Electricity Storage for Large Enterprises Andrew Pimm Centre for - PowerPoint PPT Presentation

School of something School of Chem. and Proc. Eng. FACULTY OF OTHER FACULTY OF ENGINEERING Electricity Storage for Large Enterprises Andrew Pimm Centre for Integrated Energy Research Energy storage workshop at University of Leeds 14 June 2016

Introduction Energy storage of interest to businesses/universities/hospitals, particularly those with on-site generation Economics of storage to enterprises poorly understood Many revenue streams exist Lancaster University interested in installing electricity storage

Case Study on Lancaster University 3 8 Maximum Monthly Demand Monthly Elec. Import (GWh) Carried out case study with Lancaster 2.5 6 2 University after presentation given there in 1.5 4 1 January 2016 (MW) 2 0.5 0 0 J F M A M J J A S O N D Month 13k students, 4.5k staff, 8 halls of residence 2014 (import) 2015 (import) on campus 2014 (MD) 2015 (MD) Annual elec. demand ≈ 22 GWh; spend ≈ £2m pa MD ≈ 6 MW 2014 4 2.35 MW wind turbine, 50 kW PV and 1.9 Monthly Elec. (GWh) 3 MWe CHP on-site 2 1 2 days w/o power in early Dec due to floods 0 J F M A M J J A S O N D Energy Manager (Jan Bastiaans) interested Month in installing up to 4MW / 4MWh of mixed Import WT CHP storage devices

Electricity Prices Price made up of commodity and non-commodity components Non-commodity = DUoS + TNUoS + RO + FiT + BSUoS + BS + HDC Commodity price set after forward purchase and trading by broker (Inenco) Green DUoS Time Band Red Time Amber Time Green Time Time periods Band Band Band Amber 09:00 - 16:00 00:00 - 09:00 16:00 – 19:00 Mon to Fri 19:00 - 20:30 20:30 - 24:00 00:00 - 16:00 16:00 – 19:00 Sat and Sun Red 19:00 - 24:00 DUoS charges for HV meters in north west region 0% 20% 40% 60% 80% 100% % of marginal price DUoS REO BS BSUoS HDC FiT Energy Cost (avg.)

Electricity Prices Time-varying marginal price is of interest to storage operator LU’s marginal price of electricity, 04/2015 -04/2016 (Mean commodity price of ~£0.06/kWh used, not including Triads)

Transmission Network Use of System (TNUoS) Charges HH metered customers charged for use of transmission network according to consumption during “Triads” Triads: 3 half-hours of highest GB system demand between Nov-Feb (separated by at least 10 days) Since 1990/91, >80% have been 17:00-17:30 Triad alerts issued by electricity suppliers and utility management companies

Optimisation Algorithm Modified arbitrage optimisation algorithm to take into account generation and demand (excess generation effectively costs the storage 4.91 p/kWh) Results below for no generation… currently trying to work out how to synthesise total demand and so half-hourly export based on monthly export figures

Optimisation Algorithm Modified arbitrage optimisation algorithm to take into account generation and demand (excess generation effectively costs the storage 4.91 p/kWh) Results below for no generation… currently trying to work out how to synthesise total demand and so half-hourly export based on monthly export figures

Savings Breakdown Breakdown of savings available to Lancaster University and required expenditure. • 2015 demand data & charges • 85% round-trip efficiency • t ch ≤ 12.5 hrs • t dch = 2 hrs • Hitting all Triads

Total Savings Total annual savings available to Lancaster University = £27,000/MWh Total savings • 2015 demand data & charges • 85% round-trip efficiency • t ch ≤ 12.5 hrs • t dch = 2 hrs • Hitting all Triads

