CSP for electricity generation: Dish-Stirling system

1. CSP for electricity generation: Dish-Stirling system

2. CSP for electricity generation: Dish-Stirling system

3. CSP for electricity generation: Dish-Stirling system • - A parabolic dish-shaped (e.g., satellite dish) reflector rotates to track the sun. • The reflector concentrates sun radiation onto a receiver. • At the receiver, energy is transferred to hydrogen in a closed loop. • Heated hydrogen (up to 650oC) expands against a piston or turbine producing mechanical power. http://www.volker-quaschning.de/articles/fundamentals2/index.php

4. CSP for electricity generation: Dish-Stirling system

5. CSP for electricity generation: Dish-Stirling system • Heated hydrogen (up to 650oC) expands against a piston or turbine producing mechanical power. • This power is used to run a generator to produce electricity in kilowatts range. • - The power conversion unit is air cooled, so water cooling is not needed. • Up to 20% efficiency is possible, but costly http://www.volker-quaschning.de/articles/fundamentals2/index.php

6. CSP for electricity generation: Dish-Stirling system 300 MW commercial solar thermal power plant in California https://www.mtholyoke.edu/~wang30y/csp/ParabolicDish.html

7. Major solar energy conversion technologies: Solar Photovoltaics (Solar PVs): are arrays of cells containing a semiconductor material that converts solar radiation into direct current (DC) electricity.

8. Solar irradiance PV module Inverter Charge controller Battery AC loads DC loads Stand Alone System Solar PVs PV cell turns sunlight directly into DC electricity. Total of installed PV was more than 16 GW in 2008.

9. Solar PVs When photons (sunlight) hits the semiconductor, an electron springs up and is attracted to the n-type semiconductor. This causes more negative electrons in the n-type semiconductor and more positive electrons in the p-type. Thus a flow of electricity is generated in a process known as the “photovoltaic effect. Commercially available solar cells achieve solar energy to electricity conversion efficiencies of approximately 15%. http://global.kyocera.com/solarexpo/solar_power/mechanism.html

10. Solar PVs How much electricity can we get from solar roof? Roof area (assumed) = 10 m2 (all covered with PV cells) Solar radiation on earth = 2 – 6 kWh/m2/day (from http://www.nrel.gov/docs/fy03osti/34645.pdf) Conversion efficiency = 20% (max in the market) Electricity obtainable = 0.2 x (2 – 6) x 10 kWh/day = 4 – 12 kWh/day = 166 – 500 W = 3 to 8 bulbs of 60 W strength

11. Solar PVs Photovoltaic Power for Rural Homes In Sri Lanka

12. Solar PVs 7W CFL, 12V Electronics, 10Wp Panel 7Ah MF Battery Backup: 3 to 4 hoursSolar Panel Warrantee: 10 yearsLantern Warrantee: 1 year Solar lantern About Rs 2500/=

13. Solar PVs Photovoltaic 'tree'

14. Solar PVs • The Pocking Solar Park is a 10 MWp PV solar power plant. • - started in August 2005 • completed in March 2006 US$87 million sheep are now grazing under and around the 57,912 photovoltaic modules

15. Solar PVs World's largest PV Power Stations - Huanghe Hydropower Golmud Solar Park (China, 200 MW) - Perovo Solar Park (Ukraine, 100 MW), - Sarnia PV Power Plant (Canada, 97 MW) - Montalto di Castro PV Power Station (Italy, 84.2 MW) - Senftenberg Solarpark (Germany, 82 MW) - Finsterwalde Solar Park (Germany, 80.7 MW) - Okhotnykovo Solar Park (Ukraine, 80 MW) (completed in 2010 and 2011)

16. Solar PVs • Large PV Power Stations • in planning / under construction • - Ordos Solar Project (China, 2000 MW) • Barmer, Bikaner, Jaisalmer and Jodhpur Solar Projects (India, 1000 MW each) • Calico Solar Energy Project (USA, 563 MW) • Topaz Solar Farm (USA, 550 MW) • and more….

17. Solar PVs Inorganic Solar Cells 2nd Generation Thin-film Bulk 3rd Generation Materials Silicon Germanium Silicon CIS Amorphous Silicon CIGS Mono-crystalline CdTe Poly-crystalline Nonocrystalline Silicon GaAs Ribbon Light absorbing dyes

18. Solar PVs Inorganic Solar Cells 2nd Generation Thin-film Bulk 3rd Generation Materials Silicon CdTe (cadmium telluride) is easier to deposit and more suitable for large-scale production. China’s 2000 MW PV plant will use this technology. Cd is however toxic. Germanium Silicon CIS Amorphous Silicon CIGS Mono-crystalline CdTe Poly-crystalline Nonocrystalline Silicon GaAs Ribbon Light absorbing dyes

19. Solar PVs Inorganic Solar Cells 2nd Generation Thin-film Bulk 3rd Generation Materials Silicon GaAs (gallium arsenide) is highly toxic and carcinogenic. When ground into very fine particles (wafer-polishing processes), the high surface area enables more reaction with water releasing some arsine and/or dissolved arsenic. Germanium Silicon CIS Amorphous Silicon CIGS Mono-crystalline CdTe Poly-crystalline Nonocrystalline Silicon GaAs Ribbon Light absorbing dyes

20. Solar PVs Inorganic Solar Cells 2nd Generation Thin-film Bulk Processing silica (SiO2) to produce silicon is a very high energy process, and it takes over two years for a conventional solar cell to generate as much energy as was used to make the silicon it contains. Silicon is produced by reacting carbon (charcoal) and silica at a temperature around 1700 deg C. And, 1.5 tonnes of CO2 is emitted for each tonne of silicon (about 98% pure) produced. 3rd Generation Materials Silicon Germanium Silicon CIS Amorphous Silicon CIGS Mono-crystalline CdTe Poly-crystalline Nonocrystalline Silicon GaAs Ribbon Light absorbing dyes

