The
Photovoltaic Cell

A solar cell or photovoltaic cell converts sunlight directly into electricity by the photovoltaic effect

The cell is the smallest building block for a solar panel
The solar panel is an assembly of solar cells connected together

Most commercially available solar panels are using first generation cells. Mostly, silicon based wafers, monocrystaline or polycrystaline. These cells are expensive to manufacture for the following reasons:

• high material cost of silicon
• high energy investment in the production process
• labor intense production process

Second generation cells were developed to reduce the production cost. They utilise more cost effective manufacturing techniques, and they are expected to spread into the commercial markets in the next decade. They are mostly based on thin film production process. Early products started to roll into the market in 2008/2009

Cells can be compared by:

• Power generation capability per an area unit (e.g. Watts/square foot)
• Cost of power generated capabilty per an area unit (e.g. Watts/square foot

At present, the second generation efficiency is not as good as the first generation. Therefore to produce the same power the second generation cell is bigger than the first generation cell. The cost per watt of the second generation though is lower than the cost of the first generation cell.
In many situations, where there is enough roof area to accomodate larger area solar panels the cost is the dominant factor and the second generation "wins"

Third generation cells are still in the research phases, there are different ways the research goes. Researchers are trying to achieve comaprable efficiency to first generation cells with production cost similar to the one acheived for the second generation cost

return from photovoltaic cell page to the residential solar power page