An economic analysis of a solar total energy system is provided on basic investment analysis principles. Assumptions and simplifications of procedure are stated. Assuming that the technology becomes technologically mature in 1990, the first system built (of the type analysed) is anticipated to have a net present value just over $53 million based on a 25 yr economic lifetime and forecasted values for inflation rate, energy escalation rate, cost of capital, cost of operations, cost of maintenance, depreciation, construction time, costs of gas and electricity, and capital cost. A specific case is analysed. Error and sensitivity analyses are not included.