Presentation on theme: "Regulation in Electricity Supply"— Presentation transcript:
1Regulation in Electricity Supply NBS-MCLIMATE CHANGE GOVERNANCE AND COMPLIANCERegulation in Electricity SupplyThe changing face of the Electricity Market in the UKИзменяющееся лицо рынка электроэнергии в БританииN. Keith Tovey, M.A. PhD, C.Eng MICE Н.К.Тови М.А., д-р технических наукEnergy Science DirectorLow Carbon Innovation CentreUniversity of East Anglia, NorwichРуководитель по энергетическим исследованиямЦентр экологических инновацийУниверситет Восточной Англии, Норвич
2Course WEB Page http://www2.env.uea.ac.uk/energy/energy.htm or
3The changing face of the Electricity Market in the UK Изменяющееся лицо рынка электроэнергии в БританииA brief review of the UK Electricity Industry prior to 1990 under State Ownership.differences in approach between England / Wales and Scotland.Fuels used for generationFuel Diversity – The Shannon-Wiener IndexThe Electricity Markets in the 1990s after PrivatisationThe New Electricity Trading Arrangements NETA (2001)The British Electricity Trading and Transmission Arrangements (BETTA).The Supply of Electricity since 1990Conclusions
4Scotland (Шотландия): The Generation and Distribution of Electricity has always been different in Scotland compared to England and Wales(Шотландия всегда отличалась от Англии и Уэльса в плане производства и распределения э/э )Scotland ШотландияScotland (Шотландия):Two vertically integrated companies supplying discrete areas (Две вертикально интегрированных компании, снабжающие отдельные территории)England and WalesАнглия и УэльсNorthern IrelandСеверная ИрландияEngland and Wales (Англия и Уэльс):One Generating Company (CEGB) and 12 Regional Electricity Suppliers(Одна генерирующая компания (CEGB) и 12 региональных поставщиков).2000 MWEdFElectricité de France EDF
5England and Wales Англия и Уэльс Structure of Electricity Supply in early 1990s Структура системы энергоснабжения в начале 1990 г.г.ScotlandШотландияScottish HydroScottish PowerScotland ШотландияVertical Integration Вертикальная интеграцияtwo companies две компанииEngland & WalesАнглияи УэльсNorthernYorkshireEasternLondonEast MidlandsSEEBOARDSWEBSouthernNORWEBMANWEBMidlandsSWALECEngland and Wales Англия и Уэльс12 Regional Supply Companies 12 региональных компанийalso Distributed Network Operators а также распределяющие сетевые операторы
6Electricity Generation in the UK Производство электроэнергии в Великобритании Coal + OilNuclearGas (CCGT)RenewablesUntil 2006, growth averaged 1.8% over previous 20 yearsIn recent years gas has overtaken coal as dominant fuel and nuclear has declined
7Implications of daily/weekly/monthly variations in fuel use for Electricity Generation The carbon factor for electricity generation in UK is ~ 540g/kWhVaries fromHour to hourDay to dayWeek to weekMonth to monthSeeCurrent accounting only uses Grid annual average. In future accounting may relate to emissions associated with time of useThus a heavy industry with high electricity demand in day time could significantly reduce its carbon emissions by operating overnight rather than during day.
8Daily fuel mix in electricity Generation 11th January 2010
9Weekly fuel mix in electricity Generation 11 - 17th January 2010 Mon Tues Wed Thurs Fri Sat SunNotice higher proportion of coal used during day time hence a higher carbon emission factor.
10Shannon – Wiener Index of Fuel Mix Diversity The Shannon-Weiner Index (H) is defined as:H = - pI ln pIwhere pi is the proportion of the ith fuel.The index value increases with number of items and also the relative proportions of itemsWith three fuels, the maximum value reaches 1.09 when all the fuels are in equal proportions.In Norway where Hydro provides 99.5%, the index for the three fuels used is just
11Shannon – Wiener Index of Fuel Mix Diversity Shannon – Wiener Index is a measure of diversity originally developed as a measure of biodiversity.Higher index values occur with higher diversity.But there is no absolute upper limit.There is a maximum diversity index for a given number of fuels (e.g. species, fuels) when all items are in same proportion, but index will be higher for a greater number items.Index is low if one item dominatesVariation in maximum value of Index with number of items. The situation occurs when all items have equal proportion.e.g. with 6 fuel types the maximum value of index would be 1.8.
