New reports explore environmental, winter impact of solar tech

This seems to be the year of solar excitement, so I'm trying to keep some practical perspective on how excited I get about developments in the industry. Along those lines, I've been reading about two new studies that aim to explore some of the long-term implications of software technology.

The first, a joint report produced by the CPV (Concentrator Photovoltaic) Consortium and the Renewable and Appropriate Energy Laboratory at the University of California in Berkeley, looks at the environmental implications of solar technology along two lines: the potential impact of the technology from a materials and disposal standpoint, and the impact of actual installations on the footprint of the land on which they are installed.

Concentrator photovoltaic works by optimizing the amount of solar input that panels receive with technology that essentially follows the sun. The report suggests that the optimal use case for the technology is a high, desert-like area with high solar resources. That said, there are some things to know about CPV technologies, according to the reporter:

• The actual "embodied" greenhouse gas emissions impact of CPV technology is higher than for non-concentrator systems. That's because of the tracking mechanisms that help CPV technology optimize energy generation. This will be minimized with design changes over time.
• Concentrating solar technologies that use ambient air for cooling rather than water can use up to 90 percent less water than those designed for water cooling.
• While CPV technology uses more land space than a non-CPV alternative, the efficiency of the technology means that less overall land will be used if you look at the issue in aggregate. Rooftop photovoltaic installations have the least impact on land use, obviously, because they are being sited on land that has already been "disturbed" by a building.

If you're a solar geek, you'll want to look more closely at the CPV report.

Another analysis that should interest you over time is a joint project of energy data management company AlsoEnergy and the U.S. Department of Energy National Renewable Energy Laboratory. The project is collecting data related to the impact of snow and ice on photovoltaic system performance. The study was conducted at six solar installation sites near Boulder, Colo., over the past two years.

The main finding, so far, is that even with a pitch that helps snow slide off the roof, rooftop solar installations could suffer a wintertime performance loss because of the usual ice-damming that areas associated with heavy snowfall experience on roofs in the winter. This was less of a problem for ground-mounted systems, because the snow could slide off completely.

The research will continue through the 2011 to 2012 winter season; the result will be findings for installers and others looking to minimize the impact of winter weather on solar installations.

Of course, one approach might be to think vertical, as was the case of this Alaska school that installed its solar panels on the side of the building rather than on the roof. It takes the right location to do this, though.