Earlier this week, Earth2Tech pointed out 7 Green Ideas That Could Strike Gold & Save the Planet, highlighting green submissions from the Rice Business Plan Competition.  Reading through the list, there are some interesting patterns: three ideas (Ancora Energy, Biogas & Electric, and Sanergy) involve waste-to-energy, and two (Sanergy and Solavicta) would support small-scale, decentralized renewable energy generation.

It's interesting, but hardly surprising, that Sanergy fits in both categories.  Waste-to-energy lends itself naturally to decentralized generation, since (as Alex McFarlane of Harvest Power pointed out at Boston Green Drinks, back in March), no one wants to cart garbage around.  Truck garbage more than 100 - 150 miles, and the energy cost of transportation and processing starts to outweigh the benefit.

Waste-to-energy appears to be the next big wave in the renewable energy sector.  It doesn't have quite the photogenic quality that solar and wind have, but it is capable of generating base power (the garbage is your battery).  Moreover, it kills two birds with one stone, by mitigating the landfill problem while generating renewable energy.  For that reason it has a double effect in reducing global warming: it reduces methane emissions from landfills, while offsetting emissions from dirty energy sources like coal.  It should be interesting to see how this sector develops!

Last week was Intersolar 2009, so I thought I'd devote some space here to a solar energy idea.  For all the talk about thin-film solar, solar-powered cell phones, and so on, solar power is actually a very mature renewable energy source.  The technology is predictable; installation and maintenance are well-understood problems.  The problem is financing.

In order to be cost-effective, solar power projects generally rely on the federal tax credit, which was extended this year in the American Recovery and Reinvestment Act.  Using this credit, developers can effectively knock 30% off the cost of a solar power project.  Combined with state and local incentives, as well as potentially lucrative provisions for selling power back to the local utility, the up-front cost for a solar panel can be effectively off-set by lower electric bills in the future.

However, the federal tax credit isn't available for entities that don't have what's called a "tax appetite", i.e. entities which don't have to pay taxes in the first place.  Consequently, non-profit organizations, schools, and other government buildings are not directly eligible for the federal tax credit.  That is a real problem, because in many cases such entities are precisely the ideal location for a solar project - they have a long-term presence in a single physical location, are responsive to their surrounding community, and have a vested interest in reliably cheap power.

Typically, non-taxable entities with a suitable installation site get around this problem by entering into a power-purchase agreement with a private solar developer with a tax appetite.  The agreemnts are fairly complicated, but the basic idea is that a private entity leases the installation site, installs solar power, takes the federal tax credit, and sells the solar power back to the non-taxable "landlord", at a lower rate than the local utility.

The difficulty with power purchase agreements is that they require a lot of hand-holding and trust, on both sides.  As a developer, it can be difficult to find a suitable landlord. On the other hand, a lot of potentially good solar "landlords" don't take the initiative to go looking for a developer, particulalry if environmental action isn't directly related to their mission.

It might be possible to streamline the process a bit, and to lower the barriers for creating new power purchase agreements.  A lot of the data on municipal buildings, and in some cases non-profit buildings, is readily available in government databases.  Using satellite imagery and GIS systems, these databases could be scoured for entities with good prospective solar installation sites.  A bit more careful cross-referencing with the Database of State Incentives for Renewables and Efficiency, along with local utility rates, could also help streamline some of the intial financing work.

The end result would be a high-quality database of prospective solar installation sites for buildings owned by entities lacking a tax appetite.  Selling database access to solar developers should offset the cost of operations.  Ultimately such a database would reduce the cost of the solar power development process by streamlining power purchase agreements, and would encourage the development of more solar power.