ABSTRACT:
To analyze the economic feasibility of small solar thermal electric power systems, it is important to determine the cost of electrical generation by conventional sources in the 1985-2000 period. To obtain planning information relating to the generation of electric power, nine electric utilities located in high insolation areas of California, Arizona, New Mexico and Texas were surveyed and visited. Information was obtained on present capabilities, plans for future generation and transmission, environmental constraints, present and anticipated water availability, reserve requirements, costs, and reliability. These utilities plan to double their installed generating capacity by 1995. However, the types of new energy sources vary with specific utilities. For example, in Arizona and New Mexico the utilities will rely on new mine-mouth coal plants located in northern Arizona and New Mexico, and on a massive 5-unit 6500 MW nuclear plant near Phoenix. Transmission lines of 200 to 600 miles in length will transmit the power to the load centers. On the other hand, three California utilities plan to double their generation resources by relying on oil and geothermal sources. They also expressed interest in sharing ownership in large coal or nuclear plants if and when they are built in the Southwestern United States. Transmission lines for Southern California utilities are generally less than 100 miles long.

In the Southwest U.S., the energy cost from these additions to the present systems will depend upon numerous factors. Estimates of electric power costs were determined for a variety of scenarios including investor-owned and municipal utility operation; startup dates of 1986, 1995 and 2000; range of fuel prices; various fossil and nuclear technologies; time delays in constructing plants; plant capacity factors of 0.3 and 0.6; and fuel escalation rates of 1% and 2% above a 6% inflation rate. Energy costs in the 1985-2000 period were computed as a function of fuel prices. Using five independent fuel price forecasts, the energy costs range from 50 to 100 mills/kWh for baseload plants and 70 to 200 mills/kWh for intermediate load plants (1978$).

In addition to costs, other factors need to be considered in determining the rate at which small power systems can be expected to be adopted on a broad scale. For example, institutional factors control the rate at which new coal fields, fuel transport systems, and electric power plants can be constructed.

Detailed profiles of the present and future electric generation plans for the nine utilities were developed. The study included a summary of electricity generation of the southwest utility, an overview of present and future alternative fuel availability to utilities, and a description of the methodology used for computing levelized busbar energy costs.