Smart Energy and Smart Grids Future challenges and smart solutions for the electricity system

Transcription

1 Smart Energy and Smart Grids Future challenges and smart solutions for the electricity system UKERC Summer School Wyboston Lakes 7 July 2015 Dave Openshaw

2 UK Power Networks Consumers Million Service Area km² Underground Network km Overhead Network km Energy Distributed TWh Peak Demand GW , ,024 46, UK Power Networks holds three electricity distribution licences: EPN (serving the East of England) SPN (serving the South-East of England) and LPN serving the bulk of London 2

3 GB electricity system topology 132,000 volts 33,000 volts Wind farms Solar PV farms 400,000 and 275,000 volts 25,000 volts Distribution substation 11,000 volts Railway supplies 11,000 volts Primary substation 400/230 volts National Grid entry point exit point Distributed Generation I&C consumers SME consumers Domestic consumers Homes with Street furniture micro-generation Electricity transmission is at 400kV or 275kV in England and Wales (also 132kV in Scotland) - typical electricity distribution voltages are 132kV, 66kV, 33kV, 11kV, 25kV (rail traction) and 400/230V Major power stations, large offshore windfarms and European interconnectors are connected to the transmission system but renewable generation (mainly onshore wind and solar PV) and CHP is now increasingly being connected to distribution systems UK Power Networks. All rights reserved 3

4 Future challenges and smart solutions Context The UK Carbon Plan Future energy scenarios Implications for supply and demand Future generation scenarios DG and micro-generation scenarios Demand growth scenarios EV charging and heat pump demand scenarios Wider system implications Frequency stability Power quality Voltage management Smart solutions Smart metering Smart grid solutions Overall implications for the electricity distribution business model The evolution from passive to smart DNO The transition from smart DNO to Distribution System Operator 4

5 Decarbonisation the role for renewable generation, heat and transport The Carbon Plan sets out how the UK will achieve decarbonisation within the framework of energy policy: to make the transition to a low carbon economy while maintaining energy security, and minimising costs to consumers The UK renewable Energy Roadmap identifies a range of renewable generation technologies which will make a significant contribution to UK s 15% by 2020 renewable energy target Renewable heat, heat pumps and electric vehicles will displace conventional fossil fuel based technologies and further contribute to UK s decarbonisation targets The UK Solar PV Strategy has the ambition of approaching 20GW of solar PV capacity early in the next decade (from 2020) 5

6 Future energy scenarios (National Grid) Source National Grid Future Energy Scenarios National Grid has developed four energy scenarios which consider different futures for electricity Gone Green, Slow Progression and Low Carbon Life all emphasise low carbon generation but whilst GG and SP assume large scale renewables, LCL assumes a greater contribution from micro-generation and DG GG and LCL both assume significant growth in EVs but only GG assumes significant growth in heat pumps. No Progression reflects economic constraints on achieving decarbonisation ambitions 6

7 Implications for supply and demand 7

8 Future generation scenarios solar offshore wind nuclear gas CCS onshore wind interconnectors Source National Grid Future Energy Scenarios 8

9 Low Carbon Life DG and micro-generation projections Distributed generation with installed capacity above 1MW DG and micro-generation with installed capacity below 1MW This scenario implies a major shift from centrally dispatched synchronous generation to widely distributed - but intermittent - forms of generation Source National Grid Future Energy Scenarios Scenario: Low Carbon Life 9

10 Penetration of renewable generation (example EPN network) Peterborough Cambridge Kings Lynn Norwich Ipswich Significant areas of UK Power Networks EPN region are now approaching DG saturation levels Across UKPN, accepted connection offers for DG developments >5MW have been received for: MW of solar PV - 343MW of onshore wind - 605MW other Luton Aylesbury Chelmsford Tilbury UK Power Networks. All rights reserved 10

