ELEC590 Smart Grids

ELEC 590 Directed Study Course

Renewable Energy in Smart Grid Systems

Supervisor and instructor: Prof. Dr. Aaron Gulliver

Summer term 2014

Author: Abdullah Rehan

E-‐mail: [email protected]

1 ELEC 590 Smart Grids in Renewable Energy Technology

Acknowledgement This work has been made possible by the endless efforts and guidance of my supervisor Prof. Dr. Aaron Gulliver, Department of Electrical Engineering at University of Victoria, BC, Canada. I am thankful for his support, motivation and assistance starting from the proposal development,

continuing till the completion of the report.

Abstract

Background: The main motivation of this project is the level of greenhouse gases that has increased drastically over a period of time merely because of using conventional sources of power. Burning coal and natural gas to fulfill our energy requirements is a practice which if continued will have irreversible negative impacts on the environment. Smart grid technology is a modern system that administers the efficient delivery and management of power which when integrated with renewable energy systems can be a solution.

Objective: The main objective is to evaluate the feasibility of all renewable energy resources available so that a way to integrate them with smart grid technology can be more efficient, feasible and reliable.

Methodology: The working principle and construction procedure of each type of renewable energy and smart grid technology is studied. Then the financial and power feasibility for all renewable energy technologies and smart grid technology is analyzed.

Results: After comparing values and statistics of all renewable energy and smart grid projects, the most feasible renewable energy is figured out. A model system integrating smart grid technology and renewable energy technologies is proposed.

Conclusion: Smart grid system costs generally remain the same regardless of which renewable energy technology is integrated, but the costs are predicted to decline in the future with better technology. The cheapest renewable energy systems are wind and solar power systems. If enough capital is available, the most energy efficient and feasible systems are geothermal and biomass power stations in the long run.


Table of Contents

Chapter 1: Introduction ............................................................................................................................... 3

Chapter 2: Smart grid technology ................................................................................................................ 5

Chapter 3: Renewable energy technologies ................................................................................................ 8

3.1 Solar power ....................................................................................................................................... 10

3.1a Construction of a photovoltaic system ....................................................................................... 12

3.1b Solar fuel cells ............................................................................................................................. 13

3.2 Wind power ...................................................................................................................................... 14

3.2a Construction of a wind farm ....................................................................................................... 16

3.3 Biomass power .................................................................................................................................. 18

3.3a Construction of a biomass power plant ...................................................................................... 19

3.4 Hydroelectric power ......................................................................................................................... 21

3.4a Construction of a hydroelectricity power plant .......................................................................... 22

3.5 Emerging renewable energy technologies ........................................................................................ 23

3.5a Geothermal energy ..................................................................................................................... 23

3.5b Ocean wave energy .................................................................................................................... 24

3.5c Tidal wave energy ....................................................................................................................... 26

3.5d Innovative renewable energy technologies ................................................................................ 26

Chapter 4: Feasibility study on renewable energy .................................................................................... 28

Chapter 5: Designing a smart grid system ................................................................................................. 30

Chapter 6: Conclusion and discussion ....................................................................................................... 32

6.1 Feasibility of renewable energy technologies ............................................................................. 34

6.2 Future of integrated smart grid technology with renewable energy .......................................... 36

6.3 An ideal system integrating smart grid and renewable energy technology ................................ 36

Chapter 7: References ................................................................................................................................ 39


Chapter 1 Introduction:

The world is currently dependant on an energy infrastructure that heavily relies on fossil fuels which

have high chances of getting depleted. Such energy resources are major contributors of green house

gases and carbon dioxide. If current practices of energy generation are continued, excessive Carbon

dioxide emissions will degrade the environment. Carbon emission rates need to be maintained at

present levels by implementing carbon neutral energy resources immediately in a cost efficient manner.

Optimized energy systems with minimal production, transmission and maintenance costs are required

which provide constant energy with minimal losses. There is a huge scope for learning more about the

technicalities of how solar energy can be utilized by photovoltaic systems and solar fuel cells in addition

to biomass, wind, and other types of renewable energy resources for meeting clean energy

requirements.

Table 1: Effects of carbon economy on the environment

Source: Nathan S. Lewis and Daniel G. Nocera, “Powering the planet: Chemical challenges in solar energy utilization”, PNAS

vol.103 no.43, pages 15729-‐15735, October 24, 2006.


According to consumption rates, 50-‐150 years of oil reserves, 207-‐590 years of natural gas and 1000-‐

2000 years of coal is left to be used as energy resources which can account to up to 25-‐30TW of energy

consumption rate worldwide for centuries to come. A more hazardous issue than depletion is the rate of

emissions by using fossil fuels as energy resources. In the next 50 years, the energy consumption rate is

expected to increase to 27.6 TW from 13.5TW which will account to an increase in carbon emission rate

to 13.5 billion metric tons GtC/yr from 6.6 billion metric tons GtC/yr. These carbon emissions tend to

accumulate between the ocean surface and the atmosphere. The mixing time between the near surface

and deep oceans varies between 400-‐ thousands of years which means that until severe intervention is

done to remove these emissions actively, these gases will stay in surplus to the new emissions. Hence,

the CO2 in the atmosphere should now be limited to 550ppm and for that entirely carbon-‐neutral

energy resources are required immediately because if the process of this shift from a “high carbon

economy” to a “low carbon economy” is even delayed by 20 years, carbon neutral power equal to the

amount of power produced by all the energy resources existing combined will be required to maintain

the level of 550ppm of CO2 in the atmosphere. [1]

It is time to reform the environment-‐degrading energy infrastructure into a sustainable and resilient

energy infrastructure that is more environmental friendly. One of the main problems that the energy

sector faces is the renewable energy transportation costs over long distances when compared to the

more conventional energy coming from resources such as the fossil fuels. Another issue that arises

when analyzing the feasibility of renewable energy production is with the generation process. Since the

primary source of such energy is nature itself, the output is not constant and the fluctuation makes it an

unstable resource of energy. An ideal solution to these particular problems would be the one that

incorporates maximum use of renewable energy resources mitigating the affects of fluctuation in its

production by the use of smart grid systems (further explained in Chapter 2).