DUoS for HV HH Metered (p/kWh) TNUoS Demand Area ID Area Red Amber Green (£/kW) 80 10 Eastern 6.384 0.020 0.004 46.543113 69.83 Value of Storage (£k/MWh.yr) 70 11 East Mids 7.391 0.121 0.021 44.724594 60 12 London 1.921 0.017 0.000 51.870233 44.76 13 Manweb 10.508 0.348 0.180 42.678395 50 41.09 38.80 43.67 36.60 38.11 38.17 34.20 33.52 14 West Mids 7.156 0.392 0.007 45.738925 33.82 40 31.28 27.97 15 North East 7.556 0.364 0.036 42.927953 30 20.46 16 North West 6.265 0.463 0.057 42.828015 20 17 Scots Hydro 4.044 1.393 0.313 40.966038 10 18 Scots Power 7.856 0.470 0.017 40.244453 0 19 South East 7.632 0.097 0.008 49.204313 20 Southern 6.572 0.210 0.044 50.078028 21 South Wales 9.942 1.155 0.055 42.306722 22 South West 19.170 0.117 0.046 48.580421 23 Yorks 6.253 0.476 0.033 42.493827 Distribution Area Value of storage to HV HH metered customers in 2017 DUoS charges for HV HH metered customers effective from 1 st Apr 2017 & TNUoS demand charges effective from 1 st Apr 2016 60 25 TNuoS Demand (£/kW) DUoS Red - Green (p/kWh) 50 20 40 15 30 10 20 5 10 0 0 Distribution Area TNUoS DUoS R-G

On-Site Generation In 2015, Lancaster Uni exported 241 MWh (~1% of demand) Could potentially have reduced spend in 2015 by £17,500 Detailed analysis not possible due to Stephenson Halliday lack of data

Payback Period & NPV of Tesla Powerpack Powerpack costs equate to £417,000 for a 1 MWh, 500 kW system Regular annual savings of £26,000/MWh & 5% discount rate give 33 year discounted payback period in north-west (but 15 year projected life!) In the south-west in 2017, annual savings of £65,000/MWh give 8 year discounted payback period. After 15 years, NPV is £258,000/MWh, giving 13% annual rate of return Tesla Powerpack (May 2016) Technology Li-Ion EOS Aurora advertised at £138,000/MWh, Storage capacity per module 100 kWh 50 kW but 75% round-trip efficiency Peak discharge power per module AC-AC efficiency (2 hour system) 82% AC-AC efficiency (4 hour system) 83% DC-DC efficiency (2 hour system) 91% Incentive schemes in US give >£1.6m/MW DC-DC efficiency (4 hour system) 93% $47,000 Cost per module for electricity storage (up to 50% of project Cost per bi-directional 250 kW inverter $65,000 Cost of cabling & other hardware $2,000+$500/module cost)

Near-Delivery Electricity Trading Investigated value of purchasing on day ahead market, assuming 2 hr discharge at 16:30-18:30 weekdays Nov-Feb, optimal schedule elsewhere… Up to £40,000/MWh.yr in north-west, an increase of £13,000/MWh.yr over a flat commodity price

Other Revenue Streams Several other revenue streams exist for small-/medium-scale storage: Service Response Max. Duration Min. Power Trigger Time Enhanced Frequency 1 s 9 s 3 MW Static frequency point Response Firm Frequency Response 2-10 s 1-2 m 10 MW Static or dynamic frequency (Primary) Firm Frequency Response 30 s 30 m 10 MW Static frequency point (Secondary) Fast Reserve 2 m 15 m 50 MW NG request Short Term Operating Reserve 4 h 2 h 3 MW NG request Curtis M. Overview of the UK Demand Response Market. EPFL Workshop, 11 Sep 2015, University of Reading

Other Revenue Streams Market size and returns (Curtis, 2015): Service Overall DR Capacity Procurement Returns Per Year, Per MW Capacity Per Per Year Method Year (MW) (MW) Enhanced Frequency 200 ?? ??? Tender ??? Response Firm Frequency Response 200-700 ??? Tender £15,000 - £20,000 (Primary) Firm Frequency Response 700-1400 ??? Tender £30,000 - £40,000 (Secondary) Fast Reserve ??? ??? Tender ??? Short Term Operating Reserve 2500-3500 200-700 Tender £20,000 - £30,000 EFR aimed specifically at storage FFR runs 24/7 STOR has 2 daily availability windows (~07:00-14:00 & ~16:00-20:00) Returns based on availability payment & utilisation payment

Conclusions • Savings from reducing network charges: £20 - £70/kWh.yr • South-west highest, north Scotland lowest • Value increased by on-site generation, up to £17.5/kWh.yr extra at Lancaster Uni with 2.35 MW WT & 1.9 MWe CHP, 6 MW max. demand • Additional revenue from near-delivery trading: up to £13/kWh.yr • Payback period with Tesla Powerpack: 8 yrs in south-west; 33 years in north-west

Electricity Storage for Large School of something Enterprises FACULTY OF OTHER Thank you Dr Andrew J. Pimm a.j.pimm@leeds.ac.uk