How to Mix Beer and Biodiesel: Questions for Sierra Nevada Brewery's CEO

• beer
• alcohol
• biofuel
• alternative energy
• diesel

Popular Mechanics: Why have beer companies led the way in sustainable manufacturing?
Ken Grossman: As a manufacturer who consumes lots of water and energy, we wanted to be a leader in lowering our impact.

PM: How self-sufficient is Sierra Nevada?
KG: We are 100 percent [self-sufficient] or selling back to the grid at sunlight hours. Overall, we're close to 90 percent with fuel cells, solar panels and our biogas compressor. Baseline use for production is about 2.1 to 2.3 megawatts depending on ambient temperature (and the refrigeration load needed at the time). At night needs drop off.

PM: How important is energy efficiency?
KG: Heat exchangers are our main source of efficiency, prewarming our water for the next batch of beer. Economizers sit above the boilers and recapture the flu heat—preheating the water to go into the boilers, and we've just upgraded our boilers with things like frequency control and blowers to better match combustion air with fuel. This is coupled with real-time stack monitors that are fed into the heat exchanger. Combined, we probably increase our efficiency to the high 80s [percent of heat used] from the low 80s.

PM: Have you ever considered going off the grid?
KG: Going off the grid does and doesn't make sense. With things like solar, we'll always be grid-connected. The amount of battery storage is really pretty prohibitive. Most of America needs power from noon to six and it makes sense to feed it back to the grid. Using the grid, watching peak usage and trying to work in harmony with the existing infrastructure will alleviate stress on the grid. Wind power, too, makes sense in certain parts of the country, but not near the brewery, where winds are low.

PM: As you stated earlier, brewing uses a lot of water—how do you factor this into the equation?
KG: We treat all of our own brewing-process water and convert wastewater into methane in a 160,000-gallon anaerobic digester. We go through about 200,000 gallons of wastewater every day.

Sierra Nevada Beer Factory Photo Gallery
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In the last 10 years, we've put in gravel-lined leach pits in the parking areas to avoid sending some water into storm drains, but water shortages are not a major concern here—there is a deep aquifer at the base of the Sierra Nevada.

PM: What about shipping the beer? How do you alleviate that energy cost?
KG: We recently invested several millions of dollars in our own rail facility—a few miles of track off the mainline. We ship all of our malted barley by rail and the rail saves thousands and thousands of truck miles.

But there's always going to be a rail and truck mix. So we are manufacturing biodiesel from ethanol and yeast created by brewing and from cooking oil from our restaurant. This fuel goes to our delivery trucks.

PM: What lessons do you have for non-brewing industries?
KG: Our nation's energy solutions are going to include a whole mix of technologies. We've tried to look at appropriate technologies that make sense, like capturing energy rather than making new energy. I think this holds true for any kind of manufacturing process—anywhere there's a boiler that is used to heat water, there should be heat exchangers and absorption chilling. It's about getting the most out of an energy source. We need both power and heat, so co-generation makes a lot of sense.

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