It has already proven itself as a fertilizer and building material, and even as a secret ingredient in ancient Egyptian ceramics. It turns out that cow dung – yes, that stinky excrement that also produces the devastating greenhouse gas methane – could also have a bright future as an abundant source of clean electricity.
Few places better encompass this potential future than Bar 20 Dairy, a dairy farm in Kerman, California that uses methane from cow manure to generate clean electricity with nearly zero carbon emissions. It’s the first dairy farm in the United States to power its own clean energy “microgrid” using biogas, and it could be a tantalizing sign of what the future of green energy for companies with access to lots of methane.
Technology is not that difficult to grasp. Manure and sewage from the farm’s approximately 7,000 cows are hauled and sieved into a 25 million gallon rectangular pit in the ground called a digester. The liquid sits for about 30 days while the methane gas rises to the top of the closed digester. The gas is then routed to a skid shifter, which separates the methane from hydrogen sulphide and other impurities. Finally, the methane is routed to fuel cells which harness it to produce electricity with little or no greenhouse gas emissions.
“This is where Silicon Valley meets Central Valley,” said N. Ross Buckenham, CEO of California Bioenergy, a company that operates and builds manure digesters, including the one used by Bar 20 Dairy.
Generating electricity from cow poop (or other forms of agricultural waste like pig manure) isn’t an entirely new concept. For at least 15 years now, dairy farms from Vermont to Wisconsin have engaged in this type of small-scale bioenergy production, producing enough electricity to power a few hundred homes, and certainly more than enough to run a big farm.
The problem is that most of these places use a combustion engine to run the processes that actually produce electricity. The ecological benefits that come from finding a new use for the waste are essentially wiped out by the greenhouse gases that these engines pump into the air.
This is where fuel cells help out, because they don’t release carbon dioxide as a byproduct when performing methane-electricity reactions. Bar 20 Dairy uses solid oxide fuel cells made by San Jose-based Bloom Energy. They consist of an anode, cathode and electrolyte sandwiched between two interconnected plates. When methane flows through the anode side and air passes through the cathode side, it causes a chemical reaction in the electrons that produces electricity, with virtually no carbon dioxide byproduct.
The result is a clean, self-contained energy microgrid: something Bar 20 Dairy’s Steve Sheheady and his family have been trying to establish for years.
Sheheady, whose grandfather started Bar 20 Dairy, told The Daily Beast that the farm’s micro-grid (reinforced by solar panels) was working better than expected. The fuel cell system, which started operating in October, is expected to produce about 8.5 million kilowatt hours of electricity annually, which is equivalent to powering more than 750 homes, according to Bloom. Currently, the farm produces more energy than it can use. According to Sheheady, excess power is fed back into the local utility grid and used to charge electric cars.
“We used to joke that it would be funny if we could make more money from poo than milk,” Sheheady said. “And now we’re basically here.”
Farms, private companies, healthcare facilities and college campuses are all spending millions to jump on the microgrid bandwagon, lured by the prospect of lowering their energy costs and less reliance on local utilities ( who have struggled with chronic power outages due to disasters and aging infrastructure). And it’s a global phenomenon: Market intelligence firm Guidehouse Insights estimates that spending on microgrid technology and equipment will reach $110.5 billion worldwide by 2030. , microgrids are especially useful for groups operating in states like California, Hawaii, Massachusetts, and New York. , where electricity prices have exploded.
And of course, the slow movement of world governments to address climate change means that private parties are ready to forge ahead on their own to find clean, sustainable sources of energy.
“This is where Silicon Valley meets Central Valley.”
This is especially true in California, which has been pushing industries like agriculture to reduce greenhouse gas emissions since 2006. Although carbon dioxide emissions grab the headlines, methane is 80 times worse for the global warming over a 20-year period than carbon dioxide. About 40% of all methane emissions come from the agricultural sector.
Bloom’s fuel cell facilities, which were purchased by Home Depot, Morgan Stanley and Caltech, run largely on natural gas, which burns relatively clean but still generates high greenhouse gas emissions. The company is very happy to finally see its technology being used in a clean energy project like Bar 20 Dairy. Sharelynn Moore, executive vice president of Bloom, told The Daily Beast that the company also recently began operating a microgrid project for a Silicon Valley company that obtains methane gas from a nearby landfill. It is also in talks with several waste and water management companies to extract methane from their treatment facilities to turn it into electricity.
“We’re about to really change the way energy is delivered,” Moore said. As more states mandate the use of green electricity from renewables like solar, wind and hydro, Moore hopes the company’s fuel cell servers can help. to close the loop.
However, as with many climate change solutions, high costs will prevent many people from participating in these types of projects. Bar 20 Dairy spent approximately $12.5 million on its fuel cell system and digester. Sheheady said he received a $3 million grant from the state of California and requested a rebate of $2.4 million. The rest came from a bank loan. It helps that Sheheady’s dairy farm is large, as not all farms will necessarily have access to the same means of raising this type of capital.
But with the early success of Bar 20 Dairy’s fuel cell system, several other California dairies are interested in developing their own clean energy microgrids. California Biogas has already heard of several who are looking to build the necessary infrastructure and take independent control of their electricity needs.
“If you stay in the dairy business, you’re not going to get away with just looking after the cows anymore, because the costs are so high,” Sheheady said. “We might be able to save dairy this way.”
Talk about milking a cow for all its worth.
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