In the modern age of today, proposals and models need to be set up in order to solve the two

bottleneck energy investment problems of transmission and fluctuation of renewable energy

development during the planning phase. These long-‐term investment planning models will be an aid for

analysts, investors and policy makers for finding out methods to make extensive use of current and

emerging renewable energy technologies in order to support the development and enhancement of

renewable energy so that the world’s energy infrastructure can be transformed into a much cleaner

system over a period of perhaps the next 40 years.

Chapter 2 Smart grid technology:

Figure 1: General layout of smart grid systems

Image source: http://www.powergenasia.com/conference/smartmeter.html.

“Smart grid” nowadays is considered as a general term that refers to a type of technology that people

use to transform utility electricity systems that are used for delivery into modern 21st century delivery

systems with the help of computer-‐based remote control and automation. These particular systems can

be made incorporated today by two way communication systems and technology along with the regular


computer processing practices that have been used for many years in various industries. In the most

recent years, they are beginning to be used on electricity networks, from the different power plants and

wind farms all the way to the customers and consumers of the electricity for commercial, domestic and

industrial purposes. Such systems are able to offer numerous benefits to utilities and consumers mostly

in terms of higher efficiency and improvements in delivery of the electricity grid for energy users’ homes

and offices. The general idea of such a system can be seen in figure 1.

The invention of such systems has changed the nature of work that the workers of utility companies

have to do as well. For almost a century now, workers of the utility companies have had to go out and

gather much of the data needed to provide and regulate electricity. In order to do this, the workers have

to read meters, search for broken equipment and measure voltage which only covers a fraction what

they have had to do every day. Most of the devices that the utility companies use to deliver electricity

efficiently were not automated and computerized but because of the smart grid technology, many

options and products are now being made available to this industry to help modernize the electricity

generation process.

The conventional “grid” is basically the network that carries electricity from the plants where it is

generated to consumers that have a demand for it. This grid consists of wires, substations, transformers,

switches and a lot more.

Exactly like the way that a “smart” phone nowadays merely means a phone that has a computer in it, a

smart grid means the electric utility grid that has now been computerized and can entirely be controlled

by a computer system. One of the main tasks associated with it is adding a two-‐way digital

communication technology to all the devices that are associated with the grid and its functionality. The

devices are responsible for carrying out the same function designated to them as before but the means


of collecting that information for the relative functionality is now through the use of sensors. Devices on

the network now use sensors in order to gather data from power meters, voltage sensors and fault

detectors. The whole process is made possible by a two-‐way digital communication between the devices

in the field and the utility’s network operations center from where everything is administered and

controlled. One key feature that justifies the use of smart grid systems is the automation technology

that now lets the utility adjust and control each individual device and millions of devices from one

central location now matter how remote that is.

As inferred from principal characteristics, smart grid systems are able to use digital technology in order

to improve reliability, resiliency, flexibility, and efficiency both in terms of economy and energy of the

electric delivery system. The advantages and additional options offered by smart grid systems can be

analyzed from figure 2.

Figure 2: Importance of smart grid systems and smart meter benefits

Image source: Wave 3 – SGCC consumer pulse and segmentation research. Base=Total consumers, n=1089.


Chapter 3: Renewable energy technologies

Renewable energy is basically the energy that is generated from resources, which are naturally

replenished. These resources include sunlight, wind, rain, tides, waves and geothermal heat. By using

these renewable energy resources for energy generation, we fulfill multiple needs of the 21st century:

• Electricity generation

• Hot water/ space heating

• Fuels for motors

• Rural off-‐grid or remote areas energy services

Renewable energy is an important technology sector in the world of today because of the numerous

benefits it has to offer. The key environmental benefit attained is through the cleanliness of renewable

energy technologies because of the use of clean and green sources of energy which have a very minimal

impact on the environment. Since one is not dependant on conventional sources such as fossil fuels,

renewable energy resources will not run out and this type of energy will stay in the world for future

generations to come. Such technology is also economically feasible in the way that it creates jobs and

helps the economy. Most renewable energy investments are known to be used up on materials and

workmanship in order to construct and sustain the facilities, in contrast to costly energy imports. These

investments are mostly spent within the country of origin, often in the same state and town. This means

that the energy dollars stay at home creating employment opportunities while fueling local economies.

Meanwhile, the renewable energy technologies which are developed by each country can also be sold

overseas, in turn providing a boost to the country’s trade deficit.

Almost about 16% of the global final energy needs today are met from renewable resources, in which

10% [2] of the energy is generated from traditional biomass, (main use is for heating) and 3.4%


from hydroelectricity. New renewable energy resources such as small hydro, modern biomass, wind,

solar, geothermal, bio-‐fuels and other emerging technologies are responsible for another 3% which are

growing rapidly [3].At country level, at least 30 countries all over the world already have a renewable

energy contribution of more than 20% of the total energy supply. The exact figures of renewable energy

contribution to the total world energy consumption can be seen in figure 3.

Figure 3: Renewable energy share of total energy consumption 2010

Image source: Renewables 2011, global status report.


3.1: Solar power

Figure 4: Solar photovoltaic total world capacity


The solar cell is an integral part of the PV system and its operation is based on the fact of a direct

conversion of the electromagnetic radiation from the sun which is received mainly consisting of the

visible light of the wavelength (400 nanometers to 750 nanometers) into the usable electricity with the

help of the photovoltaic effect. This photovoltaic effect is usually composed of the conversion of energy

from the incident photons that come into electrical potential energy that is transferred to charge

carriers inside a semiconductor material, which enables them to transfer in between the different

voltage bands within the material which effectively results in the accumulation of voltage between the

two electrodes that in turn represents the output voltage of the solar cell. The total capacity of solar

photovoltaic systems can be seen in figure 4.


