EcoVolt is designed to treat large amounts of water with high levels of pollutants. Essentially, microbes consume the pollutants as food and generate electricity that is consumed by other microorganisms that then produce high-quality methane in the process.“As the micro-organisms are doing their job, they’re generating close to 80 percent pure methane—very close to pipeline- grade methane,” Kruger says. “We’re going to capture that methane; run it through a micro-turbine, which basically will burn the methane, turn a turbine and generate electricity. The exhaust runs through a heat exchanger where we will strip the heat out of the exhaust gas and heat our process water.”
Bear Republic anticipates offsetting about 20 percent of its hot-water needs and around 50 percent of its electrical needs with the EcoVolt. In addition, the facility already has installed a 30-kilowatt solar-power system and plans to install another 136-kW system. Combined, the solar panels and EcoVolt should offset close to 100 percent of Bear Republic’s electricity needs.
And, to the delight of the city of Cloverdale, the test EcoVolt unit already is reducing Bear Republic’s biological oxygen demand, or BOD, the measurement of pollutants in wastewater. Once the full-size system is in place, Bear Republic expects to reduce BOD by 80 to 85 percent. “It’s basically taking the water that passes through it and knocking it down to household strength, which the city wastewater plant has a heck of a lot easier time with,” Kruger says.
Although Bear Republic intends to take advantage of the methane produced during wastewater treatment, Kruger says the team currently is considering whether to reuse the treated water once the new system is in place. “The water reuse is sort of a secondary step that we are still kicking around,” he says. “We want to do it but we’re trying to budget for it. The reverse osmosis treatment required for reuse is energy intensive and we are weighing all the options.”
Faith in Technology
Kruger knows implementing EcoVolt seems like a gamble but notes Bear Republic financially is in a position to “put our money where our mouth is”. He adds: “We were fairly confident it was going to work and the demo certainly has panned out. As technology is getting better and cheaper, the rate of return is getting shorter and it just makes sense to do this stuff.”
Bear Republic’s faith in new technology is what helped it garner EPA attention. “Tapping cutting-edge technology for the craft production of 75,000 barrels of beer every year will allow Bear Republic to operate in a more environmentally friendly manner,” said EPA Pacific Southwest Regional Administrator Blumenfeld during the ceremony at Bear Republic’s production brewery. “Innovation provides the double benefit of meeting energy needs and preserving valuable water in short supply due to California’s drought while helping businesses thrive and maintain local jobs.”
“The old business model was that you have cost and you have profit,” Kruger notes. “This really is taking what historically was a cost, or liability, and turning that waste stream into an asset. If we’re not going to be boiled off the face the Earth in the next 100 years, we’re really going to need to figure out how to be more efficient with everything we’re doing. That includes taking what historically had been waste streams and turning them into assets.”
PHOTOS: Bear Republic Brewery, unless noted otherwise