Electricity Storage Windfarm and Industrial Applications L. Staudt, Centre for Renewable Energy Dundalk Institute of Technology
Presentation Summary Technology overview Windfarm application Industrial application Conclusions
Technology Overview
Technology Overview
Technology Overview
Technology Overview
Technology Overview Economics Profit per transaction (P) value of sales must exceed value of purchases Number of transactions per year (n) As many as possible! Good business: when product of both is maximized (P x n = max)
Technology Overview
Technology Overview
Technology Overview Why flow and NaS batteries (for windfarm and industrial applications)? Flow batteries (and NaS) provide high power and high energy You can easily and independently select both power and energy, as the products are modular They have no special site requirements Will first discuss flow batteries, then NaS
Technology Overview A flow battery is an electrochemical electricity storage device, somewhere between a standard rechargeable battery and a fuel cell The energy is stored (only) in the electrolytes, which can be fully discharged and recharged Power and energy are independent More power: add flow cells More energy: add electrolyte
Technology Overview Basic flow battery schematic
Technology Overview
Technology Overview Moab, Utah 250kW 8 hour installation
Technology Overview Moab, Utah
Technology Overview Tomamae windfarm, Japan 4MW, 1.5 hour flow battery installation
Technology Overview RISO 15kW, 8-hour flow battery
Technology Overview Advantages of flow battery technology Flexible location Good energy density Independent energy and power sizing Thousands of deep charge/discharge cycles (long lifetime) Operate at ambient temperatures Acceptable cycle efficiency Mass market should lead to lower costs Quiet operation
Technology Overview Flow battery concerns Cost Proven reliability Proven efficiency Technology not mature may have surprises Maintaining electrolyte purity (appears OK) Current density can be improved Environmental issues (appears OK) Needs a building Business stability (early days)
Technology Overview NGK Sodium Sulphur battery (not a flow battery)
Technology Overview NGK NaS battery
Technology Overview (NaS) NaS vs. flow battery Longer commercial history Cycle life depends on DOD Better energy density No building required Higher efficiency Lower cost?
Technology Overview Vanadium Redox (VRB) Zinc Bromine (ZBB) Cerium Zinc (Plurion) NaS (NGK) Efficiency 65-75% 60-70% 70-80% 75-85% Lifetime >10,000 cycles >1500 cycles >15,000 cycles ~5000 cycles Cost 4-hour system 8-hour system (w/o building) 1800/kW 2600/kW (w/o building) 1800/kW 2600/kW (w/o building) 1800/kW 2600/kW 1400/kW 2400/kW O&M cost 0.5% of Capex 0.5% of Capex 0.5% of Capex 0.25% of Capex Wind projects Kings Island 200kW/800kWh Tomamae 4MW/6MWh n/a n/a Hachijo Island 400kW/3MWh, many non-wind
Presentation Summary Technology overview Windfarm application Industrial application Conclusions
Windfarm application We created a model that optimally dispatched storage at a 12MW windfarm in the UK (using real UK market prices and windfarm output) Our model determined maximum revenue over the course of a year (purchase cost less sales cost for each half hour) Usually resulted in full charge/discharge each day, but may not e.g. if efficiency is low and price spread is low
Windfarm application A number of cases run for different sizes (MW and MWh) and different efficiencies Base case: 5MW/20MWh with 75% efficiency Gives an optimistic result, due to optimal operation Selectable battery cost: X per MW plus Y per MWh (base case of 1m per MW and 200k per MWh) Adjustable O&M cost (base case of 0.5% of Capex)
Windfarm application Effect of battery energy rating for a 5MW battery system on a 12 MW windfarm
Windfarm application Effect of battery power rating for a 20MWh battery system on a 12 MW windfarm
Windfarm application Base case efficiency and prices achieve a minimum payback period of 35 years Efficiency is very important 60% to 80% efficiency gives a 31 to 54 year payback Halving battery costs gives minimum payback of 17 years for base case Further benefit possible by considering balancing penalties and ancillary services value
Windfarm application Conclusions (windfarm application) Battery costs must decrease substantially Factors that will improve economics: Mass production Improved efficiency Electricity market price spread Value given to ancillary services Technological breakthroughs
Presentation Summary Technology and Application overview Windfarm application Industrial application Conclusions