Various types of solar cells now exist in the market which can be integrated into photovoltaic systems

depending on their efficiency and cost. Multi-‐junction solar cells contain several p-‐n junctions and one of

each junction is tuned to a wavelength of light that is different from each other so that light is wasted.

By increasing the number of junctions, higher efficiency can be achieved but with three junctions an

efficiency of about 43% can be achieved. In contrast to the multi-‐junction solar cells, single junction

solar cells are only made up of a single p-‐n junction and have a lower efficiency of about 30%. These

cells are usually 175um thick and have dimensions of 7cm by 7cm are normally weldable and solderable.

Crystalline silicon solar cells are the kind widely available and up till now the most efficient solar cells

that provide stable power. These cells have a practical efficiency of 22.5% and are the most frequent

options when designing a PV system.

The output of PV system depends on the fill factor of a solar cell. The higher the fill factor, higher the

efficiency of the solar cell. These relationships can be seen from numeric calculations below:

These relationships can be seen from equations 1 and 2.

𝐹𝐹 = !!" × !!"!!" × !!"

….(1)

ƞ = !!"×!!" ×!! !!"

….(2)

where 𝐹𝐹 is the fill factor, 𝐼!" is the current at maximum point, 𝑉!" is the voltage at maximum point, 𝐼!" is short

circuit current, 𝑉!" is open circuit voltage, ƞ is the efficiency and 𝑃!" is the input power. PV systems are capable

of producing 1000kWh/kWpeak of energy per nominal power with 20-‐30 years of proven durability with

output that can be DC or high quality AC via an inverter. Such systems are easily scalable for less than

1W to greater than 10MW of power. The maintenance costs are generally very low until hit by

hazardous storms making these systems cost marginal. With 10% efficiency and $300/m^2 along with

balanced maintenance cost of $3/W, an optimal electricity price of $0.35 kW/hr can be achieved which


can be considered when comparing to the cost of $0.02-‐0.05 kW/hr for fossil fuels generated energies

[4].

The energy from solar power can be easily stored if inexpensive batteries become available which have

lifetimes of about 30 years. An alternative to this approach can be pumping water uphill through a

turbine powered by solar power and storing the energy mechanically but till now, a feasible system that

does not require charge and discharge every 24hours is unavailable. A third method of storing this

energy is by using an artificial photosynthesis procedure to produce a solar fuel cell in which chemical

bonds are broken and then formed.

PV power is that it is time sensitive. On a sunny day, the output power will be great but at night time, a

cloudy day or winter season when the sun is only out for a few hours, the use of PV-‐systems as source of

energy is not suggested. PV systems are also temperature sensitive since a rise in temperature accounts

to a fall in the solar cell performance; hence these systems are inefficient in extremely hot conditions.

The environmental impact of PV power is almost negligible. Crystalline solar cells make use of Cadium

which is a carcinogen and not disposable in a recycling program. PV systems are easily funded by banks

worldwide since it is the most developed form of renewable energy that exists.

3.1a) Construction of a Utility PV system

A PV system consists of a solar module, voltage converter/charge controller, a storage unit and an

inverter that converts AC into DC. The output might be connected directly to a load or to a power grid. A

solar panel consists of series and parallel connected solar cells. Typically, the cells in one panel should

match well otherwise a big difference reduces the overall efficiency and even destroys the weakest cell.

Group cells are sometimes connected in parallel so that reverse current does not become an issue

because of shadowing of a high number of cells. A solar generator will then finally have PV modules


connected in series and parallel. Each module should be regulated actively and connected in series.

Conversion of input power to output power can be done by choosing between linear regulators, buck,

buck-‐boost, boost and fly-‐back converters. Each converter has a different power input to output ratio

and efficiency so the choice depends on each application. The storage of this power generated can be

done by using big loads of lead acid accumulators or by storing the power directly into a grid where it

can be shared from with other users immediately after generation.

For an ideal PV system, the ambient temperatures need to be lower and surveys need to be done before

the area is selected so that it is made sure that the site receives a favorable amount of sun. A practical

example of a large scale PV system can consist of 150 KVA, 98.9% efficient, 208 to 480 air cooled

transformer. The ground surface preparation can be set +/+ one inch vertical in 10 feet horizontal.

About 250 MCM of copper can installed on ground for protection from lightening equipment. A high

efficiency PV module can be set at 300 feet north-‐south by 140 feet east west on ground. The wiring

design has to be for around 0.5% drop of maximum voltage from the furthest point in the array to the

inverter. By smartly designing the system, the installation costs of such power systems can be reduced

down to $0.30 per DC watt of PV capacity. Crystalline solar cells are usually used because of a stable

performance. The capacity of such a system can generally be up to 495 MW with a renewable energy of

861,143 MWh with expected values of $30.85/MWh of energy.

3.1b) Solar Fuel Cells

In one hour, 4.1*10^20 J of energy strikes the earth which is much greater than the 4.1*10^20 J of

energy that the planet uses in one year [1]. This energy is stored by an innovative process called artificial

photosynthesis. During this process, water reduction and oxidation catalysts are combined with a light

collection and charge separation system ultimately capturing spatially separated electron hole pairs to


make bonds of hydrogen and oxygen. This hydrogen is then combined with Carbon dioxide in the

atmosphere to produce solar fuels which can store the sun’s energy for later use as a renewable

resource of energy. This process can be performed by a solar fuel cell in which hydrogen and oxygen are

combined to generate an electron and proton flow through a membrane. Light is used to run the

electron and proton flow in reverse and the coupling of electrons and protons to photo catalysts

(Titanium dioxide doped with small amounts of iron or chromium [5]) breaks the bonds of water and

produces Hydrogen at the cathode and oxygen at the anode, effecting solar fuel production. This

process between the cathode and the anode results in a flow of electric current. A schematic diagram of

a solar fuel cell can be seen in figure 4.

