Abstract: An apparatus including a white light and first, second, and third filters through which the white light is transmitted is utilized to sequentially irradiate a solar cell. The light impinging upon the solar cell from the first, second, and third filters has first, second, and third "tristimulus" distributions. The resulting first, second, and third electrical output quantities produced by the solar cell are measured and utilized to compute normalized spectral response coefficients by normalizing each of the electrical output quantities with respect to the sum of the three. First, second, and third response differences are obtained by subtracting the first, second, and third response coefficients from first, second and third response coefficients previously obtained from a reference solar cell.

Abstract: A solar simulator includes a lamp array of solar lamps pivotally connected to an array frame. The array frame is rotatably and pivotally mounted on a gantry crane, the elevation and lateral position of which are adjustable relative to the position of a solar collector to be tested. The solar simulator maintains the plane of the lamp array parallel to the plane of the test device for all elevations, lateral positions and rotational positions of the lamp array, and controls tilting of the lamps relative to the array frame to any desired angle of incidence. The solar simulator is operated to control the angle of incidence of radiation received by the solar collector to be tested and to vary the distance from the array of lamps to the solar collector in such a manner that the intensity of received radiation along the surface of the test device is uniform, thereby avoiding undesirable lateral gradients in temperature along the surface of the test device.

Abstract: A solar tracking system is disclosed, utilizing a photovoltaic device, for following the changing solar position. When the sun ceases to be the brightest object in the sky, such as during periods of partial cloud cover, and the system seeks to acquire the brightest spot in preference to the sun, the photovoltaic device is automatically overridden. The override system is clock-driven and moves the tracking system to approximate the solar position so that the sun can be immediately reacquired by the photovoltaic device when the sun re-energizes as the brightest object in the sky.