12Shannon – Wiener Index of Fuel Mix Diversity Exercise Selected link for EXCEL Spreadsheet Template
13Transmission Network in the UK Scotland ШотландияTransmission throughout England, Wales and Scotland became unified on April 1st 2005400 kV275 kVEngland and WalesАнглия и Уэльс132 kVHistorically transmission networks have been different in England and Wales compared to ScotlandИсторически, сети передачи э/энергии в Англии и Уэльсе отличались от сетей Шотландии
14Most Generating Capacity is in the North - most demand is in South MW+1643+7525-4709-1963+418Interconnector to ScotlandGenerating Capacity Surplus/Deficiton February 12th 18:00+ve: generating capacity exceeding demand-ve: demand exceeding generating capacityInterconnector to France
15Electricity Generation - pre 1990 Decision on how electricity was to be generated was done on a generating set basisGenerating Sets to run were selected on Merit Order.Based on Marginal Costs(i.e. the fuel costs - цены на нефть)Some generating sets were run OUT of MERIT ORDER where system constraints were an issue.Generators sold electricity to Regional Electricity BoardsElectricity Boards sold to consumers in their Area onlyPrices to consumers varied between regions
16Privatisation of Electricity Supply Industry 1990 Central Electricity Generating BoardЦентральноеNational PowerPowerGenNuclear ElectricCoal (Угольные) Fired Power StationsOil (Нефтяные) Fired Power stationsGas Turbine (Газовы турбины) StationsHydro Stations (ГЭС)Nuclear Stations (Атомные)Transmission (Трансмиссия)National Grid Company12 Regional Electricity Companies12 Regional Electricity Companies
18Comparison of Demand Forecast and Outcome Data for 48 hour period covering 27th and 28th September 2008Note: there was an alert on 28th from period 45 (i.e. 22:30) meaning no actual data is available from this time.
19Obtaining Information from BMREPORTS Total Demand for electricity on a half hour basis may be accessed from:INDO: Initial Demand Out-turnITSDO: Initial Transmission Demand Out-turn – includes transmission losses etcWhat is today’s demand: What are today’s wholesale prices?
20The changing face of the Electricity Market in the UK A brief review of the UK Electricity Industry prior to 1990.The Electricity Markets in the 1990s after Privatisationthe first system know as the “Pool”.Some Countries operate a derivative of the “Pool”Operation of the Pool – the bidding ProcessThe New Electricity Trading Arrangements NETA (2001)The British Electricity Trading and Transmission Arrangements (BETTA).The Supply of Electricity since 1990Conclusions
21Independents-Независимые Industry-Промышленность Scottish Nuclear (Атомная) *Scottish HydroScottish PowerConsumersПотребителиScotlandШотландияEngland and WalesАнглия и УэльсElectricité de FranceThePoolПулPowerGenLicensed SuppliersЛицензированные поставщикиConsumersПотребителиIndependents-НезависимыеBNFL (Magnox)Industry-ПромышленностьRECsSecond Tier ConsumersВторичные потребителиNuclear Electric *Eastern **Innogy
22The Operation of The Electricity Pool: 1990 – 2001 Only the Generators (>100 MW) bid into the POOL to supply electricity e.g. National Power (now Innogy), PowerGen etcThe National Grid Company published projected demands for the following day and invited bidsThe Generators supplied bids for each generating set in each station for each half-hour period of the following dayThe NGC sorted bids to determine which generating sets would be used for each particular period, and which ones would have capacity made available
23Companies up to and including B successful 1250 MWBid from company E £19.50 per MWh1250 MWBid from company D £19.40 per MWh1250 MW32500 MWBid from company C £19.32 per MWh1250 MWBid from company B £19.31 per MWh1250 MWBid from company A £19.20 per MWh (0.96R / kWh)Range of bids from companies in range £18 - £19 per MWhRoubles per kWhSystem Marginal Price= £19.31SMP10000 MWRange of bids from companies in range £15 - £18 per MWhRoubles per kWh10000 MWCompanies up to and including B successfulRange of bids from companies in range <£15 per MWh0.75 Roubles per kWh10000 MW£1 ~ 50 Roubles
24The Operation of The Electricity Pool All Companies who were successful were paid the SMP for all units generated irrespective of what their bid wasThe bids were for the single half-hour period and fresh bids were required for all half hour periodsIt was possible for companies to bid £0 and this would guarantee that they generated and paid SMPHowever, if all Companies did the same they would have to generate electricity for nothingIn addition to the SMP, there was also a capacity charge relating to the generating capacity which was requested to be available