Figure 4: Working principle of a solar fuel cell

Image Source: Nathan S. Lewis and Daniel G. Nocera, “Powering the planet: Chemical challenges in solar energy utilization”,

PNAS vol.103 no.43, pages 15729-‐15735, October 24, 2006.

3.2 Wind power The main operating principle lies in the fact of converting the wind energy into a useful form of energy

known as the electrical energy. We use wind turbines to make electrical power, windmills for the

mechanical power and wind pumps for water pumping or drainage. Wind generators have a capacity of

500-‐2000 kW with larger units having a capacity of up to 5000kW or more in off shore areas. Such

systems have high capital costs because of expensive equipment and also a very large maintenance cost

since the generators are complicated to fix, once undergone defects. The operating costs for wind

power generators tend to be low though [4].


Typical wind generating power systems are capable of an output of 2000 kWh/kWpeak with scalability

problems for systems with output under 50kW. This power is proportional to a third power of wind

speed which is not as good as the power from PV. Power from wind generators is AC and is of variable

frequency. The theoretical maximum efficiency of such systems is about 59% although conversion

efficiency comes at a price. In order for this to be a primary renewable energy resource, the price per

kWh needs to be minimized. Practical efficiencies of modern wind generators vary from 25-‐30% in

contrast to the traditional wind mill’s 5% [4]. This is a very effective form of energy because it produces

no green house gases and uses very little land. Ideally wind generators should have a large diameter and

should be installed in places with high wind speeds and high probability of wind. Their height should be

as much as possible and the temperature of the surroundings should be lower since the density of wind

decreases in such conditions. The numerical relationship between the power and these factors is shown

in equation 3.

𝑃𝑜𝑤𝑒𝑟 = !!×𝜌×𝐷!×𝑣! …..(3)

Where 𝜌 is density (Kg/𝑚!), 𝐷 is diameter (m), 𝑣 is velocity (m/s).

A typical drawback of this technology lies in the faulty gear box of a wind generator. Fast torque changes

cause untypical compression of the gearbox in the axis direction, reducing the lifetime of wind

generators to 7 from the projected number of 15 years. This typical problem is a major topic under

research now. Environmentally, wind generators shed ice in the winter, cause shadowing and noise and

also spoil the pristine looks of the countryside. The exact figures of global wind power capacity and its

growth can be seen in figure 5 and 6.


Figure 5: Wind power capacity 2011


Figure 6: Wind power capacity growth by country Image source: Renewables 2011, global status report.

3.2a) Construction of a Wind farm

Constructing and planning the development of a wind farm requires the successful completion of

several steps listed below.

1) Municipal consultations in which the residents and community of the area around the potential

wind farm are taken into dialogue and kept in constant contact throughout the process.

2) Wind assessment in which engineers and experts use meteorological masts to measure wind

speed and climatic conditions so that an estimation of energy potential can be calculated.


3) Wind farm design in which engineers are able to model wind flow, turbine performance, sound

levels, design access roads, turbine foundations, local electric network, and connection to the

electricity or smart grid.

4) Environmental study in which assessments mitigate the negative environmental impacts on the

surroundings.

5) Land acquisition in which developers negotiate terms in order to use the land.

6) Permitting and public consultation in which federal requirements and permissions are sought.

7) Economic and financial analysis in which the economic viability of the project is demonstrated.

8) Manufacturing of the wind turbine parts.

9) Site preparation and construction.

10) Commissioning in which the electrical collection network is installed and connected to the

regular or smart grid system.

11) Operation and maintenance

The tower construction is done not only regarding the weight of the nacelle and rotor blades, but also

with regard to the absorption of large static loads which are caused by the different power of the wind.

Examples of tower heights:

• hub height 40-‐65 m: approx. 600rated power and approx. 40 to 65 m rotor diameter

• hub height 65 to 114approx. 1.5 to 2rated power and approx. 70 m rotor diameter

• hub height: 120 to 130approx. 4.5 to 6rated power and approx. 112 to 126 m rotor diameter


Figure 7: Working principle of a wind turbine Image source: “Wind Energy”, EcoPlanetEnergy Renewable Energy Resources, http://www.ecoplanetenergy.com/all-‐about-‐eco-‐

energy/overview/wind/.

For wind turbines with higher power, doubly-‐fed asynchronous generators are the ideal choice. The

operating rotation speed can be changed, unlike when using the more conventional asynchronous

generators. Another option could be using the synchronous generators. A connection to the smart grid

system of synchronous generators is only made possible with the help of transformers, because of the

behavior of fixed rotation. The control system is complicated but it is offset by the overall efficiency and

better grid compatibility.

3.3 Biomass power

By using thermal and chemical conversion processes, biomass can be converted into bio fuels and other

forms used as a resource of renewable energy. Biomass is usually used for the production of power

and/or heat, and a part of it is transformed into liquid bio-‐fuel which is used for transportation. The

technologies that are used for generating electricity from biomass include direct firing or co-‐firing (with


coal or natural gas) of solid biomass, municipal organic waste, bio-‐gas, and liquid bio-‐fuels. Typical

sources of bio-‐mass energy are ethanol, pulp and residues of paper industry, wood and forest residues.

The global production of ethanol and biodiesel can be analyzed from the plots below in figure 8.

Figure 8: Production of ethanol and biodiesel Image source: Renewables 2011, global status report.

3.3a) Construction of a Biomass Power plant Biomass energy is generated by a properly defined method hence outlining a general map of a biomass

power plant. Typically when constructing a biomass power plant, a few process and sections need to be

defined:

• Fuel feeding systems

• Combustion technology

• Boiler systems

• Plant control

A biomass power plant will only be efficiently put to use if there is mechanism of constant supply of fuel.

