While large-scale, even utility-scale wind and solar energy schemes dominate the clean energy sector, the use by corporations and public sector bodies of smaller-scale renewable technologies based at their own sites is also important to meeting climate goals. In the US, the adoption of on-site renewables is supported and also well-documented by the Environmental Protection Agency (EPA) under its Green Power Partnership.

Now, in support of President Obama’s Climate Action Plan of a couple of years ago, the Partnership has adopted a challenge to double the use of on-site green power by its partner companies by the end of the decade.
Barack Obama 

The biggest users of on-site renewable power in the US are well-known. Wal-Mart generated and used a huge 160 GWh last year, although this represented just 8% of its total electricity use. Apple used 110 GWh, representing 17% of its total electricity use, while the Department of Energy – no doubt in an effort to ‘walk the walk’ – also generated 110 GWh, but this represented just 2% of its power usage. These three very different entities used a combination of solar, wind and biomass/biogas technologies.

Perhaps surprisingly, two car manufacturers – BMW and General Motors – were the next-biggest consumers, both employing landfill gas-to-power plants to produce around 40% of the electricity needs at individual manufacturing plants in the US.

Other organisations generated higher proportions of their electricity usage on-site – Cooper Farms generated 81% through on-site wind power, while the Encina Wastewater Authority reached 82% using its own biogas resources. Most impressively, Yolo County in California generated one-and-a-half times its electricity needs from 7 MW of solar power installations.

Now the EPA expects Wal-Mart and others to double the overall total to 2 TWh by the end of the decade.

The EPA also encourages the use of CHP and earlier this month reached out to the building industry with new guidance for architects and engineers on how CHP can be used to gain points under the US green building certification program: Leadership in Energy & Environmental Design (LEED). CHP’s efficiency and cost saving benefits can greatly contribute to a project’s ability to earn points under LEED. As can on-site renewable generating plant.