Smart grids and de- carbonising the power sector...1 1 Smart grids and de-carbonising the power...
20
1 1 Smart grids and de- carbonising the power sector N. Jenkins, FREng, FIEEE
Smart grids and de- carbonising the power sector...1 1 Smart grids and de-carbonising the power sector N. Jenkins, FREng, FIEEE Thank you for inviting me to give this Seminar. I intend
Thank you for inviting me to give this Seminar. I intend to talk for 30 -40 minutes and then look forward to a more interactive session. My name is Nick Jenkins and I teach at Cardiff University in the UK . Cardiff is the capital of Wales. I am here at Stanford for this quarter as the Shimizu Visiting Professor in Civil and Environmental Engineering where I am giving a class on Distributed Generation and the Grid Integration of Renewables
2
Structure of talk
• Smart Power Networks• National energy policies• 2020 targets – 35% of electrical energy
from Renewables • 2030-50 - De-carbonising the power sector• Role of Smart Networks and research
questions for the universities
Presenter
Presentation Notes
The structure of the talk is To discuss what is commonly understood by Smart Power Networks or Smart Grids. The concept has been discussed for around 5 years and it is important to understand both the ideas behind it and the progress that has been made to date on its realisation. To review the major national energy policies which are remarkably similar for many countries in their pursuit of de-carbonisation and the use of Renewables for electricity generation. Then to see how Smart Power Networks will contribute to these energy policy goals, particularly in terms of the 2020 ambitions of many countries to increase the fraction of electrical energy generated from renewables up to around 30-35%. To move on briefly to the even more demanding ambition of decarbonising the power sector – a policy ambition that is now emerging as an important driver and to consider how Smart Networks can contribute to achieving these policy ambitions while containing costs. In principle we can achieve de-carbonisation of the power sector but without Smart Networks and effective Demand Side Participation the costs will be very high. Thus a key role of research is to investigate how to reduce costs
3
G GG Power Plants
SwitchingSubstation
Sub-transmissionGrid (90/63 kV)
Transmission Grid (765/400 kV)
Distribution Grid (20 kV, 230 V)
Substation
ServiceTransformer
(380V-220V)
Networks today…
Presenter
Presentation Notes
The existing interconnected power system was developed starting from around the 1930s with the last major investment in the 70s and 80s. Large central generating plants (fossil, hydro or nuclear) produce electrical energy that is then fed up into an interconnected transmission gird and then distributed through distribution circuits to customers. There are a number of features that are being challenged by the Smart Network concept. The generators are large and the transmission network strong but in many places the transmission network is limited to a regional facility to connect large generators to loads. It does not facilitate a truly open market of electrical energy due to the presence of significant transmission constraints. There is very little involvement of the domestic customer. Electrical energy is priced as a commodity without differentiation of its costs of production, which vary significantly over time. In general electrical energy is supplied whenever requested at a uniform price. There is little role for local or micro-generation other than “behind the meter” to reduce the energy purchased from the network. At the lower “Distribution” voltages there is little use of ICT (Information and Control Technologies).
4
Development of European energy carrier networks
Annual global investments in energy systems -billion Euro 2000-
Massive investments in energy infrastructure anticipated
Significant increase in infrastructure required for an effective market
Source: IMAGE/TIMER model (EEA, 2005).European Environment Agencyhttp://reports.eea.eu.int/eea_report_2005_1Copyright EEA, Copenhagen, (2004)
Presenter
Presentation Notes
The RH Figure shows the electricity transmission flows in Europe across National Borders. These are presently quite limited as each national power system has been developed mainly in isolation with transfer capacity only being used in emergencies. This is beginning to change with cross-border energy trading but, as was shown by the Italian black-out a few years ago the extent of cross border trading is stretching the transfer capacity of the networks. It is proposed that increased interconnection will lead to a more effective market and hence reduced costs. I understand a similar situation exists in the US. The LH Figure shows the projected global annual investment (in 2000 prices) for energy systems assumed in a European study. Investment rises from EUR 600 billion/year in 2000 to EUR 2 300 billion/year by 2050. The largest investments are expected in the electricity sector (growing to EUR 1 000 billion/year) and in fossil fuels (growing to EUR 900 billion/year). Hence the question is how to spend the money (that has to be spent anyway)? Irrespective of the development of Smart Networks and the ever more challenging policy ambitions to limit climate change, major investments will be required in energy infrastructure to meet rising demand and to replace ageing assets.
