Solar cell interconnections and the shadow problem

The problem of a regular shadow moving across a terrestially-based solar cell array is discussed. It is shown that by use of a non-regular (pseudo-random) interconnection scheme, it is possible to electrically distribute the impact of the shadow and thus obtain substantially higher average output power. This result applies a fortiori to arrays subjected to dust and appears to apply as well to arrays prone tolocalized damage. Two regular arrays and eight pseudo-random arrays are considered in detail. Each comprises 40 rows of 10 parallel cells each. Improvements of 30-40 per cent are typical, with several more spectacular examples. For regular shadows in a terrestial application, the pseudo-random interconnection scheme gives substantially greater output than the more conventional shunt-diode methodology.