21. Solar PVs Inorganic Solar Cells 2nd Generation Thin-film Germanium is an “un-substitutable” industrial mineral. 75% of germanium is used in optical fibre systems, infrared optics, solar electrical applications, and other speciality glass uses. Germanium gives these glasses their desired optical properties. Germanium use will likely increase with solar-electric power becomes widely available and as optic cables continue to replace traditional copper wire. Bulk 3rd Generation Materials Silicon Germanium Silicon CIS Amorphous Silicon CIGS Mono-crystalline CdTe Poly-crystalline Nonocrystalline Silicon GaAs Ribbon Light absorbing dyes

22. Solar PVs Calculation of United States’ Sustainable Limiting Rate of Germanium Consumption: • Step 1: Virgin material supply limit • The reserve base for germanium in 1999 = 500 Mg • So the virgin material supply limit over the next 50 years • = 500 Mg / 50 years • = 10 Mg/yr Source: Graedel, T.E. and Klee, R.J., 2002. Getting serious about sustainability, Env. Sci. & Tech. 36(4): 523-9

23. Solar PVs Calculation of United States’ Sustainable Limiting Rate of Germanium Consumption: • Step 2: Allocation of virgin material • Average U.S. population over the next 50 years • = 340 million • Equal allocation of germanium among the average U.S. population gives • (10 Mg/yr) / 340 million • = 29 mg / (person.yr) Source: Graedel, T.E. and Klee, R.J., 2002. Getting serious about sustainability, Env. Sci. & Tech. 36(4): 523-9

24. Solar PVs Calculation of United States’ Sustainable Limiting Rate of Germanium Consumption: • Step 3: Regional “re-captureable” resource base • Worldwide germanium production from recycled material • ≈ 25% of the total germanium consumed • Equal allocation of virgin germanium among the average U.S. population therefore becomes 1.25*29 mg / (person.yr) • = 36 mg / (person.yr) • The sustainable limiting rate of germanium consumption in U.S. is thus 36 mg / (person.yr) Source: Graedel, T.E. and Klee, R.J., 2002. Getting serious about sustainability, Env. Sci. & Tech. 36(4): 523-9

25. Solar PVs Calculation of United States’ Sustainable Limiting Rate of Germanium Consumption: • Step 4: Current consumption rate vs. sustainable limiting rate • Germanium consumption in U.S. in 1999 = 28 Mg • Population in U.S. in 1999 = 275 million • So, germanium consumption rate in U.S. in 1999 • = 28 Mg / 275 million = 102 mg / (person.yr) • which is about 2.8 times the sustainable limiting rate of germanium consumption in U.S. Source: Graedel, T.E. and Klee, R.J., 2002. Getting serious about sustainability, Env. Sci. & Tech. 36(4): 523-9

26. Solar Energy • - Solar power systems generate no air pollution during operation. • Environmental, health, and safety issues involve how they are manufactured, installed, and ultimately disposed of. • Energy is required to manufacture and install solar components, and any fossil fuels used for this purpose will generate emissions. • Thus, an important question is how much fossil energy input is required for solar systems. http://www.ucsusa.org/clean_energy/technology_and_impacts/impacts/environmental-impacts-of.html

27. Solar Energy • Materials used in some solar systems can create health and safety hazards for workers and anyone else coming into contact with them. • Manufacturing of PV cells often requires hazardous materials such as arsenic and cadmium. • Even relatively inert silicon, a major material used in solar cells, can be hazardous to workers if it is breathed in as dust. • There is an additional-probably very small-danger that hazardous fumes released from PV modules attached to burning homes or buildings could injure fire fighters. http://www.ucsusa.org/clean_energy/technology_and_impacts/impacts/environmental-impacts-of.html

28. Solar Energy • Large amount of land is required for utility-scale solar power plants (approximately one square kilometer for every 20-60 MW generated). • Disruption of what might have been pristine property • Intensive construction activities and having large parabolic solar panels or mirrors taking up acres of land could displace migration routes and habitat of wildlife, flora and fauna. • New solar installation sites are graded and sprayed with weed control chemicals.  • Humans will be present on a more regular basis driving to the site in vehicles and disposing of trash, etc. http://www.ucsusa.org/clean_energy/technology_and_impacts/impacts/environmental-impacts-of.html

29. Solar Energy • Solar-thermal plants (like most conventional power plants) also require cooling water, which may be costly or scarce in desert areas. • Large central power plants are not the only option for generating energy from sunlight. • Because sunlight is dispersed, small-scale, dispersed applications are a better match to the resource. • They can take advantage of unused space on the roofs of homes and buildings and in urban and industrial lots. • And, in solar building designs, the structure itself acts as the collector, so there is no need for any additional space at all. http://www.ucsusa.org/clean_energy/technology_and_impacts/impacts/environmental-impacts-of.html

30. Solar Energy • CIS Tower, Manchester, England is 118 m skyscraper with a weatherproof cladding (replacing the mosaic tiles) around the tower made up of PV cells (alive & dummy cells). • It generates 21 kW electricity (enough to power 61 average 3-bed houses) and feeds part of it to the national grid. £5.5 million

31. Solar Energy Photovoltaic Power for Rural Homes In Sri Lanka

32. Solar Energy Source: International Energy Outlook 2011

33. Total solar electricity generation projection: Average growth is 10.6% per year Source: International Energy Outlook 2011

34. World electricity generation projection: Source: International Energy Outlook 2011

35. Comparison of Technologies:

36. Comparison of Technologies: Y. Bravo et al. / Solar Energy 86 (2012) 2811–2825