After a thorough analysis of the available fuel by looking at its moisture content, grain size and specific


density is it decided which feeding system is to be used. Typically, underfeed stoker, multiple shaft

screws, flap-‐gate locks, hydraulic fuel feed and pneumatic blow in equipment are a few choices. The

next step is to decide on which combustion technology is to be used because this determines efficiency

and effectiveness of the plant, its performance and longevity, its emission levels and profitability. The

efficiency of the combustion system is determined by the fine-‐tuning of combustion chamber by

designing its outer surfaces (cool or uncool), optimized position of the fuel feeding system and burning

gate, the delivery and regulation of the combustion air and safe an regular removal of ash. The options

of combustion methods are usually in feed grate combustion, ring burner, under-‐freed and blow in

combustion. Boiler systems are application specific. Various types of boiler systems using water, steam

or thermal oil as the heat transfer medium are usually the options. Control and error analysis of the

power plant is done with the help of field devices that can be placed throughout the plant for the

execution of command functions, taking measurements and reporting on conditions. There are also

cabinet devices which are integrated in a central electric control box for receiving measurement

information, making and processing system queries and sending out commands [6].

Figure 9: Biomass power plant Image source: http://www.lambion.de/en/biomasse-‐kraftwerke/anlagenbau/waermeverteilung-‐kwk.html.


3.4 Hydroelectric power Hydroelectricity is a form of renewable energy that generates electricity from hydropower. It uses the

principle of the gravitational force of the falling or flowing water. It accounts for almost 16% of the

global Generation processes and it’s also expected to increase by 3.1 % each year for the next 25 years

[3]. Hydropower is converted into electricity by different ways and some include:

• Conventional hydroelectric systems in hydroelectricity dams

• Run of the river hydroelectricity that uses the kinetic energy of the rivers and streams

• Small hydro projects having no artificial reservoirs (Typical output is 10 MW)

• Micro hydro projects supply electricity to homes, villages or isolated industries

• Conduit hydroelectricity projects which use the water that has already been directed for use

elsewhere

• Pumped storage hydroelectricity that stores water pumped in times of low demand in order to

be used for power purposes when the demand is high

All the projects of generating electricity mentioned above follow a simple mathematical formula of

which states the amount of power available from falling water and this relationship can be described by

the equation:

𝑃 = ƞρ𝑄𝑔h P is the power in watts ƞ is the efficiency of the turbine ρ is the density of water in kilograms per cubic meter Q is the flow in cubic meters per second g is the acceleration due to gravity h is the height difference between inlet and outlet


3.4a) Construction of a hydroelectric power plant

Figure 10: Hydroelectric power plant and a wind turbine Image source: http://en.wikipedia.org/wiki/File:Hydroelectric_dam.svg

Image source: http://ga.water.usgs.gov/edu/graphics/hydroturbine.jpg

The typical layout of a hydroelectric dam and a wind turbine can be seen in figure 10. The main

components of a hydro electricity power plant are:

• Area • Dam • Reservoir • Penstock • Storage tank • Turbines and generator • Switchgear and protection

The area chosen to build the power plant has sufficient and unimpeded flow of water with suitable

topography to build a dam. The main function of the dam is to control the flow of water in a way that it

can be reserved for power purposes in the reservoir. The reservoir saves the water for the turbines to

generate electricity of it. The penstock is a pipe that connects the dam and turning blade and its main


job is to increase the kinetic energy of the water by maintaining a high pressure. A storage tank is only

used in an emergency situation when the pressure of water is lower and it is directly connected to the

penstock. After this, the water falls onto the turbines which convert kinetic energy of the water into

mechanical energy which is converted into electrical energy with the help of the generator. The control

equipment of the power plant includes circuits, instrumentation for warning, control devices connecting

to the main board. After the generation of electricity at low voltage, a step up transformer is used to

provide a voltage of 132KV, 220KV and 400KV as per requirement.

3.5: Emerging renewable energy technologies

3.5a) Geo-‐thermal energy

Figure 11: Geothermal power plant Image source: http://www.geothermie.de/

The Geothermal energy is generated and stored in the earth. Geothermal energy originates from the

formation of the planet itself and from the radioactive decay of the minerals and works by the principle

of the geothermal gradient. In flash geothermal conversion process, higher temperature geothermal

sources (>180°C) are used. Because of the pressure difference between the subsurface environment and


the Earth’s surface, water exists as a liquid at higher temperatures. The water with high temperature

and pressure is brought to surface, entering a low pressure chamber ultimately flashing into steam. The

pressure created by the steam channels through a turbine, spinning to generate electrical power. Also,

when a liquid is heated into a vapor, the pressure drives a turbine. When temperatures are too low for

‘flash’ water in a binary system, the heat of water needs to be transferred to a separate liquid having a

lower boiling temperature called the ‘working fluid’. When hot geothermal water comes up to surface

from deep underground, it runs through a ‘heat exchanger’ transferring the heat from the geothermal

water to the liquid working fluid. Because this working fluid has low boiling point, it vaporizes rapidly

with less geothermal heat, and the vaporization in turn produces enough pressure to drive a turbine.

3.5b) Ocean wave energy

Ocean wave is used as a resource of renewable energy when the energy transported by ocean surface

waves is captured for generating electricity. There are several modern methods that are used for

converting this energy into electricity mainly named as:

• Point absorber buoy

• Surface attenuator

• Oscillating water column

• Overtopping device

When using point absorber buoys, the device floats on the surface of the ocean attached to cables

which keep it in place by a connection to the seabed. These buoys mainly make use of the rise and fall of

swells for driving hydraulic pumps in order to generate electricity. The surface attenuator acts in a

similar fashion to point absorber buoys, but it has multiple floating segments which are connected to

each other oriented perpendicularly to incoming waves. The swells then create a flexing motion that


drives hydraulic pumps in turn generating electricity. The oscillating water column devices can be either

be located on shore or in deeper waters offshore with an air chamber incorporated into the device in

which the swells compress air in the chambers ultimately forcing air through an air turbine to generate

electricity. Overtopping devices are longer and use wave velocity to fill a reservoir to a higher water

level when compared to the surrounding ocean. The potential energy in the reservoir height is then

captured with low-‐head turbines. These devices can be either on shore or floating offshore.

