We've watched with increasing interest in recent years as Walmart works to shed its image as a heartless corporate behemoth and makes a legitimate attempt to embrace sustainability. The company has impressed us with its sustainability consortium, progressive recycling policies, and now a thin film solar initiative that will see panels installed on up to 30 Walmart sites in California and Arizona.
The panels will be installed, operated and maintained by SolarCity, and will provide 20% to 30% of the energy needs where they are used. Walmart's panels will also generate up to 22.5 million kilowatt hours of clean energy per year--enough to power 1,750 homes annually--and avoid the production of over 11,650 metric tons of CO2 equivalent each year.
Why thin film? The one micron-thick semiconducters found on thin film solar panels are less energy-intensive to produce than crystalline silicon wafers. They're lightweight, work well in fog and smog, and lie completely flat, so they don't interfere with skylights.
The Environmental Defense Fund, which has been working with Walmart on a number of green initiatives, hopes that the solar panel installation spree bodes well for future renewable energy projects. The EDF explains:
Since the thin film project was first discussed in 2007, other retailers have initiated and implemented a wide variety of solar projects, including some thin film installations. And even when Walmart completes new solar installations on all 30 new sites, they (at last count) have some 8,350 facilities to go. In truth, we’re still waiting for a truly Walmart-sized effort toward achieving the renewable energy goal. But…with more than 2,700 supercenters whose combined roof area alone exceeds 500 million square feet. Walmart still represents extraordinary potential for on-site renewable energy generation and commensurate GHG savings.
Over the next two years, Walmart and the EDF will evaluate the thin film pilot. If all goes well, expect even more solar installations on Walmart roofs all over the country.