25The Operation of The Electricity Pool Capacity Charge paid to all Generators who had been requested to have capacity available.-based on formula(по формуле):LOLP * (VOLL - SMP)Loss of Load ProbabilityValue of Lost LoadVOLL: was set by the Regulator at around £2400 per MWHLOLP: normally a very low figure but could become significant if there was a shortfall in generatingCapacity Charge: signal to ensure sufficient capacity was available.Pool Input Price (PIP) = SMP + LOLP * (VOLL - SMP)
26System Constraints (Система давления): Электрический пулSystem Constraints (Система давления):Some Power Stations constrained “ON” to ensure security of supply even when their bid was more expensive(Некоторые электростанции constrained “ON” обеспечить снабжение, даже в случае более дорогих заявок)Some Power Stations constrained “OFF” even when their bid was cheaper (-excess of capacity in one region)(Некоторые электростанции constrained “OFF” обеспечить снабжение, даже в случае более дешевых заявок)Constrained Stations paid their “Bid” Price(уплачивали их «заявочную» цену)POOL Output Price: (POP) = Pool Input Price + UpliftUplift represented the additional charges incurred to National Grid Company because of System ConstraintsSuppliers purchased Electricity at Pool Output Price(Поставщики закупают э/э на Пуле по цене производителя)
27Электрический пул: A Review Need for strong Regulatory Body to ensure prices were not fixed.Evidence suggested price manipulation took place in early years.Regulator required major generators to dispose of some stations.The lack of Demand Side Bidding was a weaknessCharges for Transmission Losses were averaged over whole Network.Customers in North subsidised those in SouthGenerators in South subsidised those in NorthThese issues have been partly resolved under BETTASeparate discussions relating to Distribution Chargesare also under way
28Changes in Regional Electricity Companies in the 1990s Take-overScottish Power takes over MANWEBScottish & SouthernVertical IntegrationnPower acquire MidlandsPowerGen acquire East MidlandsScottishPowerUnited UtilitiesUnited Utilities formedin NORWEB areaPowerGennPowerMergersScottish Hydro & Southern become Scottish & Southernc. 1998
29The changing face of the Electricity Market in the UK The New Electricity Trading Arrangements NETA (2001)The British Electricity Trading and Transmission Arrangements (BETTA).BETTA essentially extended NETA to cover Scotland.There were few changes in England and Wales apart from Transmission issuesOperation of the Trading Market remained the sameAlthough minor modification take place all the timeIn BETTABoth Generating and Demand Side Bidding Takes PlaceMost Electricity is traded outside Balancing MechanismFavours those who guarantee specific levels of generation/supply in advanceFavours those who can guarantee flexibility in output / demand at short notice.
30Operation of BETTA The basic principles Основные принципы Generators and Suppliers are penalised if they deviate from their agreed level of generation / supply.System security is maintained via the Balancing MechanismRenewable Generators e.g. Wind and small CHP (~10 MW) can be adversely affected.Generation and Supply focuses on:Balancing Mechanism (BM) UnitsGenerating BM Units: Demand BM UnitsTrading between Generating and Demand BM UnitsOnly the volume traded ( not price) has to be notified.
31Operation of Balancing Mechanism NETA/ BETTA The Balancing Mechanism: A SummaryInitial Physical Notification (IPN) – 24 hours in advanceSystem Operator checks sufficient capacity is available.Final Physical Notification (FPN)Gate Closure for Real Time Period of 30 minsInitially 3.5 hours before REAL Timelater reduced to 1 hour.Day BeforeCurrent DayRealTime30minsIPNFPN1 hour3.5 hoursGate ClosureOperation of Balancing MechanismChanges to contract position cannot be made after Gate ClosureBalancing Mechanism provides System Security
32NETA/ BETTA: Operation of the The Balancing Mechanism: Generators and suppliers are penalised if they deviate from their contract position at the final physical notification (FPN).The System Operator negotiates with balancing Mechanism (BM) units to increase/decrease the amount of electricity available to maintain system security and ensure system remains stable.Case 1:Too little electricity on the systemGenerators can OFFER to INCREASE outputSuppliers can OFFER to REDUCE consumptionTimeFPNOFFERTimeFPNOFFERIf OFFER is agreed then Generators / Suppliers are PAID for any electricity increased / reduced under the OFFER.Separate charges apply for these services.