Figure 12: Idea of ocean wave energy Image source: http://www.seabased.com/


3.5c) Tidal energy

Tidal power is a type of hydropower in which the energy from the tides is converted into power that is

used for generating electricity and other useful forms. This is an important form of renewable energy

because tides are more predictable and provide a more stable resource of energy, currently at a high

cost because of limited choices of sites that offer high tidal ranges and flow velocities, tidal energy is

expected to be more readily available as this technology matures with time. There a number of

methods to generate tidal power:

• Tidal stream generator • Tidal Barrage • Dynamic tidal power • Tidal lagoon

In a tidal stream generator, the kinetic energy of the tides is used to power a turbine which generates

electricity. The tidal barrage uses the potential energy in the difference of height between high tides and

low tides. The potential energy is stored by the use of specialized dams and then converted to

mechanical energy which is then turned into electrical power with the help of generators. Dynamic tidal

power, a relatively new method is still untested and is based upon the idea of using interaction between

kinetic and potential energies of tidal flows. A tidal lagoon consists of circular walls that are embedded

with turbines which capture the potential energy of tides and convert it into electrical power. The only

difference between this system and tidal barrages is the absence of an already existing ecosystem.

3.5d) Innovative renewable energy technologies

Tidal energy can be divided into two main techniques; generating energy from tidal stream and tidal

range. Tidal stream uses fast flowing tidal currents generally found in constrained channels. Tidal range

uses high and low tides found in estuarine areas. In energy generated from marine biomass, we use

micro-‐algae cultures to produce bio fuels.


Figure 13: Working principle of Reverse Electro Dialysis

Image source: “Reverse Electrodialysis technology”, REAPower, http://www.reapower.eu/project-‐scope/reverse-‐electrodyalisis-‐technology.html

Salinity gradient energy can be produced by Reverse Electro Dialysis (RED) and Pressure Retarded

Osmosis (PRO). The processes can be seen in figure 13 and figure 14 respectively. In RED, fresh water

and saline water is kept separate using a selective ion membrane in the presence of alternating cathode

and anode exchange membranes.

Figure 14: Working principle of Pressure Retarded Osmosis

Image source: http://newenergyandfuel.com/http:/newenergyandfuel/com/2008/12/05/osmotic-‐energy-‐potential/ .

The chemical potential difference between the salt and fresh and water then generates a voltage over

each membrane and the system has a total potential equal to the sum of all the potentials. PRO has a


similar working principle but in this case the difference between water potential of fresh water and salt

water corresponds to a pressure of 26 bars which is equivalent to a hydraulic head 270 meters high and

electricity is produced from it [7]. The Geothermal energy is also a form of renewable energy resource in

which electricity is generated and stored in the earth. Geothermal energy originates from the formation

of the planet itself and from the radioactive decay of the minerals and works by the principle of the

geothermal gradient.

Chapter 4: Feasibility study on renewable energy technologies

Power Plant Type

Nominal Capacity

kW

Overnight Capital Cost

($/kW)

Fixed O&M Cost

($/kW) Plant Life

Construction Time (Years)

Fuel Cost Per

MWH Capacity Factor

Advanced PC Single Unit* Coal 650,000 $3,167 $35.97 40 4 2.44 80% Conventional

NGCC* Natural Gas 540,000 $978 $14.39 30 3 3 55%

Dual Unit Nuclear

Uranium

2,236,000 $5,335 $88.75 60 7 3.00 94%

Biomass CC* Biomass

20,000 $7,894 $338.7

9 30 4 0 80%

Biomass BFB* Biomass

50,000 $3,860 $100.5

0 30 4 0 80% Onshore Wind Wind 100,000 $2,000 $28.07 20 1 0 30% Offshore Wind Wind 400,000 $4,500 $53.33 20 1 0 40% Solar Thermal Solar 100,000 $2,500 $64.00 25 1 0 25%

Small Photovoltaic Solar 7,000 $2,500 $26.04 25 1 0 15%

Large Photovoltaic Solar 150,000 $1,600 $16.70 25 1 0 17% Geothermal – Dual Flash

Geothermal 50,000 $5,578 $84.27 40 4 0 80%

Geothermal – Binary

Geothermal 50,000 $4,141 $84.27 40 4 0 80%

Hydro-‐electric Hydro 500,000 $3,076 $13.44 80 4 0 50% Pumped Storage Hydro 250,000 $5,595 $13.03 80 4 0 60%

Table 2: Characteristics of power plants [17]

• Advanced PC single unit stands for Pulverized coal power plant.


• NGCC stands for National Gas Combined Cycle plant

• Biomass CC stands for Combined Cycle plant

• BFB stands for Bubbling Fluidized Bed

The values recorded suggest that wind power stations normally have the ability to supply the highest

nominal capacity available followed by hydro power stations. In terms of nominal capacity, geothermal

stations are the least feasible option because of the way the technology operates. The overnight capital

costs depict that Biomass power stations are the most expensive to build followed by geothermal power

stations. The cheapest overnight capital costs make large photovoltaic systems the most feasible option.

Overnight capital costs are usually just a factor of comparison since this cost does not include any

possible interest rates and money value. The operation and maintenance costs follow a trend that is

very similar to the overnight capital costs. Biomass and geothermal power stations have the highest

operation and maintenance costs whereas solar and hydro power stations have the least. This cost plays

a great role in the decision making process of selecting which renewable energy technology might be

the most feasible option. Hydro and geo thermal power stations are recorded to have the highest plant

life whereas solar and wind power stations have the lowest plant life.

