Sunny Beer

MillerCoors is brewing up some green beer, but not the artificially colored stuff that you see around St Patrick’s Day - I’m talking about beer made with green energy. The company recently installed a 3.2 megawatt photovoltaic array - the largest PV array at any US brewery - at its Irwindale CA brewery. The array's 10,000 solar panels should generate more than 5.5 GWh of clean electricity every year, enough to brew over 168 million bottles of beer. That’s a lotta Super Bowl parties!

^{Image courtesy of Solar City}

Biogas from Wastewater

In addition to all that carbon-free electricity, the brewery also converts wastewater into biogas that fuels a pair of 500 kilowatt generators, bringing the on-site electric generating capacity to over 4 MW. As part of its long-term sustainability plan, MillerCoors has already reduced its water and energy consumption by over 30% over the past five years; the Irwindale solar array will make that number even better. On-site generation satisfies up to 40% of the brewery’s total electric demand, and it doesn’t just save the company money - it also reduces the load on the already overburdened electric grid in southern California. Green beer means fewer brownouts. Cheers!

What City Makes You Think of Beer?

MillerCoors chose the Irwindale brewery because of the sunny weather in the greater Los Angeles area, a location that has an average of about 5.55 peak sun hours (PSH) per day. That made me wonder how much the same array would produce at a brewery in Milwaukee, the city whose name is almost synonymous with American beer, which gets about 4.5 PSH/day. The Irwindale array faces due south, is tilted at an angle equal to the site’s latitude (to maximize annual production), and doesn’t track the sun. According to PVWatts, a solar estimating tool created by the National Renewable Energy Laboratory, the same array that generates 5.5 GWh/year in southern California would generate about 4.4 GWh/year in Milwaukee Wisconsin. That’s only 19% less energy than its California cousin.*

So while I raise a mug to MillerCoors for getting on the “green” beer bandwagon, I’d like to remind them that solar power is almost as effective in Milwaukee as it is in LA. In fact, Germany gets less annual sunlight than the northern US, yet it generates much of its power through photovoltaics. And I’ve heard they make pretty good beer there...

*If you want to do the calculation yourself, the formula is:
Watt-hours/year = Watts (array size) x PSH/day x 365 days/year * 85% efficiency
PSH takes local weather into account, so it already compensates for cloudy days.