Power, electric generation thermal

The radioactive wastes associated with nuclear reactors fall into two categories (1) commercial wastes — the result of operating nuclear-powered electric generating facilities and (2) military wastes—the result of reactor operations associated with weapons manufacture, Because the fuel in plutonium production reactors, as required by weapons, is irradiated less than the fuel in commercial power reactors, the military wastes contain fewer fission products and thus are not as active radiologically or thermally. They are nevertheless hazardous and require careful disposal. 

Other is hydroelectric and nuclear electric power, electricity generated for distribution from wood, waste, geothermal, wind, photovoltaic, and solar thermal energy and net imports of electricity and coal coke. h Minus sign indicates exports are greater than imports. 

Fuel Cell Catalysts. Euel cells (qv) are electrochemical devices that convert the chemical energy of a fuel direcdy into electrical and thermal energy. The fuel cell, an environmentally clean method of power generation (qv), is more efficient than most other energy conversion systems. The main by-product is pure water. 

About 10 percent of the district energy systems are part of combined heat and power systems where both electric energy and useful thermal energy are produced. The electric generation capacity of these systems totals about 3,500 MW, about 0.5 percent of... 

Ocean thermal energy conversion (OTEC) power plants generate electricity by exploiting the difference in temperature between warm water at the ocean surface and colder waters found at ocean depths. To effectively capture this solar energy, a temperature difference of 35°F or more between surface waters and water at depths of up to 3,000 feet is required. This situation can be found in most of the tropical and subtropical oceans around the world that are in latitudes between 20 degrees north and 20 degrees south. 

Thermal power plant is more commonly associated with very large central power stations. The capital cost for thermal power plant, in terms of cost per installed kilowatt of electrical generating capacity, rises sharply for outputs of less than some 15 MW. It is for this reason that thermal power plant is not usually considered for industrial applications unless it is the combined cycle or combined heat and power modes. However, for cases where the fuel is of very low cost (for example, a waste product from a process such as wood waste), then the thermal power plant, depending on output, can offer an excellent choice, as its higher initial capital cost can be offset against lower running costs. This section introduces the thermal power cycle for electrical generation only. 

Wind, solar thermal, and photovoltaic power together accounted in 1998 for only about 1% of U.S. electricity generation from renewable sources and only about 0.1% ofall electricity (DOE/EIA 1999a). 

Stationary power is the most mature application for fuel cells. Stationary fuel cell units are used for backup power, power for remote locations, stand-alone power plants for towns and cities, distributed generation for buildings, and cogeneration where excess thermal energy from electricity generation is used for heat. 

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