The plant life of a power station normally does not play a huge part in the feasibility of a renewable

energy technology unless there is a drastic difference to its counterpart’s because usually the typical

energy costs and operation and maintenance costs are able to offset this value. Photovoltaic and wind

power plants are the fastest to construct when compared to other construction times. This is a huge

advantage because associated project costs are kept to a minimum as well. When compared to

conventional power plants, all renewable energy power plants provide the advantage of having no fuel

costs based on the working principle which becomes the main reason of a shift from conventional to

renewable sources of energy. The capacity factor values suggest that biomass and geothermal power


stations are the most feasible options because solar and wind power stations provide a very low value.

The reason or this is the resource that is being used. Wind and solar power can vary greatly from initial

predictions but biomass and geothermal resources remain rather constant. This is a very important

factor in the decision making process as it shows the actual operating capacity of a power plant as

opposed to its predicted or theoretical counterpart.

Chapter 5: Designing a smart grid system

The main purpose of installing smart grid projects is to manage, monitor and control the generation,

transmission and distribution of electrical energy. These systems are able to distribute power generation

from renewable sources of energy and maximize profits from asset utilization and an efficient

management system. Driving forces of developing smart grid projects all over the world include

reliability and improved power quality, asset management, renewable energy, customer satisfaction,

energy efficiency, and emissions reduction. Smart grid projects are best suited for provinces that have

economic importance and have a high electricity demand for example industrialized cities with a

customer base consisting of households, businesses, industries, hotels and offices.

A large scale project can be divided into three stages. The first stage (approx. 4 years) usually consists of

planning and launching a pilot project. During the phase, conceptual designs are improved and

implemented followed by feasibility studies to create pilot projects for demonstration. The second stage

(approx. 4 years) is composed of large scale expansion. During this phase, renewable energy systems are

developed and upgraded and the old equipment is moved to other areas for possible usage. The new

systems are implemented and connected for smooth transition and operation of the new smart grid

technology. The third stage (approximately 4 years) is power quality and service efficiency


improvement. During the phase, a large scale expansion to cover all the areas in the plan is carried out

in order to ensure the optimization of service efficiency.

Equipment required for the completion of the project [8]:

• Installation of the Smart meter 116,308 Sets

• Installation of the Energy Storage System 2 Units

• Installation of the Mobile Workforce 1 Unit

• Installation of the Solar Rooftop 3 Units

• Installation of the Substation Automation 3 Stations

• Installation of the IT Integration System 1 System

• Installation of the Electric Vehicle Charging Station

- Quick charging 3 Units

- Normal charging 3 Units

- For EV 1 Unit

• Procurement of the electric vehicle 3 units

- EV Car 2 Units

- EV Bus 1 Unit


Figure 14: Smart grid project

Image source: http://www.fujitsu.com/global/Images/outlook-‐img01_tcm100-‐916953.jpg

5.1 Outcomes of integrating renewable energy and smart grid systems

The cost of meter reading, connecting and disconnecting is reduced. Since there is electricity’s

transgression, reduced non technical Loss, low cost of current coil, loss of voltage coil and reduced non

technical loss, there is reduced loss of revenue. The investment requirements of additional electrical

capacity are also significantly lower since the overall system’s peak load is reduced. The power would be

sold more readily and there would be lower outage costs since the reason and fault for electricity failure

can be immediately spotted with the help of the new system. This way there is also reduced cost of

operation and maintenance.


Because of such projects, installations will get a better insight into how the energy storage and testing

strategies can be improved along with providing opportunities for supplying other services such as the

energy information services. Since the new system is more automated and easily accessible, customers

will be able to keep track of their electricity usage by themselves in order to help them economize and

also enabling the state departments of electricity to introduce systems such as prepaid metering.

Project location Operational Since Comments

Enel, Italy 2008 378,000 energy customers are

catered for. [9]

Pecan Street Inc. Austin, Texas 2003 Caters 1 million consumers and

43000 businesses. [10]

Xcel Energy, Boulder, Colorado 2008 Installed 23,000 smart electric

meters. [11]

Hydro One, Ontario 2008 Serves more than 1.3 million

customers. [12]

Model city of Mannheim 2012 Uses Broadband Power Lines.

[13]

Adelaide, Australia -‐ 7000 electricity smart meters.

[14]

Evora, Portugal 2010 Supports an entire world

heritage site. [15]

Amsterdam smart city 2012 -‐ 2013 10,000 inhabitants of

Amsterdam are supported. [16]

Table 4: Current smart grid projects


Chapter 6: Conclusion and discussion

6.1 Feasibility of renewable energy technologies

Table 3: Typical energy costs

Image source: http://www.ren21.net/Portals/0/documents/Resources/GSR2011_FINAL.pdf


Analyzing the data from both the table 2 in chapter 4 it can be seen that renewable energy power plants

offer the advantage of having no fuel costs. The most viable renewable energy technologies include

solar and wind power since they do not require a lot of capital and there is enough research and

technology that already exists to provide a ready source of technology in association with smart grids.

According to the values recorded as per North America, Biomass and geothermal power plants have the

highest capacity factor which independently would make them the most feasible choices. Photovoltaic

power plants have the least capacity factor. On the contrary to the capacity factor values, photovoltaic

and hydroelectric power plants have the lowest operation and maintenance costs and with biomass

power plants having the highest costs. Since biomass, geothermal and hydroelectric power plants have

complicated and large equipment involved, the construction time for them is about the same and about

4 times longer than that of photovoltaic and wind farms. The overnight capital costs are recorded to be

the highest for geothermal and hydroelectric stations whereas they are the lowest for photovoltaic

power plants. Drawing a conclusion from these feasibility figures, wind and solar power stations will be

the cheapest and fastest options as renewable energy resources. If enough capital was available,

geothermal and hydro power stations would be the ideal solutions.

As it can be seen from table 3 above, biomass and geothermal power plants provide excellent power

capacity and hence would be the most efficient ones if connected with a smart grid. Since the initial

capital required for these power plants is very high and relatively less related technology is available,

these resources can only be used if economies are strong enough and can spare the capital to erect

biomass and geothermal power plants. If that is the case, the power capacity produced would be

significantly higher and the power plants used in collaboration with the smart grids would last much

longer. This can be proven by the typical energy costs in table 3. The energy costs for geothermal and


biomass power are recorded to be the least while for solar and wind power they are recorded to be the

highest.

