8. Economic Performance of Solar Gas Turbines

Usually, decision-making about project development is influenced by the costs and benefits over the lifetime of a project. Costs and benefits of a project can be analyzed using several methods, which fall into two groups: (a) methods without time value and (b) those with time value of money. Two widespread indicators of methods without time value are payback period and average rate of return on investment. However, cash flows take place over a certain period of time. Consequently, methods with time value are more relevant, and they include net present value, discounted payback, internal rate of return and levelized cost of energy (LCOE). Some advantages of LCOE over NPV are: (a) the absence of restrictions on project scale, (b) LCOE is independent of energy technologies, and (c) LCOE is applicable even when energy technologies are of different types. Attractive theoretical values of LCOE have been reported (as low as 0.06 US$/kWh) for solar gas turbines (SGTs), which compare very well with LCOE values (0.092-0.095 US$/kWh) for some coal power plants. This indicates that the economic performance of the SGT technology is theoretically approaching parity with conventional thermal power plants.