The week is starting out bright for the solar industry as SunPower Corp is saying that it has produced a full-scale, five-inch prototype solar cell with an efficiency of 23.4%, which it claims is a world-record for a large area solar cell.

The company reminded in its statement that it reported improvements of its cell efficiency in the laboratory and in mass production since its first all-back contact solar cell prototype in 2003, and CEO Tom Werner is now saying that this is a step function increase from the company's 22% efficient Gen 2 technology, which has been in mass production since last year.

This level of efficiency is expected to be commercially available in approximately two years, and is expected to reduce system cost by 50% by the year 2012.

In a recent discussion with Applied Material’s CTO Mark Pinto, with announcement like this, it is important to consider that high efficiencies are reached in the lab, on a small sample, so don’t get too excited until that efficiency is reached on production cells.

For an interesting take on efficiency issues, check out this article, “A solar panel on every building,” by EDN contributing editor John Mason.