33The New Electricity Trading Arrangements Новая система оптовой торговли НЕТАThe Balancing Mechanism Балансирующий механизмTo allow system to remain stableToo little electricity on the systemGenerators can OFFER to INCREASE outputSuppliers can OFFER to REDUCE consumptionTimeFPNOFFERTimeFPNOFFERIf OFFER is agreed then Generators / Suppliers are PAID for any electricity increased / reduced under the OFFER.
34The New Electricity Trading Arrangements Case 2: Too much electricity on the systemGenerators can BID to REDUCE outputSuppliers can BID to INCREASE consumptionFPNOFFERBidTimeTimeFPNOFFERBidIf BID is agreed then Generators / Suppliers PAY for any reduction in generation / increase in demand under the BID.
35The Balancing Mechanism: Offers and Bids Generators / Suppliers may submit OFFERs or BIDs which differ for different levels of deviation from the Final Physical NotificationMW: £30 per MWh (1.5 Roubles per kWh)MW: £50 per MWh (2.5 Roubles per kWh)MW: £20 per MWh (1 Rouble per kWh)FPNокончательная физическая нотификацияExample of Differential Offers from a GeneratorNational Grid Company normally accepts OFFERS / BIDS which are cheapest unless System Constraints prevent this.
36The Balancing Mechanism: Undo Offers/Undo Bids What happens if System Operator has got it wrong?OFFERs / BIDs cannot be cancelledUNDO BID removes an OFFER and is usually less than the OFFERUNDO OFFER removes a BID and is usually more than the BIDOFFERs / UNDO BIDs [ or BIDs / UNDO OFFERs] are submitted in pairsOFFER / UNDO BID: Pair +2OFFER / UNDO BID: Pair +1FPNBID / UNDO OFFER: Pair -1BID / UNDO OFFER: Pair -2
37The Balancing Mechanism: Imbalance Charges Charges for imbalance depend on whether BM unit is deviating in same direction as overall system or not.Example shows cases where imbalance is in same direction as systemActual Metered VolumeFPNPaid SSPActual Metered VolumeFPNPays SBPУстановлено в двустороннем порядке договаривающимися сторонамиSettled bilaterally between contracting partiesУстановлено в двустороннем порядке между сторонамиSettled bilaterally between parties
38Distributed Network Ownership in 2005 Regional Supply OwnershipScottish & SouthernUnited UtilitiesCE Electric UKWestern PowerPowerGenAquilaIberdrolaScottish PowerUKPower NetworksElectricité de FranceWestern PowerCentral NetworksDistributed Network Ownership Владение распределительной сетиScottish & SouthernnPowerE.ON (PowerGen)Electricité de FranceScottish PowerIberdrolaIn 2007, Scottish Power became part of Iberdrola
39Changes when BETTA came into force – April 1st 2005 Integrated Trading System operating England and Wales with ScotlandBefore BETTASystem and Transmission Network Operator in England and Wales was National Grid Company (NGC).System and Transmission Network Operator in South of Scotland was Scottish PowerSystem and Transmission Network Operator in North of Scotland was Scottish and SouthernAfter BETTANational Grid Company become System Operator for whole of England, Wales and Scotland.NGC now Transmission operator for England and WalesIn Scotland the two companies now hold the respective transmission Network LicencesIssues of differences in Transmission Protocol had to be resolved – including the use of the Inter connectorCharges for Transmission Losses had to be addressed
40Impact on System Sell and Buy Prices Sunday 6th December 2010Monday 7th December 2010Example of System Sell Price (SSP) and System Buy Price (SBP) corresponding with First Point of Triad
41Impact on Wholesale Charges How well has it performed since starting on 27th March 2001?Completion of Langeled Gas Line to NorwayUK becomes net importer of gasOil reaches $140 a barrel41Wholesale prices rose rapidly in 2004/2005, fell sharply from mid 2006, rose rapidly since mid 2007 then fell but are less stable.
