General Motors became the first automaker to join the Solar Energy Industries Association at last week's PV America East in Philadelphia.
GM already has 30MW of solar installed globally, and has set a target to double that figure by 2015 and bring its total renewable energy capacity to 120MW by 2020.
Rob Threlkeld, renewable energy manager for GM, said that its solar and landfill gas installations had saved the company around $100 million since the early 1990s. “Long-term electricity contracts that can save us money and hedge against increasing rates on the grid,” he said.
In the US, some 2.1% of GM's energy comes from renewables and its solar arrays alone are enough to power 800 homes.
In 2011, GM partnered with utility company DTE Energy to build a 516kw project at its Detroit-Hamtramck Assembly plant. It will generate enough electricity to charge 150 Chevrolet Volts every day and save the company $15,000 a year in reduced energy bills. That year GM also commissioned Constellation Energy to build an array that will save approximately $330,000 during the life of the project.
GM also has a 350kW ground-mount array at GM’s Lake Orion Assembly Plant in Michigan, a 1.8MW rooftop solar array at Toledo Transmission Plant in Ohio and a 1.237MW array on the rooftop of its White Marsh plant in Maryland and a 1MW solar array on the rooftop of its Rancho Cucamonga distribution centre in California.
Last year, SEIA and Vote Solar ranked GM 13th place among corporate consumers of solar electricity, alongside Walmart, Costco, IKEA, Kohl’s, Johnson & Johnson and FedEx.
Threlkeld said: “The strong driving factor is that renewable energy is here, costs have come down significantly, and it's to the point where it's getting to grid parity, which is the driver. As you look at large corporations that are end users we have the ability to drive scale, and that ultimately drives down costs even further and we have the ability to reach a lot of consumers with our end products.”
The company has tended towards poly- and monocrystalline silicon in recent years from the likes of First Solar, although it had used Unisolar's thin film panels in the past. But load-bearing rooftops are not so much of an issue at GM facilities, he said.
“We are pretty agnostic on technology. It's really what works best for the application and the limitations we may have on our facilities. Most of our facilities are 40 to 50 years old and a lot of the equipment is hung from the roof such as conveyor systems. So weight hasn't been a big issue and we've gone more for mono and poly crystalline type panels in the last installations.”
SEIA president and CEO Rhone Resch, said: “Transportation and energy are intrinsically linked, and GM’s decision shows the company’s keen understanding of the synergies between the two industries. We’re looking forward to having GM at the table to discuss how we can provide clean affordable transportation and energy options for the American people.”