5
….facing new issues….technical
e.g. congestion, ageing, technology development
….environmentaland socio-economic
Presenter
Presentation Notes
So as we know, we are facing important new issues in the electrical power sector. Technically these include: An ageing asset base with a need to replace much generation as well as transmission and distribution plant. There is limited technical capability both within the power companies and manufacturers. We do not really know what to do and do not have enough people to do it! Congestion in transmission networks is distorting the market in electrical energy and leading to economic inefficiency. New technology emerging (particularly ICT) but with no clear vision as to how to deploy it We have major socio-economic and environmental constraints in terms of: High and volatile fossil fuel prices and continuing concerns over security of fuel supplies. Demanding policy objectives for GHG reduction that seem to get more onerous on an annual basis as policy is reviewed..
6
ENVIRONMENT
Efficient and cleanertechnologies
Climate change
Emissiontrading
Primary energy sources
Reliability, Quality and Protection
Capacity
Regulation of market
Low prices and efficiency
Innovation andCompetitiveness
Drivers for innovation
Presenter
Presentation Notes
This leads to this triangle which illustrates that we are driven to innovate by concerns over Security of Energy Supply Environmental concerns particularly GHG emission reduction And an established economic orthodoxy that the way to deliver these goals in a cost effective manner is through an effective market both for energy, ancillary services and (It is hoped) infrastructure.. I think there is presently little discussion of the importance of the market in terms of power sector operation but a number of commentators are questioning if the market, particularly as presently constructed, will deliver appropriate infrastructure during this period of rapid change.
7
The concept of “Smart Power Networks”
“Smart” coexistence of central and decentralised generation with lower carbon generation and efficient demand/response
Load trading and cost optimisation by means of dialog towards time-variable tariffs and variable incentives depending on present load
Customer integration based on bi-directional communication and large flow of information
Presenter
Presentation Notes
Hence to consider what we mean by “Smart” Networks “Smart” coexistence of central and decentralised generation with lower carbon generation and efficient demand/response Note combination of central and distributed generation, important role for DSP demand Side Participation) and increased use of ICT. There is a particular aggregation problem of very large numbers of small generators Load trading and cost optimisation by means of dialog towards time-variable tariffs and variable incentives depending on present load Use of the energy market to ensure costs of generation are reflected in prices and the system operated optimally Customer integration based on bi-directional communication and large flow of information. Increased involvement of the customer and dramatically increased volume of data. There is a particular question of how to manage the very large flows of data and present useful information to customers.
8
Key opportunities of “Smart Power Networks”
Security of supply – efficient mix of centralised with decentralised operation allows the use of domestic energy resources, whilst maintaining a high level of reliability and quality of supply.
Climate change – higher efficiency in energy transport and use of RES and cleaner Distributed Generation, incl. CHP, results in a real contribution to reduce emissions.
Competitiveness of Industry – stimulate innovation of network and associated ICT represents a positive effect, worldwide.
Presenter
Presentation Notes
So what is the potential benefit? Security of supply – efficient mix of centralised with decentralised operation allows the use of domestic energy resources, whilst maintaining a high level of reliability and quality of supply. Effective integration of DG and micro-generation. It is becoming increasingly clear that we need to understand how to implement microgeneration is a cost-effective manner. Climate change – higher efficiency in energy transport and use of RES and cleaner Distributed Generation, incl. CHP, results in a real contribution to reduce emissions. There is increasing emphasis on the use of renewables and here Smart Networks have an important role for generation connected to the Distribution Network Competitiveness of Industry – stimulate innovation of network and associated ICT represents a positive effect, worldwide. Major new industrial opportunities. A fortunate coincidence of energy and industrial policy.
9
Contemporary policy context• 2020: Many countries now have
ambitions to increase the share of Renewables in electricity generation to around 35% of electrical energy.
• 2050: There appears to be an emerging consensus that cuts in GHG emissions of more than 80% are required, and that this will require the de-carbonisation of the power sector.
Presenter
Presentation Notes
So to leave Smart Networks for a moment and turn to the rapidly evolving scene of energy policy. My interpretation of this, at present, is that we have 2 key targets, which for convenience, I will refer to as “2020” and “2050” The 2020 target is to increase the share of electrical energy generated from renewables to around 35%. We can argue over the precise numbers and dates but broadly this is the ambition of most of Europe and a number of states in the USA. This is extremely ambitions and requires a great deal of detailed work. However it can be achieved and a major focus of research will be to limit the capacity of the plant we will use and hence contain costs. The 2nd ambition is to decarbonise the electric power sector and so make a major contribution to the 80% reductions in GHG emissions that are now being proposed. This is a much more demanding and uncertain ambition, particularly if we are to do this without massive amounts of generation and transmission/distribution facilities.
