Advantages and Disadvantages
From Thermal-FluidsPedia
Advantages and Disadvantages Unlike wind, solar, or tidal plants, geothermal power plants can deliver power continuously and thus provide base-load electricity.10 Furthermore, geothermal plants are not vulnerable to weather changes, no storage is needed, and distribution is not an issue. Geothermal reservoirs are, however, limited to specific geographical areas. Depending on the resources and on power demand, geothermal plants can be constructed in any size-- as small as 100 kW (convenient for local grid applications and rural electrification) to many hundreds of megawatts for base-load and load-demand applications and for national grids. Modular plants can be built so that capacity can be added as the need for power increases. Like most renewable energies, direct-use systems require a larger capital investment as compared to traditional systems, but the lack of fuel cost and lower operating expenses offset the initial investment in only a few years. The cost of power production varies greatly from 2.5 to 10 cents per kilowatt-hour, depending on such factors as the size, depth, location, and temperature of the reservoir. As the price of petroleum and other fossil fuels increase, geothermal sources become more competitively priced or even cheaper than fossil plants. The currently installed US capacity of direct-use systems totals to 470 MW, enough energy to heat 40,000 average-sized houses.