42Generator Connection Charges under BETTA Плата за подключение к генератору энергоснабжения по BETTA 1A> £25 per kW4325B£20 to £25 per kW1079C£15 to £20 per kW8612D£10 to £15 per kW11131914162015E£5 to £10 per kW18F£0 to £5 per kW242122172526G- £5 to £0 per kW2327H- £10 to -£5 per kW4242
43Generation Connection Charges from April 1st 2013 No.Zone NameTariff (£/kW)1North Scotland2East Aberdeenshire3Western Highlands4Skye and Lochalsh5Eastern Grampian and Tayside6Central Grampian7Argyll8The Trossachs9Stirlingshire and Fife10South West Scotland11Lothian and Borders12Solway and Cheviot13North East England14North Lancashire and The LakesNote: Updated Values on those in handout and current as of October 2013These are general charges for each area in addition there are additional charges reflecting the capabilities of the local regions around each substation
44Generation Connection Charges from April 1st 2013 No.Zone NameTariff (£/kW)15South Lancashire, Yorkshire and Humber16North Midlands and North Wales17South Lincolnshire and North Norfolk18Mid Wales and The Midlands19Anglesey and Snowdon20Pembrokeshire21South Wales22Cotswold23Central London24Essex and Kent25Oxfordshire, Surrey and Sussex26Somerset and Wessex27West Devon and CornwallIn addition there is a local sub-station tariff which varies from as much as £ per kW at Edinbane on Skye in the SHETL areato as little -£ per kW at Mark Hill in the SPTL area.
45Demand Connection Charges 2012 - 2013 Beware!!!!The TRIAD Approaches!!!on 1st November!What is the TRIAD?A modified measure of peak demand over winter period
46Demand Connection Charges 2012 - 2013 The Triad occurs in the period 1st November – 28th/29th FebruaryIt is the mean of the following:The maximum demand in any one half hour in the above time period.The second highest demand in any one half hour provided it is separated from (1) by at least 10 days.The third highest demand in any one half hour period provided that it is separated from (1) and (2) by at least 10 days
47Demand Connection Charges from April 1st 2013 Energy Consumed (p/kWh) Demand Zone NameTRIAD Demand (£/kW)Energy Consumed (p/kWh)1Northern Scotland2Southern Scotland3Northern4North West5Yorkshire6N Wales & Mersey7East Midlands8Midlands9Eastern10South Wales11South East12London13Southern14South WesternThis table has updated figures for 1st October 2013
48Example how TRIAD charges can be mitigated Peak demand occurs at time of TRIAD - form process workingShift process by say 2 hours will reduce the TRIAD charge by over 25% or £ see handout
49NBS-M017 2013 CLIMATE CHANGE GOVERNANCE AND COMPLIANCE 8. Regulated Power Zones and Smart GridsRecipient of James Watt Gold MedalN.K. Tovey (杜伟贤) M.A, PhD, CEng, MICE, CEnvН.К.Тови М.А., д-р технических наук494949
50REGULATED POWER ZONESTransmission and Distribution Networks are critical to electricity security.Losses on line:= I 2 R where I is the current and R is resistancethe power transmitted P = V * I V = voltageTypical UK domestic voltage VEuropean Voltage VNorth American Voltage VThese are nominal voltages and system must control voltages within a narrow band of this.Voltage%loss relative to 240 V240100.0%11000%33000%132000%400000%Losses are reduced by increasing voltage
51REGULATED POWER ZONESThe consequence of resistive losses is that the transmission and distribution cables heat up and may typically be running at 50o C+As they heat up they expand and the cables will sag more at mid-span with a the possibility of a flashover.This means that there will be less sag when the cable temperature is lower – i.e. in winter and also in times of higher wind speeds when the cooling effect of the wind will be greatest.There is thus a maximum power load that any cable can take and this limits the number of connections that can be made.A further problem with AC transmission is that current flows mostly through the skin with much of the cross section not used effectively.Unlike DC
52REGULATED POWER ZONESTraditional way to allocate generation connections:Order of application according to potential maximum connection capacity up to total capacity of transmission/distribution line.A safe approach which ensures that transmission/ distribution lines are not overloaded.BUTMay not make optimum use of transmission capacity.Example:Suppose a line has 2000 MW capacity – a typical 400 kV ciruit capcityOrder of connection allocations:Generator 1: MW – say with 2 x 500 MW setsGenerator 2: MWGenerator 3: MW – with 2 x 250 MW sets.
