Outlook on Concentrating Solar Power

Transcription

1 Outlook on Concentrating Solar Power Manuel Romero Director Renewable Energy Division CIEMAT Avda. Complutense Madrid Internacional Symposium: Energy and Sustainability Madrid, June 16-17, 2008 Slide 1

2 Outlook on CSP Structure: What does CSP mean?. What do they say about CSP?: Thermodynamics Economy Contexto europeo, regional y mundial Employment Projects under development Role of R&D Solar towers Parabolic troughs Conclusions Slide 2

3 Solar Thermal Power Plants: Ambition of bulk power production Unique integrability into conventional thermal plants With thermal storage or fossil fuel backup solar thermal plants can provide firm capacity without the need of separate backup power plants and without stochastic perturbations of the grid. Solar thermal can supply peak power in summerly heat periods when hydro and wind are scarce. Application to the MW scale. Thermal energy to turbine Thermal energy to turbine From storage HEAT STORAGE Fossil backup OPTICAL To storage CONCENTRATOR Fixed power Solar direct supply RECEIVER Solar time FOSSIL BACKUP W Solar direct supply From storage HOT Fixed power POINT Fossil backup COLD POINT Solar time Slide 3

4 Solar thermal power plants Absorber Tube Absorber tube and reconcentrator Curved mirror Curved mirror Pipe with thermal fluid Parabolic Trough Linear Fresnel Receiver / Engine Reflector Solar Receiver Dish/Engine Heliostats Central Receiver Slide 4

5 Are CSPs Competitive? Wholesale Power Retail Power Small Hydro Solar Photovoltaics Concentrating Solar Biomass Geothermal Wind Power Generation Costs in USD Cents/ kwh Slide 6

6 Market Introduction of Solar Thermal Power Still in the learning curve Solar Generation Cost in EuroCents/kWh R&D and DEMO Phase IEA SSPS, CESA-I R&D Demo Grants SOLAR ONE California Subsidized Markets SOLAR TWO SEGS-I SEGS- II Solar Tres PS10 SEGS III-VII AndaSol 1 SEGS VIII-IX California Premiums 2700kWh/m²a European Subsidized Markets Spanish Premiums 2000 kwh/m² Green Power Markets New Market Entry Next Generation Technology AndaSol N Green Pricing Europe: New market entry Up to 15 GW until 2020 at 5-8 cents/kwh Slide 7

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8 Trans- Mediterranean Renewable Energy Cooperation Ain Beni Mathar Hassi R mel HVDC networks Slide 10

9 CSP worlwide initiatives Source: Abengoa Solar Slide 12

10 CSP worlwide initiatives Slide 13

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12 At the end of 2007 more than 50 CSP projects with about 2150 MW have been registered by the Ministry of Industry 50 MW 50 MW 500 MW 150 MW 350 MW 50 MW 500 MW 500 MW Slide 15

13 Two decades of continuous R&D EUROTROUGH, DISS, INDITEP, EURODISH, SOLAIR, SOLGATE, SOLHYCO, DISTOR Slide 16

14 Impact of innovation on cost reduction Scaling up 15% Production cost R+D 60% Market series 25% Year Slide 17

15 Solar towers today: Early commercial plants ABENGOA SOLAR Solar receiver Steam Drum Steam 40 bar, 250ºC Turbine 11.0MWe» Steam Storage System Heliostat Field Em placem ent Nominal Pow er Tower Height Receiver Technology Receiver Geom etry Helio st at s Thermal Storage Technology Therm al Storage Capacity Steam Cycle Electric Generation Land A nnual Electricity Production Condenser 0,06 bar, 50ºC General Description Sanlúcar M. (Sevilla), Lat 37.4º, Lon 6.23º 11.02M We 100m Saturated Steam Cavity180º, 4 Pannels 5m x 12m 121m2 W ater/steam 15MWh, 50% Rate 40bar 250ºC, 2 Pressures 6.3kV, 50Hz -> 66kV, 50Hz 60Has 23.0GWh Slide 18

16 ABENGOA SOLAR PS10: Heliostats aiming Slide 19

17 ABENGOA SOLAR PS10: Concentrated beam Slide 20

18 ABENGOA SOLAR PS20 and PS10 in Seville (Spain) Slide 21

19 Solar Towers Today: Early commercial plants This project is partially supported by the European Commission (Contract No. NNE5/2001/369), through an European Consortium formed by SENER, CIEMAT, ALSTOM-SIEMENS, SAINT GOBAIN and GHERSA. Slide 22

20 Heliostats: Can innovations lower costs? 30% cost reduction through: Ganged heliostats (>400 m2) Megahelio with carousel (>200 m2) Structurally integrated reflectors (GFRP, hollow extruded polymers) Wireless/PV autonomous heliostat PSA-CIEMAT DLR Abengoa Slide 25

21 Solar receiver: Reliable black-body is the key Temperature (ºC) Volumetric Future developments Trough linear Tubular external Pressure (bar) Tubular cavity Operational range for different solar receivers (Source: A. Kribus) Water-steam need to develop super-heating at high solar flux. Volumetric should improve volumetric effect without penalizing fluid-dynamics and flux profile flexibility. Molten salt should demonstrate long-term availability and increase peak flux Particle receivers and falling films still to pass feasibility phase. All should accumulate operational experience and long-term endurance tests. Slide 26

22 Receivers: More compact, durable and efficient (Efficiency > 85%) Next generation Current Volumetric Molten salt Water-steam Peak flux on aperture (kw/m2) SENER-CIEMAT Slide 27

23 Heat storage: Essential to become dispatchable 2-tank molten salt storage for central receiver plants. Thermocline pebble bed. Sand or mobile solid material for air and particle receivers PCM/ fins storage for saturated water/steam Slide 28

