GM drew on 62.3 MW of renewable power last year, down from 73 MW in 2011 – but at the same time, the company’s scope 1 and 2 carbon emissions intensity fell 2 percent, from 0.9 to 0.88 metric tons of CO2e per vehicle, according to its 2012 sustainability report.
GM’s carbon intensity fell 5.3 percent from 2010 levels. The company is aiming for a 20 percent cut by 2020.
The report goes into some detail about GM’s existing renewable power sources – including, it says 30 MW of solar, more than 20 MW of landfill gas and, at its Brazil plants and over 15 MW of biomass energy from sugar cane – but doesn’t detail which source has disappeared. Also, curiously, the capacities cited for each renewable technology total over 65 MW, even though the company says it has 62.3 MW.
It does offer some explanation for the decline: “Our overall energy consumption dropped during this time period, as a result of activities such as closing the Shreveport, Louisiana, vehicle assembly plant and the steam elimination project at the Orion, Michigan, vehicle assembly plant, which led to the decreased [renewable capacity] number,” the report says.
GM also says its performance on renewable energy remains consistent with its projected glide path towards its 2020 commitment of 125 MW. It is keeping pace by evaluating cogeneration options for using landfill gas, and exploring additional solar power opportunities, including a 3 MW solar project at the Changwon Assembly plant in South Korea, the company says. By the end of 2015, GM expects to double solar output.
GM published its first sustainability report as a re-organized company in January 2012, and followed that with an update last autumn. According to a spokesman, the update allowed the company to catch up to 2011 data, “and enabled a more normalized cadence of reporting going forward.”
Energy, carbon and water metrics in the 2012 report include all manufacturing and non-manufacturing sites. The company adjusted some base year and target figures to reflected divested assets and (in the case of energy) updated heating values.
One frustrating aspect of the publication is how the company has chosen to measure and report its renewable energy use. The report refers to MW as a measure of “renewable energy use,” which it is not. MW is a measure of capacity. KWh would have been a far better way of showing the company’s renewable use. Then there is the issue of the renewable technologies totaling 65 MW, rather than 62.3 MW. GM appears to combine measures of procurement (“we procure more than 15 MW of biomass-generated electricity from sugar cane”) and generation (“three of our facilities combined generate more than 20 MW of renewable energy from landfill gas.”) Perhaps GM does not itself consume all energy generated from the 20 MW of landfill gas? That could account for the discrepancy – but GM does not explain.