11 Electricity demand scenarios These charts show the wide variations in peak power demand and annual consumption under different scenarios Low Carbon Life and Gone Green are characterised by significant demand increases but with different trajectories albeit converging beyond 2025 Under No and Slow progression, demand continues to fall with little or no recovery Source National Grid Future Energy Scenarios 11

12 EV and heat pump demand Source National Grid Future Energy Scenarios Gone Green and Low Carbon Life project high exponential growth in EV demand Gone Green projects a similar growth rate in heat pump demand Under Slow and No Progression EV demand growth accelerates slowly 12

13 Wider system implications 13

14 Frequency stability challenges Wind and solar PV generation has minimal short-run marginal cost of production and hence will always have higher merit order than other generation technologies (even nuclear) Hence under future low demand / high (wind and solar PV) generation scenarios, synchronous generation will be constrained off In these circumstances, system inertia will be low resulting in reduced frequency stability (higher rate of change of frequency) In the event of a major loss of infeed this will lead to an enhanced risk of frequency collapse leading to wide scale supply interruptions including operation of low frequency demand disconnection relays Source National Grid System Operability Framework 14

15 Power quality challenges A further consequence of reduced synchronous generation is lower system strength Under future low demand / high (wind and solar PV) generation scenarios system fault levels will decline well below current levels This will lead to power quality challenges in the form of deeper and more prolonged voltage dips and increased harmonic distortion A further effect will be a possible system resonance shift to lower order harmonics Source National Grid System Operability Framework 15

16 Voltage management challenges Reactive / real powwer ratios are declining i.e. reactive exports at GSPs are falling faster than power exports A number of possible reasons e.g. increased cable capacitance, less reactive demand, energy efficient lighting (CfLs exporting VArs) and distribution connected solar PV At many GSPs distribution networks are exporting VARs to the transmission system in 2013 DNOs were net suppliers of reactive power to the transmission system for 39% of the time REACT project (NG led with DNO support) is exploring reasons but no firm conclusions as yet ENTSO-E Demand Connection Code may disallow VAr exports from Distribution to Transmission systems If this trend continues, DNOs will need to develop more comprehensive voltage management techniques The T&D interface is not unique DNOs may begin to experience issues at each voltage transformation stage HV/LV substations will be particularly challenged due to continued proliferation of rooftop solar PV Source National Grid System Operability Framework 16

17 Smart solutions 17

18 Smart metering system Smart Electricity Meter Comms Hub Data via two communication service providers (CSP) and one data service provider (DSP) each contracted to DCC CSPs - Arqiva (North) Telefonica (Midlands & South) WAN technology: long range radio and GPRS DSP - GGI Single licensed Data Communications Company (DCC) Capita DCC Central Hub In-Home Display Micro-generation (FIT) meter Home area network (HAN) technology: 2.4GHz and 868MHz ZigBee Network Operator Asset Management & Control Centre Power status polling Load switch operation Messaging Power outage alerts Voltage level (hh avg. rms) Hi/Lo voltage alert Extreme Hi/Lo voltage alert Voltage sag/swell log MD (hh avg.) 4Q hh profile HH consumption Messaging Tariff change etc. Consumer Access Devices / Smart Appliances Network Operator Revenue Management D Flows DUoS charges Suppliers From DCC Live (2016) and up to completion of rollout (2020?) DNOs will have an increasingly comprehensive (and necessary) suite of LV network utilisation data along with real-time power outage and power quality data But processes and systems will be necessary to extract the benefits whilst meeting the licence obligation regarding protection of data privacy UK Power Networks. All rights reserved 18

19 Smart grid solutions (example UKPN projects) UK Power Networks is developing and trailing a range of smart grid solutions to the emerging low carbon challenges to our business. Some of these projects combine technological and commercial innovation to provide solutions not only to resolve local network challenges but also the wider GB system challenges 1. Low Carbon London - industrial & commercial demand side response 2. Low Carbon London residential dynamic time-of-use tariff 3. Flexible Plug & Play Networks smart grid and communications technologies and active network management to provide headroom for renewable DG 4. Smarter Network (electricity) Storage distribution network and wider system support 5. KASM (Kent Active System Management) management of a highly active network through a contingency analysis tool minimising constraints on DG export 6. Fault Current Limiter creating additional headroom for urban DG Further information on UK Power Networks smart grid projects can be found on our innovation website: 19

