Distributed Solar

Wal-Mart today had a meeting with Al Gore where they talked about sustainability. Wal-Mart has announced some pretty lofty goals with regards to reducing energy consumption and waste. http://www.walmartfacts.com/FactSheets/Sustainability_Fact_Sheet_FINAL-WM.pdf

Some of the things that they list are things that I have previously said to myself, "why is it that..", so I figured this was as good of a time as any to mention one or two, even at the risk of sounding unoriginal, but hey, I never said every one of my ideas would be original.

Not too long ago, I was flying into a reasonably sized city. As we made our approach, I enjoyed the aerial view, as I always do. However, I was struck by the rediculous amount of flat-roofed buildings of significant size that are in your average town. Big-box retailers like Wal-Mart, Target, Lowes, etc, strip malls, regular malls, warehouses, manufacturing facilities, you name it. All of them with the same general design..low buildings with lots of square footage of flat, usually metal roofs. I thought to myself, "why is it that we don't have solar panels or green roofs on every single one of these buildings?"
If a company the size of Wal-Mart were to cover the roof of every building it had with PV solar panels, there would be literally billions of square feet of otherwise useless space generating free, renewable energy. My guess is that with the most efficient PV panels around, a building of that size would be energy neutral on all but the cloudiest of days, even with an electronics department full of televisions and all of the computers and registers. And if any company on the planet can reduce the price of deploying solar panels due to increasing the scale, it's Wal-Mart.

This would lead to a trickle-down effect, as more businesses did the math and realized that in addition to the brownie points that they'd win with those of us that were concerned about their impact on the environment, it may actually be cost-effective as well.
This is where something like solar power (or wind power, where there's steady wind and a willing community) makes a lot of sense. It's a lot harder to get traction for residential solar because of its cost and payback time, and it's not really viable as a replacement for your local power plant because most houses barely posess enough square footage to generate the proper power to break even.
Commercially, the economies of scale make it a better proposition, especially somewhere like a warehouse, where the vast majority of the space is not actively consuming power at any given time, or at least is consuming much less power per square foot than a home or office building.
Get to a critical mass point of distributed solar deployment, and you could conceivably distribute the load of a region over all of the solar panels with excess capacity, and idle all of the non-renewable power generation until nightfall. Do this on a much larger scale, and couple it with improvements in the national tranmission grid, and you can take advantage of the timezones to use power from sunlight in California to light my kitchen during dinner on the east coast instead of my local power company firing up the coal boiler.

I hope Wal-Mart makes good on its claims. Big business support for alternative energy and sustainable use of resources has a much larger effect overall than all of the early-adopter individuals that are doing everything they can.