Electricity Storage for Short Term Power System Service Forskel 10426 Allan Schrøder Pedersen Materials Research Division Risø - DTU
Aim of the project To evaluate and compare technically and economically the available options for using dedicated electricity storage units to provide short term system services at transmission level in the Danish power system. To conclude with recommendations for a second project phase, where one or more demonstration storage systems will be tested experimentally. Project Period: March 2010 - End of 2010 2
Who are the participants: DONG Energy, Aksel Hauge Pedersen Danfoss Silicon Power, Claus A. Petersen Danfoss Ventures, Arno Knöpfli KK Electronics, Henrik Simonsen SEAS-NVE, Kristine Fløche Juelsgård Danish Technological Institute, Anders E. Tønnesen DTU Elektro, Arne Hejde Nielsen DTU MEK, Brian Elmegård Risø DTU, Allan Schrøder Pedersen (project management) The project group aims to combine competences in markets, power supply, power control and physical/chemical insight in storage tecnologies. 3
Ancillary services Are services required for the security and stability of the transmission system and for maintaining the quality of electricity supply Presently, Energinet.dk buys the following ancillary services: DK1 West Denmark Primary reserves - 26 MW Proportional to frequency deviation, 50% 15 s, 100% 30 s, maintain 15 min Secondary reserves (LFC) - 90 MW Manual regulating reserves DK2 East Denmark Frequency controlled operational disturbance reserve - 23 MW Proportional to frequency deviation and completely within 150 s Frequency controlled normal operational reserve 175 MW Manual regulating reserves Black start services Black start services Short circuit power, reactive power and voltage control Short circuit power, reactive power and voltage control 4
Cascading contingency reserve arrangement MW Instantaneous contingency reserve Automatically activated replacement reserve Manually activated replacement reserve Activation Reestablishing Activation Reestablishing 30 s 15 min Request Request +15 min 5
Ancillary services in Denmark today and tomorrow Ancillary services are today provided by thermal power plants and supplementary generators like gas generators fed by natural gas. DoE has estimated that for every gigawatt (GW) of wind capacity added, for example, 17 megawatts (MW) of spinning reserves must also be built to account for the system s variability 6 Boston ExCo 62nd 2008 23-24 Sept
The technologies in focus: Stationary batteries Flywheels Pumped hydro Compressed Air Energy Storage CAES Super capacitors Other technologies 7
Batteries Relatively high electric efficiency (70-85 % not including charging circuit) Very fast response time Capacity decreasing with time depending on use Low energy density (weight and volume) Stationary vanadium flow battery at SYSlab, Risø DTU
Vanadium flow battery at Risø DTU 15 kw, 120 kwh System components: Cell stacks (3 40 cells in total) Electrolyte tanks (2 6500 liter) Balance of plant (pipes, pumps, etc.) (pumps, pipes, etc) Control and communication unit AC/DC power converter Photograph of the vanadium battery at SYSLAB. To the right, the system components are listed
Schematic drawing of a vanadium battery. The aqueous electrolyte is pumped into the fuel cells (here only one cell is depicted) on each side of the cell membrane. The concentration of the different vanadium ions in the two electrolytes leads to an electrochemical potential over the cells. 10
Testing the flow battery at Risø DTU State of Charge as function of time (from April 2008 to August 2009).
Vanadium Battery Battery balancing wind input in SYSlab Experimental studies characterization of battery performance (cell stacks, power converter, auxiliaries, degradation) demonstration and hands on experience balancing of wind power in SYSlab realistic input to model (island systems balancing, grid stabilization, etc)
New batteries underway AltairNano battery cycle life in lab 13
Pumped storage Widely used, EU 40 GW, US 25 GW Round Cycle Efficiency 70-85% Ramping time: 15 sec 1 min Low Energy Density: 1m 3 100 m holds 0.27 kwh Depending on geography: inconvenient and expensive elevated
Green Power Island Designed by GottliebPaludan Architechts Green Power Island Copenhagen: 3,5 km2 artificial island south of Copenhagen
Energy Membrane Forskel 010216 16
Beacon Technical Advantages Fast and more effective than fossil and hydro regulation Available alone without generation 20-year projected life Low operational cost Zero direct carbon emissions vs. fossil fuel generators 9
ISO-NE Pilot Program Empirical Data 11
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..Many thanks for your attention