wind turbine (%) 66% 57%
Share of wind power in the total production (%) 44.5% 77.5%
Annual reduction/savings of diesel generation [kWh/a] 1,591,400 2,768,160
Estimated investment cost incl. installation (USD) 750,000 1,400,000
- 52 -
The detailed design study should take into account proposed and already planned or ongoing
measures for the extension of the Marsabit grid system and the projected growth of the power
demand.
7.3.1.2 (Pre-) Feasibility Investigation for Wind-Diesel System at Lamu
At present the Lamu Diesel power station has a total effective capacity of about 1,920 kW.
Relocation of the power plant to Mokowe and stage-wise extension by 1-3 MW is foreseen.
The average power daily demand in 2006/2007 was reported to be 16,094 kWh. Daily load
curves could not be obtained. It may be assumed that due to climatic conditions cooling con-
tributes significantly to the overall demand, which might result in a more balanced load curve.
The situation at Lamu is different from Marsabit where the wind conditions are much better
and also much better analysed so that the positive economic effect of the wind turbine is not
in doubt. At Lamu, however, a detailed investigation is necessary to identify the best suited
micro site and to assess the overall feasibility of a hybrid system.
There are different sources for wind speed information but they are partly contradictory. The
modelled wind map as well as the ocean wind speed information system QuickSCAT provide
figures of some 6-6.5 m at 50 m height while the Meteorological Department measured 4.1
m/s at 10 m height. (The one-year measurement installed in May 2006 shows only 2.9 m/s at
10 m height, but it is assumed that this is due to inappropriate mast location and shading
through buildings) It is expected that micro sites with 6.5 m/s at 50 m hub height can be found
close to Lamu. According to the daily wind speed characteristics, the maximum speed is
during the day between 13:00 and 18:00 and the lowest wind speeds are after midnight, i.e.
during the low demand period.
The energy yield estimation for a 225 kW turbine (Vestas RRB India) and hypothetical wind
characteristics estimated on the basis of Divers Meteorological Services, shows that probably
1125 kW (5 x 225 kW) rated wind generator capacity could be fully taken up by the isolated
system.
- 53 -
Table 7-2: Possible Generation and Related Data of a Sample Wind Park as against
the Power Demand at Lamu
Wind Park Option 5 x 225 kW
Technical and Related Data Estimated Data
Average power demand [kWh/day] 16,094
Average used wind power [kWh/day] 6,120
Non-usable wind power [kWh/day] 0
Non-usable wind power (%) 0.0%
Capacity factor wind park (%) 22%
Share of wind power in the total production (%) 38%
Annual reduction of diesel generation [kWh/a] 2,233,800
Estimated investment cost incl. installation (USD) 2,475,000
The economics of such a project still need to be investigated in more detail on the basis of
more reliable wind data and better knowledge on the demand structure.
7.3.1.3 Wind-Solar Hybrid Systems
The use of small wind turbines can be promoted by setting up pilot wind-solar hybrid power
plants in remote locations where the population is too sparsely distributed for extending
distribution grids. The selection of such sites will have to be guided by the wind-solar data so
that the unavailability of one energy source can be complemented by the other. Such pilot
plants would be designed in a way that they promote small-scale local business at the selected
pilot locations.
The pilot hybrid projects would include the following business:
• Charging of portable LED lamps and torches replacing kerosene and dry cells;
• Charging of mobile phones;
• Powering of small-scale village enterprises such as hair saloons, hotels, ICT training etc.;
• Lighting of community centres, schools and/or dispensaries.
- 54 -
In preparing such pilot projects, daily wind data with related curves are required for the
selected sites which should be based on measurements, as far as possible in coordination with
the measuring programme proposed in the preceding subsection.
- 55 -
REFERENCES:
1. Edward S. Cassedy, Grossman, Introduction to Energy, Cambridge University Press,
1998
2. W. D. Stevenson, Elements of power system analysis, Mc Graw Hill, 1982
3. www.angelfire.com/mac/egmatthews/winam/windpower.html
4. www.solar-aid.org
5. www.energy.go.ke/index2.php?option=com_content&do_pdf=1&id=7
6. www.agores.org/POLICY/GLOBAL_STRATEGY/AFRICA/Kenya/Default.htm
7. www.energy.sourceguides.com/businesses/byGeo/byC/Kenya/Kenya.shtml
8. www.un.org/esa/sustdev/sdissues/energy/op/nepadkarekezi
9. Ralph Overend, Eduardo de Lorenzo, “Renewable energy world,” Overview
, vol. 3, pp. 9-93, Oct 2000
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