10
2020:UK Renewable Energy Strategy
Presenter
Presentation Notes
This shows one scenario of how we might obtain 35% of the electrical energy in the UK from Renewables. The 2006 situation is shown on the LH side, where we are when the last data was available. The RH graph shows that for 2020 we have to rely on established commercially available technologies. Hence there will be a dominant component from onshore and offshore wind with small contributions from Tidal Stream (the subject of last weeks seminar) Small Hydro Biomass Although the plant mix in the US (and California) is likely to be quite different, the message that only technologies that can be bought now on commercial terms are likely to make a material contribution is I think relevant.
11
Features of the 2020 electrical energy supply system?
• 30-35% of electrical energy from Renewables based on established technologies.
• For the UK, the dominant technology is likely to be onshore and offshore wind.
• One scenario projects 14,000 MW of onshore and 14,000 MW of offshore wind.
• Major transmission circuits traditionally take 10 years to permit and construct.
Presenter
Presentation Notes
12
Challenges for 2020 - Generation• Increased plant margin and
hence reduced running hours (and therefore profitability?) for some generation
• Considerable use of flexible and probably less efficient thermal plant
• Smart Networks: increase demand side participation though Smart Metering
Presenter
Presentation Notes
So the implication for the generation system are significantly increased capacities of generation and hence plant margins. (Generation plant margin is simply the fraction of generation constructed that is in excess of peak load) This will lead to reduced running hours for some generators and hence either very high electricity prices during these running hours or reduced profitability of those generators. There is likely to be considerable use of fossil fired peaking plant (combustion turbines) with a low thermal efficiency and high emissions. The role of smart networks is to dramatically increase Demand Side Participation in order to manipulate the load and reduce it at times of low generation and high demand. This manipulation of the load can be either by direct control or by sending variable price signals to which it is hoped the customer will respond. One of the considerable uncertainties is the extent to which electricity demand is elastic with price under various circumstances and how customers will respond to price signals.
13
National Grid 2020 “Gone Green” scenario http://www.nationalgrid.com/NR/rdonlyres
Presenter
Presentation Notes
This shows one particular scenario from the National Grid Company, the transmission operator of the GB network as it considers the “2020” problem. Points to note are 30 GW of wind generation, being 29% of peak capacity. It is important to note that minimum load on the GB system is around 30 GW. The increased generation plant margin (38GW on a 61GW system - 62%). This compares with a more normal plant margin of 20-25%. Considerable continued use of fossil fired generation. No significant use of energy storage or DSP factored into this scenario. Cost-effective storage technology is still not available and DSP is not well enough defined at present. Forecasting of the output of renewables is used but this area is still developing.
14
Challenges for 2020 - Transmission• Major new transmission
capacity required for both offshore and onshore wind
• Smart network options include:– New DC transmission
technology– New AC transmission
technology– Change in management of
transmission system (allocation of transmission rights and security of supply standards)
Presenter
Presentation Notes
There are major challenges for transmission (the use of High Voltage circuits at 400 kV and higher) to transmit the power from remote renewable to the load centres in London and other big cities. A number of new technologies may be considered: HVDC – particularly the use of Voltage Source HVDC. This is now available at ratings up to 1000 MW and DC voltages of +/- 300 kV. AC – use of power electronics (known as FACTS) to improve the control of AC circuits and also high temperature conductors to increase the current rating of circuits. More immediately, a change in the management of the transmission routes and the security and quality of supply standards that define the number of redundant circuits that are required. i.e. to make more intensive sue of existing assets. Of course loading assets more heavily allows more power to be transported but it will inevitably increase electrical losses.
15
Getting Renewables from ScotlandOption – Offshore HVDC
• Illustration of radical thinking now being undertaken.
• Multi-terminal Voltage Source HVDC transmission connecting both on-land and offshore wind farms
• Alternatives are on-land reinforcement of North South circuits as well as more effective management of existing assets
i
ii
Presenter
Presentation Notes
This is an illustration of the radical thinking that is going on to avoid the delays associated with planning and permitting. Here, ratter than try to construct new overhead line circuits, submarine cable circuits are considered that connect substations on the terrestrial system but also pick up offshore wind farms. This starts to resemble the offshore transmission grid that is proposed by a number of commentators to gather the power from a range of offshore renewables. As this requires multi-terminal HVDC systems (which do not yet exist) there is considerable development of the concept required.
