Solar-cell performance with concentrated sunlight

SILICON SOLAR CELLS have been a good source of power for satellites and space probes. Their applicability for future vehicles with larger electric loads seems to be limited by cost and weight. For example, 1 × 2-centimeter (cm) silicon solar cells in the 10 to 13% efficiency range cost about $10 each, or about $350,000 per kw. Conventional panels containing silicon solar cells weigh in the order of 100 pounds per kw.