20 Case Study 1 - Low Carbon London - I&C Demand Response The challenge highly loaded substations requirement to design to remain firm under n-1 typically brief periods when substation is out of firm extremely expensive and disruptive grid reinforcement 4 x 15MVA 33/11kV The opportunity intact N-1 I&C customers with flexible demand and/or standby generation air cooling load, industrial scale refrigeration, supermarket lighting Ideally dispatching post-fault and only when demand exceeds firm capacity (to minimise constraints on availability of DSR for other purposes e.g. flexible STOR / DSBR) obviating the need for costly and disruptive network reinforcement maximising capability of DSR to provide whole-system benefits The LCL trial 18MW of DSR - 77% generation, 23% demand turn-down - procured across 37 sites Dependability assessed at 70 80% for generation, 54 64% for demand turn down Sufficient confidence to defer 43m reinforcement for UKPN s networks over ED1 20

21 I&C Demand Response required demand response for various demand characteristics Demand above firm capacity Firm capacity Potential DSR dispatch event Demand Note: DSR dispatch would normally occur only under unplanned network single circuit outage conditions hence potential conflict with other calls on DSR (e.g. STOR) is small (esp. summer peaking substations) Source: Poyry Low Carbon London Project synergies and conflicts in the use of DSR for national and local issues 21

22 Case Study 2 Low Carbon London residential dynamic time-of-use tariff tariff Trial purpose: to investigate the network demand impact of dynamic ToU Tariffs designed to maximise usage of zero carbon / marginal cost generation Economy Alert tariff details: Designed by EDF Energy 1100 trial participants (plus control group) 12 month trial Smart meters installed by EDF Energy Emulating wind following tariff based on historic wind data reflecting day-on-day and within day variation in generation output Strong price (per kwh) signals 67.20p HIGH 11.76p NORMAL 3.99p LOW Min 24 hour notice Message delivered via IHD with SMS option 22

23 Dynamic Time of Use Tariffs Results High price Default price Low price Mean DSR (kw) Household performance rank Rank against of households measured DSR, by price band 23

24 Dynamic Time of Use Tariffs Consumer behaviour insights As anticipated, wet appliances appear to have the greatest flexibility Tariff complexity appears not to be an issue for most consumers Many appeared to welcome the organisational planning imposed by the day-ahead pricing notification In general, customers appear to be keen to participate in Time of Use tariffs Appliances for which households reported flexibility in avoiding high prices on the tariff 24

25 Case study 3 - Flexible Plug & Play Networks facilitating renewable generation The Challenge: Generator dominated network Additional wind and solar PV farms wishing to connect Existing network constraints Potentially prohibitive connection charges Unacceptable delays in connection Undermining business case for projects 25

26 Flexible Plug & Play Networks The Solution: Dynamic line ratings Active DG management Quad booster IEC communications Innovative contracts quotabased DG curtailment quad booster Current status: 54.40MW of accepted offers (15 projects) within the trial area of which 24.75MW is now connected radio mesh comms Expected annual curtailment given anticipated diversity of output with current mix of generation ~2% 26

27 Case study 4 - Smarter Network Storage grid-scale electrical energy storage (Leighton Buzzard) 6MW / 10MWh Li Ion Battery Installed adjacent to Leighton Buzzard 33/11kV substation Restoring firm capacity to the substation and avoiding need for a 3 rd 33kV circuit and 33/11kV transformer Batteries charged during off-peak periods available for dispatch in the event of an outage during a peak period Battery and power electronics enclosure Li Ion batteries Market opportunities include: - Power Purchase Tolling Agreements with Suppliers - TRIAD avoidance - STOR and Fast Reserve service to the SO - Dynamic and Fast Frequency Response services to the SO 27

