Listen to the commentary
Real Audio : MP3 download
Have you ever entertained the idea of generating electricity at home with solar panels on your roof? If so, now may be the time to act. That’s the conclusion Phil Krein reached recently, anyway. He’s a long-time resident of central Champaign and a professor in the U of I Department of Electrical and Computer Engineering, a guy who knows this stuff as well as anyone around.
Why now? Previously, says Krein, installing solar panels
was a job that required either a knowledgeable, dedicated hobbyist with lots of
time, or a specially trained contractor. But that’s not the case anymore.
The availability of two fairly simple new technologies
has emboldened Krein to go ahead with his own do-it-yourself project. One is a high-quality,
self-sealing screw for mounting the brackets to hold solar panels on a roof.
[Phil Krein on the roof of his garage; one screw in, twenty-three to go. Photo by author.]
The other is a photovoltaic panel that comes with
its own small inverter attached to the back. The inverter converts the direct
current produced by the panel to alternating current, which can be fed into the
grid. That makes the system safe for a nonexpert to work with and easy to
expand. Formerly, most photovoltaic panel setups depended on a single, larger
inverter, which required a more complex electrical setup.
In addition to these technologies, the other
incentive for Krein to go ahead with solar now is the extremely low price of photovoltaic
panels. For comparison, about four years ago the best-priced panels cost more
than $5 per watt, or $1200 for a 240-watt panel, and that was down from $9 per
watt in 2007. The panels Krein just purchased are priced at $1.57 per watt, or
$378 per panel plus $30 each for shipping. (They're AC Unison PM240PA0 panels, which you can see on the list at http://oynot.com/solar-panel-price-list.html.)
He ordered them via the Web on a Monday and they
were delivered to his house three days later.
Krein’s expenses for the project total about
$3280, which breaks down as follows:
$2448 for six solar panels; $540 for the optional
monitoring box that watches their performance; $150 for mounting hardware and
electrical bits and pieces; $50 for a new two-way electric meter; and $80 for
an electrical permit. This doesn’t take
into account the federal tax credit for residential solar projects or state
incentives that can be sought.
In the current phase of the project Krein is
installing six panels. Together they’ll produce about 2400 kilowatt-hours of
electricity over the course of a year. That’s about 30 percent of what his
family uses, and, at current prices, a savings of roughly $20 a month. That may
not sound like much, and Krein’s project may take ten years or so to pay for
itself, but as he points out, “The warranty is 25 years, so I don’t have to
think about it again until it is time to replace the roof.”
That would already make it a reasonable deal, but
Krein thinks there’s no reason to believe the panels will not continue to
function for far longer—possibly fifty years. You can call that anything you like, but I call it
cheap, non carbon emitting, non air polluting, non water polluting, non land
occupying electricity.