Dundalk IT storage project In 2005 we installed a large scale commercial wind turbine on the Dundalk IT campus It operates as an autoproducer which results in the reduction in electricity bills Excess electricity generated is exported to grid Electricity deficit is imported from grid Now Dundalk IT is installing a flow battery for primarily research purposes but will also further reduce annual electricity bills
The Campus Wind Turbine at Dundalk Institute of Technology
Dundalk IT storage project Grid (10kV 3 phase) Wind Turbine Circuit Breakers & Metering 10kV 3Phase 690V 3Phase Transformer in base of turbine 690V/10kV SCADA PC To other DkIT transformers (10kV/400V) On site transformer 400V 3 phase 10kV/400V PCS/Battery To DkIT Loads
Dundalk IT storage project Incomer Meter (Grid) Wind Turbine Meter DkIT HV switchroom
kwh Dundalk IT storage project Monthly Data 450000 400000 350000 300000 250000 200000 DkIT consumption with no WTG 150000 100000 WTG P roduction 50000 0 Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec Month Monthly DkIT energy production and consumption
Dundalk IT storage project Monthly Electricty Demand vs Wind Turbine Production (No Storage) 450000 400000 350000 300000 kwh 250000 200000 150000 100000 50000 0 DkIT consumption with no WTG Total WTG Production DkIT consumption with WTG WTG Exported Energy Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec Month
Dundalk IT storage project Following a successful application to Enterprise Ireland for a Capital Equipment grant, Dundalk IT tendered for a 125kW, 500kWh flow battery September 2008 Tender awarded to ZBB (USA) end of 2008 Battery system manufactured and tested February to May 2009 Battery acceptance testing June 2009 Shipped to Dundalk IT August 2009 Installation preparation underway at DkIT
Dundalk IT storage project
PCS Dundalk IT storage project Sea box container DC AC 50kWh 50kWh 50kWh 50kWh 50kWh 50kWh 50kWh 50kWh 50kWh 50kWh Chiller Unit
Dundalk IT storage project Cell stacks
Dundalk IT storage project Power conditioning system during FAT
Dundalk IT storage project Control system display
Dundalk IT storage project Battery foundation
Dundalk IT storage project Battery foundation
Dundalk IT storage project Economics depend on a number of factors including: Electricity tariffs Battery capital costs Battery efficiency Value given to potential utilization of waste heat
Dundalk IT storage project A model was developed by DkIT to evaluate the addition of electricity to the wind turbine It takes half hourly power production and consumption data and MIC for a year and then calculates the annual savings for a given battery rating (kw), capacity (kwh) and efficiency using given electricity tariffs Option to give value to waste heat is included
Dundalk IT storage project
Dundalk IT storage project Various model outcomes Battery capital cost 575,000 Battery efficiency 65% Some Scenarios Value given to Value given Total DkIT Annual savings due exports ( /kwh) to waste heat ( /kwh) Annual Costs ( ) to battery ( ) No storage NA N/A 330,025 N/A 125kW, 500kWh 0.00 0.00 322,156 7,488 125kW, 500kWh 0.057 0.00 290,620 3,597 125kW, 500kWh 0.00 0.04 318,622 11,022 125kW, 500kWh 0.057 0.04 287,086 7,131
Dundalk IT storage project As wind autoproducers operate differently to conventional power generators no value is available at present for: Operating Reserve Reactive Power Generation Black Start Capacity
Dundalk IT storage project Conclusions (industrial application) Battery storage in commercial industrial wind autoproduction applications difficult to justify economically at present Significant reduction in system costs in mass production coupled with increasing electricity prices should make these systems viable with wind autoproduction in the medium term
Dundalk IT storage project However, it is a research project.. The flow battery facility at DkIT will allow: Development and test of control (charge/discharge) algorithms so that the operation of system will maximise economic return This will incorporate a number of factors including, electricity prices, wind and load forecasting Practical experience and assessment of actual performance of this technology
Presentation Summary Technology and Application overview Windfarm application Industrial application Conclusions
Overall conclusions Electricity storage has a bright future Storage will be ubiquitous in electricity grids, becoming The Fourth Element There are presently a number of immature but promising storage technology The technology is not yet generally economic in windfarm and industrial applications Economics will improve with mass production, and with value being given to ancillary services
Questions? larry.staudt@dkit.ie www.credit.ie