28 Smarter Network Storage leveraging the capability across the supply chain 28

29 Smarter Network Storage Functionality Peak Shaving SNS uses its stored energy to meet peak demand which reduces the load on the network. This defers the need for network reinforcement to meet peak demand. Frequency Regulation SNS can regulate the grid frequency through power exchanges. This assists National Grid in stabilising the frequency of the wider electricity system. Reactive Power Support SNS has 7.5MVAr of reactive power capability. Reactive power can improve power factor, reduce losses and support voltage levels on both the local network and wider system Reserve SNS provides reserve capacity and can be triggered remotely to export power. This assists National Grid in balancing electricity demand and supply. Tolling / Wholesale Market SNS can provide energy based on a given energy delivery profile. This can be used to manage imbalance risk and assist in hedging against peak electricity prices; including reducing TRIAD charges for Suppliers 29

30 Case study 5 Kent Active System Management (KASM) Network runs interconnected with NG transmission system 650MW of connected generation (mainly wind) 300MW additional generation seeking connection (mainly solar PV) Two existing interconnectors (France 2GW and Netherlands 1GW) Two additional interconnectors planned (1GW France and 1GW Belgium) 30

31 KASM - Contingency Analysis Tool Multiple scenarios for variable generation export and interconnector flows Parts of distribution network approaching reverse power limits 34 contingency scenarios need to be analysed Worse case scenarios surrounding minimum demand / maximum generation (no diversity) and unplanned outage Need to be able to quickly determine generation constraint actions Essential to have realtime monitoring and contingency analysis capability 31

32 Case study 6 - Short Circuit Level Management Features and benefits: Fault Current Limiter (pre-saturated core) HV fault current / voltage dip limiting Maintaining low source impedance Allowing greater penetration of DG 32

33 Implications for the electricity distribution business model 33

34 The current evolution from passive to smart DNO Traditional Distribution Network Operator Managing a Largely Passive Network Passive - Smart Transition Smart Distribution Network Operator Managing an Increasingly Smart Network Smart Grid Technologies to Support an Active Network Advanced Control Room Operating & Network Visualisation Systems Active Network Management Self- Reconfiguring Networks On-line Diagnostics PMUs Monitoring & State Estimation Advanced SCADA & Telecommunications Actively Dispatched DSR & DG Phase Shifting Transformers Network Connected Storage Fault Current Limiters Integrated Voltage & PF Control D-Stacoms & Switched Capacitors Voltage Regulators & Phase Balancers Dynamic Line & Plant Ratings Adaptive Protection Network Meshing & Soft NOPs 34

35 The future evolution to Distribution System Operator Smart Distribution Network Operator Managing an Increasingly Smart Network Future Distribution System Operator Managing an Active Network and Supporting System Balancing Smart Grid Technologies to Support an Active Network Flexible Demand Di s patchable Resources DNO DSO Transition Electric Vehicles Heat Pumps Air Cooling Smart Appliances Energy Storage Distributed Storage DG Constraining on/off Contracts Demand Response Balancing & Reserve Services Suppliers & Intermediaries Transmission Balancing & Reserve System Services Operator Flexible Tariffs Customer Services Home Energy Services Commercial Building Energy Services Smart metering Energy Efficiency Ancillary Services Commercial Aggregation Virtual Power Plants Demand Side Management Balancing & Reserve Services Reactive power System Balancing Frequency Control & Constraint Management Black Start Ancillary and Commercial Services Frequency Response STOR / Flexible STOR Fast Reserve Demand Side Balancing Reserve Supplemental Balancing Reserve Pre-Gate Closure Contacts Pre-Gate BM Unit Transactions Bid Offer Acceptances 35

36 Thank you