Evaluating The Trade-Offs Between Conventional Electricity Storage And Thermal Storage

Transcription

1 Evaluating The Trade-Offs Between Conventional Electricity Storage And Thermal Storage Presented at the 5th Energy Storage Forum, Rome, Italy Presented by: Jurgen Weiss June 13, 2012 Copyright 2011 The Brattle Group, Inc. 1

2 Agenda One slide about Brattle and myself The universe of storage options beyond electricity storage Some examples of emerging technologies Key economic questions/ trade-offs A personal view on where it might go Conclusions 2

3 One slide about The Brattle Group and myself The Brattle Group Economic consulting and expert firm of 200+ with offices in the US (Cambridge, Washington, San Francisco) and Europe (London, Madrid, Rome) Economics PhDs and wide network of academic affiliates (including some Nobel Prize winners) Economic analysis for regulatory, arbitration and litigation purposes Very strong on electricity and natural gas market issues as well as finance. Jurgen Weiss, PhD. Leads Brattle s climate change practice 15 years of consulting experience (renewables, energy efficiency, storage, market and incentive design) PhD. Business Economics, Harvard University and MBA, Columbia University Native of Stuttgart, Germany (and lived in France) 3

4 Multiple options are emerging to compete with conventional electricity storage Basic Idea: You can store electricity upstream (in a form that allows reconversion into electricity) Batteries, Pumped Hydro, CAES, flywheels downstream (converted into something it will ultimately be used for) Heat Cold Batteries (the kind that definitively don t feed electricity back to the grid) Moves away from traditional focus onto more integrated and decentralized approaches 4

5 Decentralized CHP+S Example #1: Lichtblick Lichtblick is a German company getting some traction Goal of 100,000 jointly- controlled micro-chp plants with heat storage ( swarm power ) totaling 1.9 GW 19 kw power/32 kw heat each 450 units installed so far 90% efficiency combined heat and power Q: What if you don t need all the heat? (in summer, for example) VW engine, but could work with other types as well Costs 20,000, but customers only pay 5,000 5

6 Decentralized CHP+S Example #2: Scandinavian Homes Combines solar hot water with thermal storage for seasonal heat storage No electricity generation, but potentially displaces electricity use Could you combine with a PV system? 6

7 Example #3: Energy Ice Bear Use electricity off-peak to make ice Use ice to provide A/C during peak electricity demand periods Functions like a battery that allows load shifting, but perhaps at lower cost. Ice Energy Ice Bear unit with cooling coil integrated into existing A/C 7

8 Key trade-offs of electricity versus thermal storage Challenge of traditional electricity storage is that already low efficiencies are further reduced Looking at total energy supply chain allows for a wider perspective re total system cost Cost of storage part Cost of power generation Cost of cooling/heating system Total end-to-end efficiency of heat/cool+power perhaps greater Behind-the-meter systems avoid line losses (at least to the extent they are load reducing) CHP systems have high combined efficiency by making use of waste heat from power generation How much of the waste heat is already recovered and used as part of the power generation system? (CCGT, Cogen, macro CHP) Can you always use the heat? 8

9 Some thoughts on where it might go (1) Currently CHP systems limited to climates with substantial heating needs Even there heating in the summer rare, so that total annual efficiency is lower than max efficiency of systems Some progress on the cooling/storage front ice-energy s icebear: in essence a storage device using cheap electricity off-peak to make ice, using the ice during peak times to create air conditioning. Using waste-heat for air conditioning directly (evaporative cooling, absorption chillers) still doesn t store the cold (but perhaps see above; absorption cooling has been used to make ice for a long time) 9

10 Some thoughts on where it might go (2) Seasonal storage remains challenging due to efficiency losses over weeks/months, but heat storage seems most likely (other than storing fuel) For daily cycling, micro-chcp (micro combined heating, cooling and power) promising as extra costs likely not large if it replaces a system at its end-of-life Decentralized approaches allow for optimization at a smaller scale (including addressing distribution level issues) BUT Contractors don t know what to do Limited geographic markets where there is enough heating load throughout the year to reach the full potential Most markets need a mix of heating and cooling technically feasible, but no micro-combination CHP on the market yet Utilities will likely fight this at least to some extent Loss of volume (significant and not fun, even with decoupling or other revenue adjustment mechanisms) 10

11 Thank-you For more information, contact Jurgen Weiss Principal The Brattle Group 11