16
Challenges for 2020 - Distribution
• Much on-shore low carbon will be connected at less than 150 kV (Distribution)
• Major equipment renewal programme required – but still no clear vision of the future
• At present very limited use of ICT
• Active Smart Networks
Presenter
Presentation Notes
Turning to Distribution circuits. These are lower voltage than Transmission circuits and operated radially. The circuits are passive with very little monitoring or control. Much of the onshore low-carbon generation will be connected to Distribution circuits with the added complication that much of the equipment was installed in the 1950s and 1960s and is now beyond its design life. Although it is widely recognised that this equipment must be replaced, there is no consensus as to what to replace it with. Although intuitively it would appear obvious to make much greater use of ICT, the costs of communication circuits, particularly those with no latency are such that this is often difficult to justify. Hence the Smart Networks contribution here is the development of active Distribution Networks
17
Distribution systems
Source: http://www.aura-nms.co.uk
Active Management- The primary purpose is to maximise the utilisation
of distribution network assets with increasingpenetration of DER
Presenter
Presentation Notes
This shows an example of a project on Active Distribution Networks The primary purpose of active management is to maximise the utilisation of distribution network assets with increasing penetration of Distributed Energy Resources. AURA-NMS is the name of the project. This diagram shows a possible active distribution network management system based on Aura-NMS controllers. The Aura-NMS controllers get measurements from the network, instruct the devices on the network to change their set points or Open/Close status based on the operating conditions. This concept uses Active Management controllers installed at each primary substation, although there are competing concepts based on applying an overall Supervisory Control and Data Acquisition System
18
UK Climate Change CommitteeDecember 2008
• Emission reductions written into primary legislation
• Decarbonisation of the power sector, starting now and through 2020s. Dominant Technologies likely to be Renewables (e.g. wind, tidal), nuclear and CCS
Presenter
Presentation Notes
In addition to the 2020 targets, we now have clear guidance that overall GHG emissions need to be reduced by 80% or more by 2050. In November of 2008, the UK Committee that sets these targets made the statement on implementation that “the power sector should be de-carbonised starting in 2020 with effective decarbonisation by 2030”. The options laid out were: Nuclear Fossil with CCS Renewables However, how to design and operate such a power system cost-effectively was not made clear and this seems to be a major challenge for university research to try to understand how this ambition might be achieved .
19
Features of the de-carbonised power sector
Generation• Renewables and constant
output plant (CCS and nuclear)
• Large plant margins limited by use of DSP and storage
• Variable energy pricing with active customer involvement
• Aggregation of local generation
Transmission/Distribution• Local micro-generation and
DG connected to Distribution• Large-scale remote
renewables requiring new transmission links
• Active control of transmission and distribution networks to limit capacity required
• Much greater use of ICT on Distribution.
Presenter
Presentation Notes
The features of the decarbonised power sector include Generation Renewables and constant output plant (CCS and nuclear). Very difficult to balance supply and demand and so maintain frequency. Large plant margins limited by use of DSP, storage and forecasting. We hope for energy storage technology and must learn how to use Smart Meters. There is considerable development required in forecasting the output of renewable generators Variable energy pricing with active customer involvement But what level of involvement does the customer wish? Aggregation of local generation Transmission/Distribution (their functions will merge) Local micro-generation and DG connected to Distribution. Tap-changers and better voltage control on Distribution circuits. Large-scale remote renewables requiring new transmission links Active control of transmission and distribution networks to limit capacity of plant required Much greater use of ICT on Distribution
20
Some pressing research questions
• How are smart meters to be used?– Demand reduction, frequency control, reserve, peak
shifting?• How can millions of small generators and
controlled loads be co-ordinated?– Does complexity science help us?
• How to communicate to domestic customers for Demand Side Participation?– What level of information do we need and want?
• Will a market solution work for both operation and planning of Smart Networks?
Presenter
Presentation Notes
I list here some of the pressing research questions How should Smart Meters be used? We know they can do many functions, but there is still great uncertainty as to what they should be used for. How can millions of small generators and controlled loads be co-ordinated? Is a hierarchical approach inevitable or are alternative coordination structures likely to be effective? How to communicate to domestic customers for Demand Side Participation? What level of information do we want and need? How can this information be presented to avoid the “rebound effect” and fatigue by customers when presented with this data? Will a market solution work for both operation and planning?. There seems to me to be a real question of whether Infrastructure Development can be left to the market and if it is centrally planned while the energy market is left de-regulated there are possibilities for major distortions.
