The US Environmental Protection Agency’s (EPA) Green Power Partnership has released its new list of the top US on-site generation projects, highlighting distributed generation across sectors including retail, manufacturing, the military and municipal power, reports Richard Baillie.

In its latest quarterly Green Power Partnership ranking, the US EPA shows how on-site generation contributes across several sectors. While Wal-Mart – the leading retailer – heads the list, it shares the top of the list with the manufacturers BMW and Coca-Cola. The US Air Force in fourth place – along with the City of San Francisco in fifth – give further proof of the wide application of on-site power.

The EPA’s listing gathers the most significant on-site projects using renewable energy certificates (RECs), on-site generation and utility green power projects. Together, the Top 20 on-site generators generate and use 500 GWh of distributed renewable power each year.

California-based companies and cities performed especially well. Wal-Mart’s top spot was based on its on-site energy generation in California and Texas. The Golden State cities of San Francisco, San Jose, San Diego, Santa Cruz, and Tulare made the list, as did the Encina Wastewater Authority in Carlsbad, and California-based businesses Google, Adobe Systems, and Safeway.

1. Wal-Mart

Wal-Mart tops the list with 115 GWh of on-site generation. The company has a long-term goal of being supplied by 100% renewable energy. Wal-Mart recently completed its 100th solar installation in California and aims to cover about 75% of its California-based stores by the end of 2013. The installations will provide 20–30% of each facility’s total electric needs.

In California and Massachusetts’s stores, Wal-Mart uses micro-turbines that generate 2–3 kW of electricity each. Wal-Mart also has five utility-scale on-site wind projects in operation or under development in Mexico, the US and the UK, totalling 470 kWh of renewable energy a year, according to its 2012 corporate sustainability report.

2. BMW Manufacturing

In second place, BMW Manufacturing earned a 2003 Green Power Leadership Award for using landfill gas to help power its Spartanburg, South Carolina plant. Four gas turbines generate about 4.3 MW of electricity for the factory and also to supply hot water for its cooling, heating and hot water needs.

3. Coca-Cola

Coca-Cola gets the top three spot for its installation of a landfill-gas-to-energy system, one of the largest biogas projects of its kind in the US, which began operating this spring. The system supplies most of the Atlanta-based facility’s energy needs, including electricity, steam and chilled water, and generates at least 48 GWh annually.

4. US Air Force

The United States Air Force takes fourth place with an energy vision to reduce electric demand through conservation and efficiency, increase supply through alternative energy sources, and create a culture ‘where airmen make energy a consideration in everything they do’.

The Air Force is aggressively seeking renewable energy opportunities on its bases and recently conducted assessments on the resource availability and the economic feasibility of developing renewable resources at 62 installations of which 22 sites are being farther evaluated. In 2011, the Air Force had about 194 renewable energy projects on 71 sites either in operation or under construction.

5. City of San Francisco

In fifth place, the City of San Francisco, California, uses more than 25 GWh annually from its biogas facilities and eight municipal solar installations, which are on facilities including a water pollution control plant, a recycling centre, San Francisco International Airport, and a public library.

The City will soon triple its solar generating capacity from 2.2 MW to over 7 MW with the completion of the Sunset Reservoir facility. San Francisco is also placing solar arrays on other municipal buildings and is considering adding urban wind and ocean power projects to its portfolio. The City also operates more than 3 MW of biogas generation facilities.

6. Kohl’s Department Stores

With more than 1100 stores across 49 states, Kohl’s continues to demonstrate its commitment to sustainable business practices. This year marks the third straight year that Kohl’s has been using 100% renewable energy to meet all of its electricity use, purchasing more than 1.5 TWh in renewable energy certificates (RECs) in 2012 alone.

In 2011, Kohl’s expanded its green power portfolio to include on-site wind power, installing wind turbines at its Corpus Christi, Texas store and Findlay, Ohio, distribution centre. Last year, Kohl’s also activated its first fully owned solar arrays on two store rooftops in Arizona. Together, these rooftops host 3322 solar panels and generate 1.3 GWh of electricity annually. As of April 2012, Kohl’s boasts 124 solar locations, having added 17 locations since April 2011.

7. SC Johnson & Son

In seventh place, SC Johnson & Son SC Johnson is one of the world’s leading manufacturers of household cleaning products and products for home storage, air care, pest control and shoe care. Using innovative sources of green power such as cogeneration, wind power and even a burner/boiler system that converts palm shells, the remaining waste of the palm oil industry, into a fuel source, the company generates 40% of its global electricity from renewable energy sources and has reduced greenhouse gas emissions from its global manufacturing facilities by 26% since 2001.

In 2003, a biogas-powered turbine was installed at Waxdale, the company’s 200,000 m2 facility in Sturtevant, Wisconsin, that uses landfill gas to generate nearly 27 GWh of electricity annually. A second cogeneration turbine was constructed in 2004 to use a combination of landfill and natural gas. Together, these turbines generate the daily baseload of electricity and between half and all the steam needed for the plant’s operations.

8. City of San Jose

As part of its Green Vision, the City is aiming to transition 100% of its electricity to renewable sources by 2022. For municipal facilities, this translates into a goal of about 50 MW of renewable electricity. Current sources of on-site renewable energy include biogas engines at the joint San Jose/Santa Clara Water Pollution Control Plant (WPCP) and solar photovoltaic (PV) panels on various municipal facilities.

Upcoming projects include a fuel cell installation at the WPCP, along with solar installations at additional municipal facilities. By the end of 2010, 2219 solar PV systems with a total capacity of 32.5 MW had been installed in San Jose.

9. City of San Diego

The City operates a gas utilization facility in the Point Loma Waste Water Treatment Plant (PLWWTP), a cogeneration facility powered by wastewater methane gas that generates 4.57 MW of electricity. In addition, PLWWTP employs a hydro facility producing another 1.35 MW of power from the 30-metre drop of treated sewage exiting the plant into the ocean.

Landfill methane gas from digesters at the Metro Biosolids Center (MBC) fed by the City-operated Miramar Landfill is captured to produce 6.4 MW of electricity. Following the success of the MBC, the North City Water Reclamation Plant was built to produce 3.8 MW from landfill gas.

The City generates more than 125 GWh of renewable power on an annual basis but only maintains REC ownership on 20.3 GWh because of incentive and tax policies that existed when the projects were developed. About half of the 10.2 MW produced at the wastewater treatment plants is used on site. The City has 15 PV systems installed throughout the region on City-owned facilities capable of producing 2 MW.

For further information about the EPA’s Green Power Partnership and the ranking system, please visit: