These days, solar power is getting nearly as much attention as wind received in recent years.

In the first week of December, the EU Energy Institute was quoted extensively in British and other European media regarding that organization's belief that solar panel costs will drop dramatically and be cost-competitive with fossil-fuel-based energy for half of Europe's homes by 2020 -- notably, cost-competitive without a subsidy.

This new cost competitiveness is a simple reflection of the lifetime expectancy of photovoltaics (PV).

For years, it was assumed that a typical PV lasted 20 years, and financing programs and payback calculations for PV-generated electricity were based on the two-decade lifespan. But recent tests conducted by the Energy Institute -- where PVs are put through a speeded-up aging process via exposure to extremes of heat, cold, and humidity -- have shown that the panels can last much longer.

The tests indicated that over 90 percent of the panels on the market 10 years ago still performed well after 30 years, despite a small drop in performance. And, as Heinz Ossenbrink of the EU Energy Institute noted, 40-year panels are on the way.

So is PV making a big move, so to speak, and will it only be in Europe?

"There is a strong chance that PV energy will be cost-competitive [unsubsidized] with residential retail electricity rates in Western Europe and possibly parts of the U.S. by, or before, 2020," said Rocky Mountain Institute (RMI) researcher Sam Newman. "Recent trends indicate PV energy costs are likely to dip below retail rates in certain U.S. states and southern European markets by 2015 or earlier."

Clearly this technology is on the move. In 2008, China became the world leader in PV production. The Energy Institute estimates (pdf) China might boast as much as 32 percent of worldwide production capacity by 2012.

Module lifespan aside, RMI's researchers think that solar costs will be driven down substantially through changes in the way panels are manufactured, installed and regulated, and how the power from them is used.