The Solar Dish Stirling system is shaped much like large satellite dishes (approximately 37’ in diameter) and covered with curved mirrors. These solar dishes are programmed to always face the sun and focus that energy on a collector in much the same way that a satellite dish focuses radio waves on a tuner. This collector is connected to a Stirling engine which uses the thermal power generated by the focused solar energy to heat liquid hydrogen in a closed-loop system. The expanding hydrogen gas creates a pressure wave on the pistons of the Stirling engine which spins an electric motor creating electricity with no fuel cost or pollution. This technology is referred to as solar thermal or concentrating solar power.
The SES (Stirling Energy Systems) Solar Dish Stirling technology is well beyond the research and development stage, with more than 20 years of recorded operating history. The equipment is well characterized with over 25,000 hours of on-sun time. Since 1984, the Company's solar dish Stirling equipment has held the world's efficiency record for converting solar energy into grid-quality electricity.
In addition to reducing air pollution, how else does a solar Stirling Dish benefit the environment?
Dish Stirling Systems create no adverse environmental consequences. First, with the exception of antifreeze used in the cooling system and the small amount of oil lubricant used in the Stirling engine, there are no toxic chemicals. The hydrogen gas used is sealed inside the engine; although small amounts will escape over time, hydrogen is a non-toxic substance that will diffuse rapidly into the atmosphere. Third, the only fuel used is the sun. Fourth, the only water used is that used to periodically wash the mirrors, only 4.4 gallons per MWh of energy produced (much less than traditional power generation usage). Fifth, since the Stirling engine does not use internal combustion, it is remarkably quiet, emitting less than 66 dB at full load. Sixth, a Stirling solar plant will have no significant biological or cultural/paleontological/geological impacts. The system has a support post structure that is only about 18 inches in diameter, the result being comparable to the planting of a tree. The primary impact, after construction, is to provide shade. Finally, a Dish Stirling solar plant requires only about one acre per 8 systems. Further, the solar plant will normally be located in underutilized land that is far from urban areas.
Is a Stirling Solar Dish new technology?
This is well-established, reliable technology. The SES dish system was initially developed by McDonnell-Douglas in the mid 1980's. Since 1998 SES and Boeing have been under contract with the Department of Energy’s Sandia National Laboratories for a Dish-Engine Critical Components (DECC) program. Phase I of that program incorporated design enhancements to the Stirling Dish System to increase performance and decrease and maintenance costs. Phase II, aimed at system integration and a business and marketing component has been successfully completed. Independent reviews of the DECC program have concluded that there are no serious obstacles to commercialisation of this technology and that this, and other concentrating power technology, could contribute significantly to the U.S. supply of electricity from domestic sources.
What about fuel costs and emissions?
Solar has zero fuel costs and zero emissions.
What geographical areas are best suited for a solar dish farm?
The southwest region of the United States is ideally suited for this. In fact, a solar farm 100 miles by 100 miles could satisfy 100% of the America’s annual electrical needs. Solar technology primarily addresses the peak power demands facing utility companies in the Southwest U.S. and other solar-rich areas.
For more information see http://www.stirlingenergy.com
Showing posts with label CSP. Show all posts
Showing posts with label CSP. Show all posts
Sunday, October 28, 2012
Monday, October 22, 2012
Solar Power from Deserts
Enormous quantities of energy fall as sunlight on the world’s hot deserts and concentrating solar power (CSP) is a proven technology for tapping in to it. CSP is a relatively simple, mature and practical technology that, with the right political and financial impetus, can be brought into play very soon.
CSP plants in the US Deserts have been operating for more than 20 years. Since 1984, the solar dish equipment has held the world's efficiency record for converting solar energy into grid-quality electricity. The CSP plants do not use photovoltaic cells but concentrate the sun’s heat to boil a liquid. This is used to generate electricity. Three types of plants exists.
Power Towers use a large field of sun-tracking mirrors to concentrate sunlight on to a receiver on the top of a low tower, to raise steam and thus generate electricity.
Trough Systems use parabolic trough-shaped mirrors, each one of which focuses light on to a tube containing oil or similar fluid that takes the heat to where it can be used to raise steam and generate electricity.
Dish/Engine Systems uses a large sun tracking mirror with a Stirling engine generator at its focal point to convert heat energy into electricity.
Some detailed projections prepared for the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) show how, even allowing for increases in demand, a combination of CSP with other technologies can enable Europe to cut CO2 emissions from electricity generation by 70% by the year 2050, and phase out nuclear power at the same time
Every year, each square kilometre of hot desert receives solar energy equivalent to 1.5 million barrels of oil. Multiplying by the area of deserts world-wide, this is nearly a thousand times the entire current energy consumption of the world. At the moment, only a small area of desert will need to dedicated to CSP plants to generate enough electricity to power the world.
