CSP-gas hybrid plants: Cost effective and fully dispatchable integration of CSP into the electricity mix

Transcription

1 CSP-gas hybrid plants: Cost effective and fully dispatchable integration of CSP into the electricity mix Erik Zindel Director Marketing CSP (Power Block) Energy Sector Siemens AG 2012 Copyright Siemens AG 2012 All rights Energy reserved Sector

2 Agenda Introduction to CSP Hybrid power plants basic knowledge The rationale behind hybrid power plants Types of CSP/gas Large Integrated Solar Combined Cycles (ISCC) Balanced Hybrids and ISCCs GT augmented Concentrated Solar Power Plants Operational and dispatching considerations Market potential and regulatory issues Economic analysis Conclusion Page 2

3 are Plants with any Combination of more than one energy source/fuel used CSP Technologies Fossil Fuel Types Parabolic Trough Natural gas Solar Tower Coal Concentrated Solar Power (CSP) plant Fossil Fired Power Plant Linear Fresnel This presentation shows only hybrid power plants with CSP (parabolic trough) - gas Biomass Page 3

4 are the most cost efficient and flexible way to include CSP into the electricity grids 2 basic alternatives to produce both solar and gas power: 1 Separate CSP and CCPP plants Advantages of hybrid plants compared to standalone plants Cost advantage: Lower investment costs due to plant synergies (e.g. only one bottoming steam cycle, plant auxiliaries) 2 Hybrid plant Efficiency advantage: The use of a larger steam cycle at higher steam conditions increases the efficiency of the solar fraction Flexibility: Hybrid power plants can offer a higher degree of flexibility and dispatchability than a pure CSP plant, even if no storage solutions are adopted Page 4

5 Three main types of CSP/gas hybrid power plants Large ISCC plant Balanced Hybrid GT Boosted CSP Configuration Conventional large CCPP with a small solar field Hybrid plant with equal split between gas/csp CSP plant with small booster GT Typical power output MW (of which 5-10% solar) MW (of which 30-70% solar) MW (of which 90% solar) Operational modes gas only + hybrid gas only + CSP only + hybrid operation CSP only + hybrid Market Rationale Combined cycle dispatch and reliability characteristics Solar energy sold at peak hours Solar energy compensates for noon CCPP output decay Green messaging to public Maximized green share with utility-like reliability Fully dispatchable plant and highest operational flexibility Additional solar energy or reduced gas consumption during peak hours Fuel arbitrage Make more efficient use of allowable gas fraction in CSP plants Sell gas fraction at combined cycle efficiencies during peak load prices Qualifies for capacity payments Page 5

6 Large Integrated Solar Combined Cycle (ISCC) - low solar/gas fraction - Configuration HTF Oil Fuel gas Exhaust Gas CSP HP steam Air Gas turbine Generator G 3~ Clutch HP steam HRH steam Cold reheat LP steam HP Steam turbine IP LP Single Shaft CCPP configuration with: GT: SGT5-4000F ST: SST-3000 Solar Field HP separator IP drum LP drum Exhaust Condensate pump Parabolic Trough solar field CSP BENSON boiler HRSG Feedwater Feedwater pump Power Output: 451MW (of which 52MW from CSP) Gas ISCC efficiency: 66.3% Page 6

7 Reheater Balanced and fully flexible Hybrids/ISCCs - balanced solar/gas fraction - Gas turbine Configuration G HRSG Super-Heater 2 HP turbine G LP turbine Multi shaft CCPP configuration with: GT: SGT-800 ST: SST-700 Reheater Superheater - Evaporator - Pre heater Super-Heater 1 Evaporator Economizer 2 Condenser Parabolic Trough solar field Storage optional Parabolic Trough Solar Field BENSON Boiler Economizer 1 HP feedwater heater FW pump Deaerator / feedwater storage tank LP feedwater heater Main condensate pump Power Output: 101MW (of which 40MW from CSP) Gas ISCC efficiency: 87% Page 7

