Concentrated Solar Power. Robert C. Armstrong Deputy Director, MIT Energy Initiative Chevron Professor of Chemical Engineering

Transcription

1 Concentrated Solar Power Robert C. Armstrong Deputy Director, MIT Energy Initiative Chevron Professor of Chemical Engineering 1

2 Outline Introduction CSP technologies Storage Economics Looking forward Conclusions 2

3 Introduction What is it? Basic flow chart Direct normal irradiance Solar Collector Field Heat Exchange Turbine Electrical output Depend on direct solar radiation Daily and seasonal variations Not good with hazy skies Cloud cover intermittency, but storage can compensate Vast resource Dispatchable with storage or hybridization Good for central power generation, but still expensive 3

4 Efficiency of a 100MWe CSP Plant 4

5 Daily and Seasonal Variation* *Nevada Solar One, G. Cohen, IEEE, Las Vegas (2006) 5

6 Estimate of CSP Capacity in US Exclude Areas that have less than 6.75 kwh/m 2 /day annual average direct normal resource Areas with average terrain slope greater than 1% Major urban areas and water features Protected federal lands (wilderness, parks, monuments, etc.) Areas with less than 5 contiguous sq. km. 6

7 CSP Capacity in US Southwest State Available Area (mi 2 ) Capacity (MW) Arizona 19,300 2,467,700 California 6, ,200 Colorado 2, ,900 Nevada 5, ,400 New Mexico 15,200 1,940,000 Texas 1, ,700 Utah 3, ,100 Total 53,900 6,877,000 7

8 World Direct Normal Insolation 8

9 DESERTEC Model DESERTEC WhiteBook (2008). 9

10 Areas Needed for CSP Scenarios DESERTEC WhiteBook (2008). 10

11 Current Technology Parabolic trough systems Linear Fresnel Concentrating dishes Power towers Line focus geometry Point focus geometry 11

12 Parabolic Troughs Solar thermal power plant in the Mojave Desert in Kramer Junction, CA One of nine such plants built in the 1980s to early 1990s. Solar Energy Generating Systems (SEGS) 354 MW installed capacity, making it the largest installation of solar plants of any kind in the world Oil in the receiver tubes collects the concentrated solar energy as heat and is pumped to a power block (in background) for generating electricity. Credit: DOE, EERE 12

13 Power Tower Solar power tower uses an array of tracking reflectors (heliostats) to concentrate light on a central receiver on top of a tower. Less advanced than trough systems but potentially offers higher efficiency and better energy storage capability PS10 solar power tower near Seville, Spain 13

14 Concentrating Dish The concentrator dish collects the energy coming directly from the sun and concentrates it on a small area. Thermal receiver absorbs the concentrated beam of solar energy, converts it to heat, and transfers the heat to the engine/generator. Credit: Sandia National Laboratories 14

15 Value of Thermal Storage in CSP C. Libby, EPRI Report (2009) 15

16 Benefits of Thermal Storage Change CSP from variable resource to dispatchable source Better match with consumer demand Buffer Extend Displace delivery Extended utilization and increased efficiency of power block Greater return on turbine-generator investment Increased annual capacity factor for CSP plant 16

17 Hybrid CSP/Natural Gas Plants Add extra boiler to provide steam when sun is not shining Used at 8 of 9 SEGS plants Modest extra costs: extra boiler plus fuel Gas fired steam turbines generally have a high heat rate (BTUs/kWh) use only for peak demand or for emergencies Couple with existing, base-load, fossil power plant Over size boiler in bottoming cycle Use solar to produce additional steam The first operational ISCC plant is in Yazd, Iran; it is 17 MW and began operation in FPL has fully operational 75MW solar component to a NGCC plant as of March 5,

18 LCOE for Solar in the US Southwest Source: GTM Research, Brett Prior (November 2011) 18

19 Current US CSP Projects 19

20 Impact of TOD Pricing on Profitability PV (no tracking) CSP (with storage) PPA Price ($/kwh) $0.10 $0.10 Avg. TOD Factor 1.2x 1.5x Avg. Revenue ($/kwh) $0.12 $0.15 LCOE ($/kwh) $0.11 $0.12 Avg. Profit ($/kwh) $0.01 $0.03 Equity Investor IRR 10% 20% Source: GTM Research, Brett Prior (November 2011). 20

21 CSP Looking Forward Novel applications Game changing technology Key R&D issues 21

22 Novel Uses for Concentrated Solar Thermal Steam for EOR Chevron southern California (tower) Shell Oman (trough) Couple with desalination Process heat for chemical production and refining Solar fuels Thermal energy for CO 2 reduction and fuel upgrading 22

23 Solar Fuels Aldo Steinfeld, ETH Zurich 23

24 CSPonD Non-Imaging Refractor Lid Lid Heat Extraction Hot Salt to HX Light Reflected From Hillside Heliostat rows to CSPonD System Cold Salt from HX Light Collected Inside Insulated Building With Open Window (Not to scale!) A. Slocum et al., Solar Energy (2011) 24

25 R&D Issues Storage New salt compositions (lower freezing temperature, higher decomposition temperature) Need salt properties under operating conditions: radiative, chemical compatibility, scattering, emission, ) Other high energy density storage approaches, e.g., in the form of chemical energy Seasonal storage, i.e., GWyr storage Higher temperature, more efficient alternatives to the Rankine cycle 25

26 R&D Issues Mirror field Lower cost manufacturing More efficient Engineered surfaces for antifouling in a desert environment Efficient and cheap small-scale power cycles (of any kind) Design and optimization for using CSP for peak power, load following and grid stabilization cogeneration of water and electricity hybridization with fossil fuels accounting for time-variability (hourly and seasonal) 26

27 Summary Relatively low cost, but PV is slightly cheaper now Advantage of CSP is dispatchability Easy implementation of efficient, thermal storage Hybridization with NG Could play a role in facilitating large scale penetration of renewables into grid Potential game-changing systems on horizon Attractive alternative uses for the thermal energy 27

28 But Areas of high DNI (e.g., southwest US, large parts of western China, northern Africa, etc.) not often close to load centers Need major transmission upgrades. Costs? Still too expensive relative to fossil power plants Mirror costs/structures Air cooled condensers Appears to be limited to centralized power Stirling dish engines may be exception TBD Terrajoule 300KW for irrigation market 28

29 Questions? 29

30 Projected LCOE for Different Technologies Source: GTM Research, Brett Prior (November 2011) 30

31 TOD Pricing for PV (No Tracking) Source: GTM Research 31

32 TOD Pricing for CSP with Storage Source: GTM Research 32

33 Concentrated Solar Energy for Thermochemistry and Process Heat IEA (2010) 33

34 34

35 DESERTEC WhiteBook (2008). 35

36 Current US CSP Projects 36

37 Current US CSP Projects 37

38 Recently Cancelled CSP Projects 38

39 Current US CSP Projects 39

40 MIT Concentrated Solar Power on Demand (CSPonD) A. Slocum, J. Buongiorno, C. W. Forsberg, T. McKrell, A. Mitsos, J. Nave, D. Codd, A. Ghobeity, C. J. Noone, S. Passerini, F. Rojas, Concentrated Solar Power on Demand, Solar Energy (2011) 40