Are there any problems?
The first thing most people say is that the sun doesn’t shine at night. This is true, but deserts in the US, Africa and Australia all receive sun light at different times. Furthermore, techniques exist for storing the energy in melted salt or other substances. The clean electricity can also be used to produce hydrogen which can be stored.
How do we get the power from the deserts to the UK? It is feasible and economic to transmit electricity to the whole of Europe, the Middle East and North Africa using modern high-voltage DC (HVDC) transmission lines. Average transmission losses over modern high-voltage DC transmission lines (HVDC) are about 3% per 1000 km. In round figures, this means that electricity can be transmitted from North Africa to London with only about 10% loss of power. Since the fuel for CSP is free, any such loss is quite acceptable.
Other benefits
Besides generating electricity, the power plants in deserts could help the economies of Africa and other desert countries. The CSP plants can make use of the waste hot water to desalinate sea water which could have a major impact in alleviating shortages of water throughout the world, a problem that is likely to become increasingly severe with rising global temperatures
Although the area under solar collectors is in shadow, it should still receive a lot of light, quite sufficient for growing plants. Thus land that would otherwise be useless for any kind of cultivation could become very productive. An obvious problem is that plants need water and that is not plentiful in hot deserts. But desalination of sea water is another potential by-product of CSP and this may provide the fresh water that would be needed for CSP horticulture.
The potential of CSP in deserts is so huge that by 2050 the UK could be importing 70 TWh from this source. (1 TWh is enough to power 50 billion x 20 watt low energy light bulbs for an hour)
For more details contact Dr Gerry Wolff on 01248 712962 or by email at gerry@mng.org.uk
The web site can be found at: www.mng.org.uk/green_house
CSP plants in the US Deserts have been operating for more than 20 years. Since 1984, the solar dish equipment has held the world's efficiency record for converting solar energy into grid-quality electricity. The CSP plants do not use photovoltaic cells but concentrate the sun’s heat to boil a liquid. This is used to generate electricity. Three types of plants exists.
Power Towers use a large field of sun-tracking mirrors to concentrate sunlight on to a receiver on the top of a low tower, to raise steam and thus generate electricity.
Trough Systems use parabolic trough-shaped mirrors, each one of which focuses light on to a tube containing oil or similar fluid that takes the heat to where it can be used to raise steam and generate electricity.
Dish/Engine Systems uses a large sun tracking mirror with a Stirling engine generator at its focal point to convert heat energy into electricity.
Some detailed projections prepared for the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) show how, even allowing for increases in demand, a combination of CSP with other technologies can enable Europe to cut CO2 emissions from electricity generation by 70% by the year 2050, and phase out nuclear power at the same time
Every year, each square kilometre of hot desert receives solar energy equivalent to 1.5 million barrels of oil. Multiplying by the area of deserts world-wide, this is nearly a thousand times the entire current energy consumption of the world. At the moment, only a small area of desert will need to dedicated to CSP plants to generate enough electricity to power the world.
Are there any problems?
The first thing most people say is that the sun doesn’t shine at night. This is true, but deserts in the US, Africa and Australia all receive sun light at different times. Furthermore, techniques exist for storing the energy in melted salt or other substances. The clean electricity can also be used to produce hydrogen which can be stored.
How do we get the power from the deserts to the UK? It is feasible and economic to transmit electricity to the whole of Europe, the Middle East and North Africa using modern high-voltage DC (HVDC) transmission lines. Average transmission losses over modern high-voltage DC transmission lines (HVDC) are about 3% per 1000 km. In round figures, this means that electricity can be transmitted from North Africa to London with only about 10% loss of power. Since the fuel for CSP is free, any such loss is quite acceptable.
Other benefits
Besides generating electricity, the power plants in deserts could help the economies of Africa and other desert countries. The CSP plants can make use of the waste hot water to desalinate sea water which could have a major impact in alleviating shortages of water throughout the world, a problem that is likely to become increasingly severe with rising global temperatures
Although the area under solar collectors is in shadow, it should still receive a lot of light, quite sufficient for growing plants. Thus land that would otherwise be useless for any kind of cultivation could become very productive. An obvious problem is that plants need water and that is not plentiful in hot deserts. But desalination of sea water is another potential by-product of CSP and this may provide the fresh water that would be needed for CSP horticulture.
The potential of CSP in deserts is so huge that by 2050 the UK could be importing 70 TWh from this source. (1 TWh is enough to power 50 billion x 20 watt low energy light bulbs for an hour)
For more details contact Dr Gerry Wolff on 01248 712962 or by email at gerry@mng.org.uk
The web site can be found at: www.mng.org.uk/green_house
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