Agenda 1. EDP Group & HC Energía 2. Conventional approach to storage: price arbitrage 3. New approach: grid services and reserves 4. Redox flow batteries are a promising option 5. Redox2015 project in Hc Energia 6. Conclusions 1
1. EDP Group & HC Energía EDP A reference company in the Iberian market with a strong presence in Brazil and considerable investments in the USA Renewables Electricity Generation capacity Energy generated Energy distributed Energy supplied Gas Energy distributed Energy supplied 23,211 MW 58.393 GWh 80.569 GWh 80.097 GWh 55.585 GWh 33.296 GWh Portugal Spain Brazil 11 Million customers
1. EDP Group & HC Energía Strategic Innovation Priorities in HC Energía Flexible generation Electric Vehicle Energy Storage Smart grids Energy efficiency 3
2. Conventional approach to storage: price arbitrage As a first approach, the economics of energy storage ar assessed by price arbitrage Price arbitrage - charging during off peak hours and discharging at peak hours Transmit power across a capacity constraint during off-peak periods for regeneration later under constrained conditions Charging Period Discharging Periods 4
3. New approach: grid services and reserves Wind power has grown dramaticaly in Spain over the past years Wind power capacity in Spain CCGT capacity in Spain Capacity mix in Spain (%) Wind power has reached the 20 % threshold in Spain
3. New approach: grid services and reserves Now there is a Supply Side Management problem Sometimes wind power grows a lot and has to be disconnected P 6.000 MW 4 h Wind power production in Spain 29.03.2010 Wind power production in Spain 25.02.2010
3. New approach: grid services and reserves Supply peak shaving is the problem now There is a lot of energy wasted but other fuels also suffer Energy lost due to disconnection of wind (MWh) in Spain Thermal units disconnected to allow wind production in Spain
3. New approach: grid services and reserves Peak and off Peak prices are getting closer: the spread for price arbitrage is reducing Spread ( /MWh) in Spain (Peak - Off peak Prices) Days in a year Excess of capacity The number of days with a spread good enough to recover costs is reducing This puts more pressure on the economics of price arbitrage 8
3. New approach: grid services and reserves Threats and opportunities for energy storage Energy storage point of view RES have reduced energy spreads Grid Services Need for quicker and longer reserves Intermittent incontrollable generating capacity 9
3. New approach: grid services and reserves Wind farms are far away from demand: more grids are needed Demand Wind resource 10
3. New approach: grid services and reserves Services to transmission & distribution Investment deferral Grid stability Contingency support Voltage control Frequency control Charge management But all these services deserve a proper retribution 11
3. New approach: grid services and reserves Need for fast and longer reserves 1. Future loads cannot be perfectly predicted 2. Generator ouputs can vary substantially in different time frames 3. Power system equipment can fail without notice Forecast demand Actual demand Operating reserves: real power capability that can be given (upward) or taken (downward) to assist in generation and load balance and frequency control 12
3. New approach: grid services and reserves Reserves are alternative markets Reserve types used in Spain Type of event Up to 15 Minutes Response time Over 15 Minutes Contingency events (Instantaneous failures) Non-event (continious needs) Primary reserve (frequency response) Secundary reserve (regulating reserve) ---- Tertiary reserve (load following reserve) Longer timescale events (forecast errors) --- Deviation management (ramping or slow reserve) Providing reserve capacity can improve storage economics Tertiary and Deviation management are expected to be higher with increasing penetrations of wind power generation 13
4. Redox flow batteries are a promising option Different needs imply different technologies and approaches What do you need storage for? Large-scale electricity storage tecnologies fast power quality applications reserve applications energy management applications improve reliability power quality and uninterrupted power supply (UPS) applications electric power grid stability and switching between energy sources improve profitability load leveling, peak shaving energy discharges from a fraction of a second stored energy is used in minutes rather than seconds or hours energy discharges that last hours High Power Applications Bridging Power Applications High Energy Applications
