Electricity generation capital cost

Modifications of the existing plants to sequestrate and dispose of the CO2 will lead to a reduction in net thermal efficiency and an increase in capital cost both these features will lead to increased cost of electricity generation. Whether these plants will be economic in comparison with conventional plants of higher efficiency and less capital cost will be determined by how much the conventional plants will have to pay in terms of a carbon tax. 

Electric power systems can be thought of as being comprised of three important sectors generation, transmission, and distribution. For most utilities, generation capital equipment costs account for approximately 50 percent of total plant in costs. Generation also accounts for close to 75 percent of total operation and maintenance expense. 

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. 

TES-based systems are usually economically justifiable when the annualized capital and operating costs are less than those for primary generating equipment supplying the same service loads and periods. TES is often installed to reduce initial costs of other plant components and operating costs. Lower initial equipment costs are usually obtained when large durations occur between periods of energy demand. Secondary capital costs may also be lower for TES-based systems. For example, the electrical service equipment size can sometimes be reduced when energy demand is lowered. 

The capital cost of an installed SAL-80 generator, which can treat 1.2 million gallons per day at 1 part per million (ppm) [production of 10 lb free available chlorine (FAC) per day], is 22,347.88. Operating costs for this unit are 15.36 per day, or 5,606 per year, including the costs of salt, electricity, and replacement cells (D157986, p. 6). 

When coal is used in electricity generation, the heat is used to create steam, which is then used to power turbine generators. Approximately 40% of Earth s current electricity production is powered by coal, and the total known deposits recoverable by current technologies are sufficient for at least 300 years of use. Modem coal power plants utilize a variety of techniques to limit the harmfulness of their waste products and to improve the efficiency of burning, although these techniques are not widely implemented in some countries, as they add to the capital cost of the power plant. 

Power plants to burn scrap tires involve large capital investments and annual operating expenses. However, plants located near large supplies of tires can be feasible. A key variable in determining economic feasibility for these plants is the buy-back rate granted by the utility. In areas of the country where the rate is high, such as California and the northeast, power plants are feasible. The buy-back rate is the rate the utilities pay for electricity generated from alternative fuel, and reflects the fuel and other costs avoided by the utility. 

Today, the largest solar power plant in the United States is the 22-year-old thermal plant in California s Mojave Desert, which has a combined total capacity of 354 mW. At Kramer Junction, California, nine solar power plants, each 30 mW or larger, have been in operation for two decades. The yearly insolation in the area is 2,940 kWh/m2. Plant efficiencies range from 10 to 17%, and their capital costs range from 2,500 to 3,500 per kWp The cost of generated electricity from these plants drops as their size increases, and ranges from 10 to 17 /kWh. 

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