53Total installed capacity REGULATED POWER ZONESGenerating SetsTotal installed capacityGenerator 12 x 500 MW1000 MWGenerator 21 x 500 MW500 MWGenerator 32 x 250 MWIf all sets are generating – 2000MW i.e. capacity of line and no more sets can connect without the expense of transmission line upgrade.If generating sets are fossil fuel, then they may have a relatively high load factor and traditionally that has not been a problem.BUT if say one of Generator 1’s sets is not generating, only 1500 MW of the 2000 MW of the line capacity is used.BUT no new generators can connect as the inactive set may come back on line.Grandfathering Rights
54REGULATED POWER ZONESProblem is exacerbated with generating plant of low load factor e.g. wind and was first identified in Orkney where significant renewable generation threatened to seriously overload distribution system.Orkney is connected to mainland by 1 x 30 MW and 1 x 20 MW cable. A fossil fired power station on Flotta associated with the oil terminal must run for safety reasons typically around 4.5 MW.Burgar Hill had historic rights of around 7 MW with the European Marine Energy Centre (EMEC) a further 7MW also in this category.Thereafter there were several other wind developments which threatened to exceed total capacity of cables to mainland as it was assumed that one of the two cables might be out of action giving only a maximum potential connection capacity of 20 MW.
55REGULATED POWER ZONES Total Historic Generating Capacity ~ 18.5 MW Minimum Demand in Orkney ~ MWCapacity of smaller cable to mainland ~ 20 MWMaximum Generation on Orkney which would not overload single mainland cable is27 MW – i.e MW new capacity could be connected.But EMEC capacity is often 0 MW, and rarely is Burgar Hill at its rated output.If dynamic dispatch of generation capacity is used much more generation could be connected.
56REGULATED POWER ZONES Evaluate total system capability at any one time C = mainland connection capacity (i.e. 20 or 30 or 50 MW)+ instantaneous demand on OrkneySubtract from this those generating connection which have grandfathering rights, but only up to the amount of instantaneous generation (NOT maximum connection rights)This gives maximum additional capacity which can be connected at that time.If this also is done on a first application first served basis, it would be possible to connect much more renewable generation than otherwise possible.However, it may mean that wind turbines at the end of the queue may not be able to generate when wind speed is optimum and returns on investment are best
57REGULATED POWER ZONESSuppose C = MW – i.e. both cables operating and demand is 10 MWIf Flotta output is 7 MW and EMEC is 7MW and Burgar Hill say 3.5 MW (i.e less than rated connection of 7MW as wind speed is low – i.e. instantaneous load factor is 50%)Available additional connection is 60 – 17.5 i.e 42.5 MWIf this were take by additional Wind at 50% load factor then 85 MW of additional capacity could connect.BUT if wind speed increased to rated speed of wind turbines, Burgar Hill would now be at 7 MW and available capacity would be 39 MW.If all of this were as wind turbines at rated output (i.e. 100% load factor) only 39 MW could actually generate and 46 MW would have to shut down at the time they were most productive.
58REGULATED POWER ZONES Consequence of Dynamic Regulation of Power Zone More effective use of transmission/distribution cables is madeA greater proportion of renewable energy can be brought on line at an earlier stageBUTThose connecting last may find return on investment poor.Lincolnshire RPZ operates only to transmit power from offshore wind farmDoes not primarily address demand, but cooling effect on cables to minimise sagIn winter – higher wind speeds – greater output capacity from wind turbinesBUT weather is cooler and cooling effect of wind on cables is greater so cables can transmit more
59SMART GRIDS – DYNAMIC REGULATION of DEMAND ELECTRIC VEHICLES: Widespread deployment of electric vehicles could adversely affect the generation of electricity – leading to less effective use of generating capacity.Existing peak demand occurs around 17:00 the time when most people return home .Owners would potentially would start charging their vehicles potentially exacerbating the load profileElectric Vehicle demand from Dave Openshaw
60SMART GRIDS – DYNAMIC REGULATION of DEMAND Electric Vehicles with Smart ChargingStrategy 1:Unrestricted charging as per previous slideStrategy 2:Encourage people not to charge between 17:00 and 21:00 with a reduced tariff.Assume 75% take this up~ would remove light green area.Strategy 3:Discharge remaining store in car batteries to help existing peak. i.e. move green area to red – at further reduced tariff – example shows 25% of people adopting this.
61SMART GRIDS – DYNAMIC REGULATION of DEMAND HEAT Pumps: Widespread deployment of Heat Pumps would exacerbate electricity demandHeat Pump demand from Dave Openshaw
62SMART GRIDS – DYNAMIC REGULATION of DEMAND There is a less “peaky” demand from heat pumps than electric vehicles because of thermal store benefits from under floor heating, Use of an additional thermal store could help further to fill mid-day peak and lop peak morning and evening periods for charge overnight.