4. Redox flow batteries are a promising option Power vs Capacity SOURCE: Electricity Storage Association http://www.electricitystorage.org/
4. Redox flow batteries are a promising option But pumping hydro is for the lucky ones Pumping hydro and Compressed Air Energy Storage fall apart from other technologies: Heavy reliance on geology (site dependent) (Portugal, Austria, Switzerland, Slovenia) Massive capital costs and long comissioning periods Mature technology Enviromental issues involved Other technologies are needed to address the storage problem from a distributed & site-independent approach
4. Redox flow batteries are a promising option Capital cost per Energy vs Capital cost per Power SOURCE: Electricity Storage Association http://www.electricitystorage.org/
4. Redox flow batteries are a promising option Redox flow battery scheme Energy in chemical form stored as liquid electrolyte Charge and discharge at electrodes by redox reactions e.g. V 2+ V 3+ + e The electrolyte carries the current between the electrodes (through a membrane) Cell voltage x current density Cell voltage depends on reaction Current density depends on kinetics Many cells make a battery using bipolar stacks
4. Redox flow batteries are a promising option Capacity costs and power costs are independent Redox Flow Batteries show better cost performance for large systems Cost RFB cost benefit Power dependent costs E 1 Energy stored kwh
4. Redox flow batteries are a promising option RFB show more opportunities to bring costs down Tendency of published patents shows better perspective for Redox Flow Batteries. NaS battery VRF battery 20
5. Redox2015 project in HC Energia Consortium and funding Project objective: develop a Vanadium Redox Flow Battery by spanish partners Budget :2,7 M Project length: 27 months (2011-2013) 21
5. Redox2015 project in HC Energia Questions to answer by the project: metrics to evaluate Performance metrics What is the actual efficiency of the battery? How stable is the ciclability in the long run? How does it deteriorate? Calendar and cycle lifes What operation strategies are best adviced to provide ancillary services? What kind of back-up can these batteries provide in case of power cut? 22
5. Redox2015 project in HC Energia Questions to answer by the project: metrics to evaluate Cost metrics What is the capex in /kw and /kwh? How much maintenance and operation costs are expected? What enviromental issues should be taken into consideration in the life cycle and what is their cost impact? 23
5. Redox2015 project in HC Energia Findings so far Battery location study
5. Redox2015 project in HC Energia Findings so far
5. Redox2015 project in HC Energia Findings so far SIMPLE CELL DESIGN 1. Components screening 2. Cell design 3. Charger/Discharger prototipe 4. Flow dynamics modelling 5. Single cell optimizing tests
5. Redox2015 project in HC Energia Findings so far CARBON MATERIALS FOR ELECTRODES Graphite felts modified with metals Peak intensity and reversibility are better than recorded r 25 20 15 10 <I>/mA 5 0 Good performance requires high values of peak intensity and reversibility -5-10 -15-20 0 0,2 0,4 0,6 0,8 Ewe/V
5. Redox2015 project in HC Energia Findings so far OTHER MATERIALS FOR ELECTRODES AND ELECTROLYTE 2. New electrolytes testing 1. Mesoporous carbon based materials Metal salts addition Catalysts improve redox reactions Nanoparticles synthesis (additives) Additives improve current density and ciclyng
5. Redox2015 project in HC Energia Findings so far ION EXCHANGE MEMBRANES 1. Membrane screening 2. Laboratory characterization 3. Single electrochemical cell design,development and test
6. Main Conclusions The bigger differential between peak and off peak prices, the higher added value to energy storage in price arbitrage applications Energy storage for price arbitrage, at the current state of art and current prices, is not competitive But the increase of penetration of wind power implies different conditions to take into account Reserve markets are a good opportunity for energy storage economics Where pumping is not an option, other applications of distributed energy storage are necessary R&D and Demo projects like REDOX2015 are needed to meet performance and cost requirements 30
Thanks for your attention! lsantos@hcenergia.com 31