8 Reheater Gas augmented CSP Plants - high solar/gas fraction - G Gas turbine Configuration Heat Exchanger BENSON Boiler HP turbine G LP turbine CSP plant boosted with a SGT-800 gas turbine feeding into the HTF cycle Condenser Parabolic Trough Solar Field Superheater - Evaporator - Pre heater HTF main pump HP feedwater heater FW pump Deaerator / feedwater storage tank Main condensate pump LP feedwater heater Parabolic Trough solar field Storage optionally possible Power Output: 215MW (of which 164MW from CSP) Page 8

9 There are two different operational considerations when designing CSP [MW] Solar Booster Concept solar based production CSP produces additional peak power, sold into grid Gas based production Solar energy compensates for loss of CCPP output at higher daytime temperatures noon 24:00 [time of day] [MW] Fuel Saver Concept Power output of plant is kept constant solar based production Solar energy allows gas part to run at part load Gas based production noon 24:00 [time of day] In a twin GT configuration, one GT can be switched off during daytime Page 9

10 Hybrid CSP Plants need project specific design; technical optimization depends on many variables Influencing design factors Gas prices Electricity prices for gas and CSP Subsidies and other incentives for CSP, CO 2 credits Technical Configuration (solar field type, storage, GT technology, number of GTs...) Operational concept: Solar Booster vs. Fuel Saver configuration Operational regime (hours of operation for which fuel, use of of increased hybrid plant flexibility for arbitrage, etc.) Optimization gas/solar fraction split technical configuration (solar field type, number and type of GT, storage options, etc.) thermodynamic cycle operational concept Location (ambient conditions, DNI, etc.) Page 10

11 Potential Market for CSP Main potential markets for gas/csp hybrid plants Potential markets mainly for other types of hybrid plants (CSP with coal, biomass, etc.) Page 11

12 Regulatory/Incentive schemes for CSP Current regulatory environments Required regulatory environment Set up with CSP/PV in mind Legislation set up for conventional CSP/PV plants and Renewable Energy in mind Hybrid plants do not fit into these schemes Advantages of hybrid power plants not honoured Dispatchability Operational flexibility Inflexible revenues (feed-in-tariffs) Must be applicable to hybrid plants as well Consider CSP/gas hybrids specific regulation Solar fraction of hybrids should get same solar support/fit, without subsidizing the fossil part Fair treatment of hybrid power plants Honour free dispatchability of hybrid plants (not possible with fixed Feed-in-Tariffs) Consider and honour value of storage and operational flexibility in the regulation Current regulatory landscapes need to be adapted to cover hybrid power plants Page 12

13 CSP are the most cost efficient way of introducing CSP into the electricity mix LCOE, IRR Results of Economic Evaluation Hybrid plants offer lower costs and a better NPV/IRR than separate CCPP and CSP plants Additional revenue from capacity payments, time-of-day prices and economic benefits of operational flexibility of hybrid plants were not yet factored in The absolute values are highly influenced by multiple parameters, but the key message is valid for all key configurations Project specific tailorization is a must and will maximize the economic benefit of the plant CSP Plant CCPP Plant Separate CSP+ CCPP plants Hybrid plant The incremental costs of the CSP fraction is comparable to that of PV installations but as dispatchable energy and at a much higher rate of operational flexibility Basis for economic analysis: Hybrid CSP gas power plant, medium DNI, 4300h/a (gas operation), developed country Page 13

14 Gas-Solar: Architectural design of a large ISCC plant Page 14

15 Summary and Conclusion Hybrid plants offer better economics than separate CSP and CCPP plants Hybridization offers the most cost effective and efficient feed-in of CSP power into the grid, at the level of large scale PV costs, while maximizing operational flexibility and dispatchability There are many possible configurations that allow for any potential fraction between solar and gas as required by the business case The best configuration will always depend on a variety of factors and will need to be optimized for the specific conditions of the project, the fuel and electricity markets, the location and the business strategy of the operator. Project design, optimization and integration is best done by an experienced EPC contractor. Page 15

16 Thank you very much for your attention! Page 16