UPDATED July 3rd: BLM says just kidding, they’re going to “continue accepting applications for future potential solar development on the public lands.” (Thanks for the pointer from Brian Dipert.)

The federal government has placed a moratorium on new solar projects on public land administered by the Bureau of Land Management (BLM) while it studies the environmental impact of both photovoltaic and solar thermal installations. The BLM expects the study to take about two years. The affected proposed projects would cover more than one million acres and have the potential to power more than 20 million homes.

Here’s what the feds are concerned about:

• The impact of construction and transmission lines on native vegetation and wildlife, such as the effects of construction on the desert tortoise and Mojave ground squirrel in California.
• Water use: Concentrating solar plants may require water to condense the steam used to power the turbine.
• Reclamation of the area and habitat restoration after the plants reach the end of their 20-30 year lifespan.

Let’s pause and consider the recent call by President Bush to Congress to end the federal ban on offshore drilling. We can start offshore drilling again because oil is too expensive, but we can’t start to build more solar plants for at least 2 years? Because solar installations have such a history of environmental problems compared to offshore oil drilling, I guess. [End of ironic pause.]

This moratorium may help shift future designs to 2 – 10 MWatt municipal solar power plants located close to power users on the periphery of cities. For example, a 2MW municipal solar power plant requires about 10 acres of land to serve a city of 1,000 homes.(see note below)

Here’s a description of the advantages of these relatively small plants from the Nanosolar web site:

“By feeding power directly into the local, medium-voltage distribution grid, [municipal solar power plants] avoid the long-haul, high-voltage transmission grid which is expensive to build and expand, and they also avoid the expense of a substation for down-transforming transmission voltage to municipal voltage. It’s a form of distributed generation but at the wholesale level and it has been determined (using CPUC methodology and data) that there is a locational benefit of about 35% over wholesale power cost. These are real dollars that providers of wholesale distributed power and rate payers can split in a win-win cost advantage.”

My first reaction to the moratorium is to berate the feds – always my default reaction – but through the Law of Unintended Consequences, the moratorium may shift efforts to the more practical and efficient approach of municipal power plants.

Note on solar plant size and efficiency: There’s a discrepancy in solar plant size and efficiency here: According to the BLM the proposed projects, at 1M acres powering 20M homes, imply 1 acre of solar facility per 20 homes. The municipal solar facilities numbers from the Nanosolar web site estimates that 10 acres will power 1,000 homes, or one acre of facility per 100 homes.