Coal Power Plant Retrofit With Solar
Coal power plants can utilize solar to produce 15%-60% of the electricity. A higher quantity is possible, but requires significantly more modifications to be made to the coal boilers.
Solar Interface
Mirrors, called fresnal reflectors capture the sun’s rays and heat water in the tube above. Steam lines deliver the solar energy to the adjacent coal power plant where existing coal turbines are used to produce an electric current.
The ideal situation for retrofitting a coal power plant with solar includes:
* A large amount of land adjacent to the plant is neededfor solar collectors. Ausra’s fresnal reflector technology requires 2-2.5 acres of land per megawatt compared with 5 acres per megawatt for solar trough systems or 7 acres per megawatt for solar dish engine systems.
* High quantities of solar radiation, such as the American Southwest or the Saharan Desert in Northern Africa, give the solar system a higher return on investment and increase the consistency of the solar energy output.
* Coal power plants that are located in areas with a carbon tax or cap and trade system in place will have a higher return on investment from a solar retrofit.
Coal is a risky business these days and a solar retrofit provides many advantages.
energy costCoal Prices Increasing
Electricity generated from coal has traditionally been much cheaper than electricity from most other sources. This trend is changing. As global demand for coal skyrockets, prices climb.
“There’s a real dilemma facing operators of coal powered plants,” said John O’Donnell, Ausra’s Executive Vice President. “The price of coal has exploded recently and it continues to rise rapidly. Long-term coal contracts are coming in at 4 times the price of the last iteration of the contract.”
Carbon Emissions
Coal is responsible for a staggering 20% of the global carbon emissions. The joker in the deck is the future liability of these emissions and the risk that this creates for owners of coal power plants.
carbon emissions
Australia recently ratified the Kyoto Protocol and will begin trading carbon in about a year. Carbon is likely to trade for $30-$60 per ton, according to John O’Donnell. Ausra’s solar thermal retrofits are cost effective around $30 a ton.
“$30 a ton is $.03 a kilowatt hour [for electricity generated from coal],” said John O’Donnell. “For some of the older coal power plants, you are looking at a 30, 40, or 50% increase in the electricity price all at once and an ongoing uncertain future.”
Bank of America, Chase, and Citigroup are now considering climate change and carbon emissions among the risks in lending to money for electric power plant projects as part of the Carbon Principles. Greenhouse gas emissions are very likely to have a financial cost attached to it in many countries, but exactly how much is anyone’s guess.
Solar Technology is Available Today
Although solar is evolving rapidly, it is available and ready to be implemented today. Ten solar thermal power plants have been operating in California’s Mojave Desert since the 1980’s, with a capacity of 354 megawatts of electricity. Solar technology has proven itself reliable for decades.
Carbon sequestration, which is another option for coal plants to reduce carbon emissions, is still being developed and is not ready to be implemented right away. Sequestration technology is also very expensive and doesn’t remove mercury and other contaminants from the plant emissions.
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