Estimated Solar System Costs

In determining the costs of solar power plants, one must consider the following factors and components (1) the value of the land used, (2) the cost of the collectors, (3) installation costs, (4) operating costs, (5) the cost of money, and (6) government support. The purpose of this book is to show that hard and reliable cost and performance data are not yet available and will be obtained only when full-size demonstration plants are built. 

If the solar power plants are built in locations such as the Mojave Desert or Sahara, the land cost might not be excessive. Some argue that there could even be benefits in having these plants in such areas because of the shade, which the collectors provide, and the jobs, which their installation and maintenance create. 

Although the building of the first solar demonstration plants will require the support of national governments or the United Nations, such support may not continue for long. After the price of carbon emissions is established, the market forces alone are likely to support the building of new renewable 

It is estimated that the installed cost of a 1 gW thermal solar power plant is about 3 billion. The mass production of solar collectors is just beginning, and it is probable that with it will come a substantial drop in collector prices. The cost of a new nuclear power plant, if one includes the waste disposal and decommissioning costs, is about 5 to 6 billion. On average, nuclear plants generate 1 gW of electricity, which is about twice the electricity production of typical fossil power plants. The cost of a 1 gW fossil fuel power plant (two 0.5 gW plants), if carbon-capturing technology is included and if carbon emission charges are also considered, is the same as nuclear plants. 

Therefore, even if an installed solar-hydrogen power plant costs 1 billion more than a regular solar plant, this is still under the costs of state-of-the-art nuclear or fossil power plants of the same size range. If the solar collector cost is estimated at 3,000/kW, the life expectancy of the equipment at 25 years, and the interest on investment at 5%, the unit cost of electricity generated will be about 12tf/kWh. This cost is already competitive with fossil-generated peak electricity costs and even with nonpeak electricity prices in some areas. (In June 2007, in Connecticut in my household, we paid 18.9 /kWh for our electricity.) 

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Some noteworthy similarities exist between wind energy systems and CPV systems.9 They both employ relatively common materials, particularly steel. Wind system costs are typically less than 1 per watt they depend mainly on the cost of steel, whereas flat-plate PV is linked to the availability and cost of expensive semiconductor silicon. But solar concentrator structures are also amenable to an auto-assembly type of production (see Fig. 5), and CPV developers estimate CPV production facility costs are much closer to those of wind systems than to those of flat-plate PV production facilities. In early EPRI cost studies, CPV production facility costs were estimated (on the same costing basis as the crystalline and amorphous silicon facilities) to be about 28 million for a 100 MW per year installation—about one-quarter the cost of the conventional silicon PV facilities.10 These lower investment costs can lead to a faster scale-up of manufacturing facilities because investor risk is relatively smaller than the risks entailed in investing in conventional PV production facilities. 

As of this writing (1996), 354 MWe of privately funded, paraboHc-trough electric generating capacity was operating in California. These trough systems operate in a hybrid mode, using natural gas. Collectively they accounted for more than 90% of worldwide solar electric capacity. The cost of these systems fell steadily from 0.24/kWh for the first 14-MW system to an estimated 0.08/kWh for the 80-MW plant installed in 1989 (5). 

A cost analysis was performed in 1991 for a solar detoxification system at Livermore, California, capable of processing an average of 4.4 liters/sec of water with a peak flow of 30 liters/sec. The system would be processing water containing 400 parts per billion (ppb) trichloroethylene to a treated concentration of 5 ppb. Costs were estimated at 16.00 per 1000 gal. Data from the field test using a one-sun mode of operation reduced the estimated cost to roughly 7.00/gal (D12953N, p. 203). 

Another 1991 cost estimate was performed by the Bechtel Corporation for the U.S. Department of Energy s (DOE s) Rocky Flats Plant near Boulder, Colorado. Costs were estimated at 40 per 1000 gal for a system in a site with relatively low solar insolation. The estimate was based on a system with a peak water flow of 6.3 liters/sec and an annual treated volume of 8500 gal. The processing costs were dominated by the cost of a system to treat inorganic components of the water (D12953N, p. 203). 

In 2006, the unit cost of solar electricity from a typical 5 kilowatt (kWp) rooftop system was 30c /kWh in Germany, 19c /kWh in Spain and 22tf/kWh in California. By 2010, Photon Consulting estimates that solar electricity will be produced for 18c /kWh in southern Germany, 12c /kWh in Spain, and 13( / kWh in California. In the United States the typical capital costs including system installation were approximately 3,600/kWp in 2007, with some installations costing only 3,000/kWp. These prices are expected to drop further as government subsidies rise and mass production starts. 

We have made cost analysis for the solar methanol production for the system of Fig. 1. In this analysis, SCOT-solar farm (Solar Concentration Off-Tower central receiver beam-down configuration) is used for solar concentrating system(Fig.2). This solar concentrating system has an economical advantage, since the heavy chemical plant can be installed on the ground. Since the high temperature of 1000-1200°C is obtained by the SCOT-solar farm, chemical plant (or reactor) for solar-assisted coal gasification can be operated. Table 1 shows estimated investment cost... 

In the case of the high construction cost, the solar thermal system is the most economical in higher solar radiation and the hybrid system is the most economical in lower solar radiation. In the case of the low construction cost, the solar photovoltaic system is estimated to be more economical than the other systems in higher solar radiation the hybrid system is still the most economical in lower solar radiation. 

Figure 2 shows the estimated value of Cp when the medium construction cost is assumed. For taking the rise in fuel cost into consideration, the fuel cost, Cp, of 1.5 yen/MJ is assumed in addition to that of 1.0 yen/MJ. The value Cp of the hybrid system becomes higher by 2.82 yen/kWh caused by the rise in Cp by 0.5 yen/MJ. However, the hybrid system keeps its economical advantage in lower solar radiation districts even when the value of Cp is raised to 1.5 yen/MJ. 

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