24 Optimizing solar integration Hybrid Solar/fossil Biomass Modularity New cycles Hydrogen 900 C combustor air in receiver solar energy 550 C heat exchanger for cogeneration Project: SOLHYCO recuperator 300 C Slide 29

25 Today's European Trough Technology Diagram of an HTF (Heat Transfer Fluid) Solar Power Plant 395 ºC Oil Superheated Steam (104bar/380ºC) Steam turbine Solar Field Molten salts (hot tank) Condenser Steam generator. Deaerator G 295 ºC Oil Molten salts (cold tank) Oil expansion vessel Reheated Steam 17bar/371ºC Reheater Preheater Slide 30

26 Andasol 1: Under construction Municipality of Aldeire (Granada). Under construction. Start Date: 3Q Infrastructures of evacuation: October Line and SE 66 kv: October Satellite Plant of Gas: October Slide 31

27 Andasol 1: Power block Two storage tanks (ø= 36 m, h=14 m) Storage capacity (h): 50 MW Molten salts: 28,000 Metric Tons/ Melting temperature: 221º C Working range: 291º C - 384º C Slide 32

28 Tomorrow s s Trough Technology Current R+D activities related to Trough Technology New receiver tube designs New support structure designs New solar reflectors New working fluids for the solar field New thermal storage systems Slide 33

29 Current R+D activities related to Trough Technology Current absorbers glass-to-metal weld Glass pin to evacuate the air Vacuum between the glass cover and the steel pipe Glass-to-Metal weld Steel pipe with selective coating 'Getter' to keep and maintain Glass cover the vacuum Expansion bellows Solel design Schott design Slide 34

30 Current R+D activities related to Trough Technology New receiver tube designs New evacuated receiver tube designs with glass-to-metal welds The new receiver tube designs will be very similar to the Schott and SOLEL designs. The main benefit from these new designs will be a larger offer that will ensure reasonable prices Partially-evacuated receiver pipes without glass-to-metal welding Glass-to-metal welding will be replaced by a mechanical seal. The main benefit of these receiver tubes is their superior durability and reliability at a price similar to evacuated receivers Low-cost non-evacuated receiver pipes Glass-to-metal welds will be replaced by a simple seal and the selective coating will be replaced by black thermal paint. Though thermal losses will be higher than in evacuated tubes, the price will be much lower and they could be cost-effective for temperatures up to 300ºC New selective coatings and anti-reflecting films New selective coatings with lower emissivity (ε<0,1 at 400ºC) and better thermal durability have already been developed in laboratories. An industrial process for mass production is still pending The mid-term outcome of current R+D activities related to new receiver tubes will probably be better performance at a slightly lower cost and availability of cheaper products for T< 300ºC Slide 35

31 Current R+D activities related to Trough Technology New working fluids for parabolic-trough collectors Major disadvantages of current HTF technology are: limited maximum steam temperature ( 380ºC) pollution and fire hazards Three new working fluids are being investigated to replace thermal oil and thus overcome its limitations: molten salts direct steam generation gas Slide 36

32 Current R+D activities related to Trough Technology New thermal storage systems There are three R&D lines at present, related to: Sensible heat with molten salt (< 580ºC) Though huge two-tank molten-salt storage systems (1GWht) are being implemented in large parabolictrough solar power plants, this technology has not yet been validated for this size. R&D is still required to investigate the long-term performance and reliability of big systems. Latent heat with molten salt (phase change) (< 320ºC) DSG solar plants require thermal storage systems using phase-change materials (PCM). Several options for PCM storage systems are under study at present (DISTOR project) and a 200kWht prototype is also being evaluated at the PSA. Sensible heat storage with concrete The goal of these R&D activities is to achieve a specific cost of 20 /kwh of capacity. A 2x350 kwh prototype has been tested at the PSA with encouraging results. Two-tank molten-salt storage systems seem to be the best short-to-medium-term option for HTF plants if reliability is confirmed by first operating results. PCM and concrete thermal storage systems seem feasible for DSG plants in the medium to long term. Slide 37

33 Current R+D activities related to Trough Technology New thermal storage systems 200 kwht prototype of PCM storage system designed and manufactured in the DISTOR project 2x350 kwh prototype of concrete storage system installed and tested at the PSA Slide 38

34 CONCLUSIONS CSP: CSP introduces solar energy to high-value markets on high temperature processes, providing high capacity and dispatchability. Solar thermal power plants offer a wide portfolio of integration options with heat storage or hybrid operation for massive production of electricity. First commercial projects already going on in Spain and elsewhere. STPP may integrate North-South Mediterranean electrical networks Slide 39

35 Solar towers: Conclusions Solar towers are nowadays on the verge of commercialization. Early commercial plants (PS10, PS20, Almadén 20 and Solar Tres) will focus further R&D and will provide updated information on costs, efficiencies and O&M. These plants should be used to establish onsite diagnostic methodologies for concentrators and receivers. Heliostats are today mature in terms of performance but still require substantial cost reduction. Receivers need priority work on scaling-up, long-term endurance tests and more compact designs. Better integration into hybrid schemes, biomass and/or higher efficiency cycles is required. Slide 40

36 Conclusions Parabolic troughs: More economical collector designs will be available in short-term with easy-to-implement quality control procedures Receiver pipes designed to meet different requirements will be available in mid term (e.g., non-evacuated low-cost receivers for T<300ºC, semievacuated receivers for T< 400ºC) The use of two-tank molten-salt storage systems in mid-to-long-term still strongly depends on first plant O&M results. PCM and concrete-based thermal storage systems will be available in mid-term (>6 years) The oil of HTF technology will be replaced by other working fluids. The best option can not be found without testing it in a pre-commercial solar plant under real O&M conditions. Slide 41