Heat losses in Gratzel solar cells

The absorption and reflection spectra of a Gratzel-type solar cell were evaluated in terms of heat losses. Using these experimental data, the temperature distribution inside the solar cell was calculated. The temperature-controlling process in this cell is the heat transfer from the cell to the environment. Assuming the environment temperature of 25 degrees C, the natural air convection leads to the temperature of 46.9 degrees C inside the TiO2 layer. Forced air convection causes the decrease, up to 30.1 degrees C at the wind speed of 10 m s(-1). Variations in the cell dimensions, except the active layer length, have only a small effect on the temperature field, compared to the variations in the heat transfer coefficients. (C) 1999 Elsevier Science B.V. All rights reserved.