Cost estimate of electricity produced by TPV

A crucial parameter for the market penetration of TPV is its electricity production cost. In this work a detailed cost estimate is performed for a Si photocell based TPV system, which was developed for electrically self-powered operation of a domestic heating system. The results are compared to a rough estimate of cost of electricity for a projected GaSb based system. For the calculation of the price of electricity, a lifetime of 20 years, an interest rate of 4.25% per year and maintenance costs of 1% of the investment are presumed. To determine the production cost of TPV systems with a power of 12–20 kW, the costs of the TPV components and 100 EUR kW−1el,peak for assembly and miscellaneous were estimated. Alternatively, the system cost for the GaSb system was derived from the cost of the photocells and from the assumption that they account for 35% of the total system cost. The calculation was done for four different TPV scenarios which include a Si based prototype system with existing technology (ηsys = 1.0%), leading to 3000 EUR kW−1el,peak, an optimized Si based system using conventional, available technology (ηsys = 1.5%), leading to 900 EUR kW−1el,peak, a further improved system with future technology (ηsys = 5%), leading to 340 EUR kW−1el,peak and a GaSb based system (ηsys = 12.3% with recuperator), leading to 1900 EUR kW−1el,peak. Thus, prices of electricity from 6 to 25 EURcents kWh−1el (including gas of about 3.5 EURcents kWh−1) were calculated and compared with those of fuel cells (31 EURcents kWh−1) and gas engines (23 EURcents kWh−1).