May 15, 2009 | 44 If solar power is ever going to take off—and
the world needs it to—photovoltaic cells will have to become a
whole lot cheaper to produce. Making solar cells from silicon,
the most common approach, can be expensive and relatively
inefficient at turning sunlight into electricity. As
semiconductor manufacturer Applied Materials chief technology
officer Mark Pinto told me last year: "With solar, it's all
about cost." But there are signs of improvement, writes Richard
Swanson of SunPower Corp. in this week's Science. Last year,
manufacturers made 5 gigawatts of photovoltaic panels. And some
of these panels required just under six grams of silicon per
watt of power—down from 15 grams at the turn of the century. And
that watt of power now costs around $1.40 to produce compared
with $2 or more in the 1990s. May 13, 2009 | 5 Duke Energy wants
to put a power plant on your house. Over the next year, the
utility plans to spend $50 million to plop a variety of
photovoltaic panels on commercial buildings,