6.2 Future of integrated smart grid technology with renewable energy

The installation of smart grid systems is a perfect solution to the world energy crisis. The new system is

efficient, automated, more reliable and most of all, capable of integrating all renewable energy

resources together. Since such projects improve the prospect of these resources to be used more

efficiently, the energy costs of each renewable resource are likely to decrease as well. For example, the

solar energy costs are predicted to decrease to 6-‐25c/kWh from 25-‐125 c/kWh, biomass costs are likely

to decrease to 4-‐10 c/kWh from 5-‐15 c/kWh. Similarly, wind energy costs are likely to come down to 3-‐

10 c/kWh from 5-‐13 c/kWh with geothermal energy costs reducing to 2-‐8 c/kWh from 2-‐10 c/kWh.

These systems are likely to become more main-‐stream in the near future as the investment trends

suggest. In 2010, 211 billion dollars was the global investment in renewable energy which shows a 32%

growth from the investment in the previous year. Wind power showed a growth of investment of 30%,

solar power showed a growth of 52% and geothermal a growth of 44% in just one year with Europe and

North America taking the lead.

6.3 An ideal system integrating smart grid and renewable energy technology

The working principle of smart grid technology can be seen in chapter 2. Now that the technology is

receiving more attention, the number of applications that can be used on the smart grid after the data

communications technology is instilled and deployed is increasing with growth as fast as inventive

companies are capable of creating and producing them. The advantages of using the smart grid

technology includes improved cyber-‐security and handling sources of electricity coming from wind, solar

power, biomass, hydro and other forms of renewable energy. The companies and corporations that are


making smart grid technology offering the services mentioned above include long term technology

giants, established communication firms and even fresh technology firms. Due to the incorporation of

smart gird technology into the electricity network, we have several things to gain out of it and some of

them are listed below:

• Self-‐recovery from events causing power hindrance

• Enabling active participation by consumers in demand response

• Resilience of operation against physical and cyber attacks

• Delivering improved power quality to meet the needs of 21st century

• Introducing and accommodating numerous generation and storage options

• Mitigating the effects of power fluctuation of various renewable energy resources

• Combining the output and renewable and nonrenewable resources of energy

• Enabling new products, services, and markets

• Optimizing assets and operating efficiently

The construction requirements and procedure of each type of renewable energy power station can be

seen in chapter 3. Solar power in combination with all the other forms of renewable energy that exist

today can result in feasible energy systems. Integration of major renewable energy resources through

the use of smart grid systems utilizes the topography of earth efficiently and cuts transmission costs and

losses of electricity. Such systems can compose of PV systems in areas where sun is abundant,

hydroelectric power in areas that can support dams, wind power in regions where the wind speed and

probability is high, geothermal and biomass power where the resources are enough to operate and

maintain the technology. Chapter 5 describes and explains a model system that integrates renewable

energy technologies and smart grid system together successfully. As it can be seen from table 4 in


chapter 5, this technology has already been implemented in certain parts of the world. This table also

highlights who leads the current projects.


Chapter 7: References

[1] Nathan S. Lewis and Daniel G. Nocera, “Powering the planet: Chemical challenges in solar energy utilization”, PNAS vol.103

no.43, pages 15729-‐15735, October 24, 2006.

[2] IEA publications, “World energy outlook 2006”, Chapter 15 energy for cooking in developing countries, 2006.

[3] REN21 publications, “Renewables 2011 Global Status Report”, 2011.

[4] Prof. Dr. Werner Bergholz, “Expansions from PV systems in 2 dimensions”, Lectures Energy Systems, Jacobs University

Bremen, Fall 2012.

[5] Akira Fujishima, Tata N. Rao, Donald A. Tryk, “Titanium dioxide photocatalysis”, Journal of Photochemistry and

Photobiology C: Photochemistry Reviews, Volume 1, Issue 1, 29 June 2000, Pages 1-‐21.

[6] Lambion energy solutions, “Energy from Biomass”, http://www.lambion.de/en/biomass-‐plants/bio-‐residue-‐technology.html,

retrieved on June 7th 2014.

[7] Statkraft, “OsmoticPower”,http://www.statkraft.com/energy-‐sources/osmotic-‐power/default.aspx, retrieved on 28th Nov

2013.

[8] Power gen-‐Asia, “Smart grid project”, http://www.powergenasia.com/conference/smartmeter.html, retrieved on June 8th

2014

[9] Enel, “Smart cities in Italy”, http://www.enel.com/en-‐GB/innovation/smart_grids/smart_cities/italy/, retrieved on 14th June

2014.

[10] "Building for the future: Interview with Andres Carvallo, CIO — Austin Energy Utility". Next Generation Power and Energy

(GDS Publishing Ltd....) (244). Retrieved 2008-‐11-‐26.

[11] Betsy Loeff (March 2008). "AMI Anatomy: Core Technologies in Advanced Metering". Ultrimetrics Newsletter (Automatic

Meter Reading Association (Utilimetrics)).

[12] Betsy Loeff, Demanding standards: Hydro One aims to leverage AMI via interoperability, PennWell Corporation


[13] "E-‐Energy Project Model City Mannheim". MVV Energie. 2011. Retrieved May 16, 2014.

[14] “Solar city Adelaide”, http://www.sgiclearinghouse.org/Oceania?q=node/2571&lb=1, retrieved on 14th June 2014.

[15] “Evora Smart City”, http://www.inovcity.pt/pt/Pages/homepage.aspx, retrieved on 14th June 2014.

[16] “Amsterdam Smart City”, http://amsterdamsmartcity.com/, retrieved on 15th June 2014.

[16] “US Energy Information Administration”, http://www.eia.gov/, retrieved on 16th June 2014.

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