Everyone loves the idea of taking waste and turning it into something useful. The romantic idea of a truly sustainable cycle continues to capture the imagination of companies working on squeezing power or products from a variety of waste sources, whether it’s agricultural, consumer or industrial waste.
The problem with many processes is that they are still very expensive for what is recovered, and it’s tough to turn a profit on waste-to-energy technology from when the costs of coal and natural gas are relatively low.
FlexEnergy does not have any delusions about the price of natural gas versus the promise of clean energy from waste sources. Instead, the company is combining the two sides of the coin, offering micro turbines or entire power generation systems that can run off everything from natural gas to diluted methane. The company just closed $5 million from Louisiana Sustainability Fund, and it raised $13 million in December from SAIL Capital and RNS Capital.
The secret to FlexEnergy’s sauce is a thermal oxidizer, which is used instead of a combustion cycle to heat the gas up to a temperature that can power the turbine. The temperature is high enough to avoid the creation of volatile organic compounds but low enough to prevent the formation of nitrous oxide. “Combustion is like frying an egg,” said Mike Levin, Director of Government Relations at FlexEnergy, “We’re like poaching an egg.”
The Irvine, Calif.-based company’s process means that the methane that comes off landfills or from farms doesn’t have to be high quality. Also, for customers that have no need to process methane, but just need a micro turbine for a combined heat and power system, they’ve got that too.
FlexEnergy is selling just the turbines, which were developed at Ingersoll Rand (FlexEnergy purchased the micro turbine division from Ingersoll Rand) and have been available for purchase since 2004, to various industries across the U.S., including movie studios, pharmaceutical companies and oil companies.
The company sees tremendous growth opportunities in the oil and gas market. Energy companies like BP have already bought some of the turbines, and the booming CHP market helps support the other nascent side of Flex Energy’s business: methane to electricity.
The Department of Defense has begun testing the company's 250-kilowatt Flex Powerstation generation at Fort Benning, which was the first commercial deployment of the Powerstation. Orange County just announced that the Santiago Canyon landfill will use the Flex Powerstation to generate between 1.5 and 2 megawatts of power from methane that is currently being burned as it comes out of the capped landfill.
At both locations, the methane gas had been burned as it came off of the landfills. At Fort Benning, Levin said the gas coming off was around 20 percent methane. Any less and it usually takes a natural gas additive to even flare the gas.
The technology could also be attractive to gas companies, which release methane in the drilling process and could be captured to run drilling operations. “Out at production sites you have flares, and at the same time you have companies that are trucking in diesel to run diesel generators,” said Levin. “Why not use the flared methane?”
The advantage of the system, said Levin, is that it can take anything that is at least 5 percent methane, far lower than many other systems. In Orange County, the system of eight powerstations is expected to pay for itself in five to six years based on the revenue from the gas, and how much will be saved in fees to monitor and maintain the flare that currently burns the methane at the landfill.
The cost of a 250-kW system is $1 million. Because the system can take low-quality methane, Levin said there are fewer pre-treating costs and the $1 million is for the entire system that will take and process the methane in whatever form it comes in. Although the first two projects are at landfills, Levin noted that only about half of the methane is coming from landfills, with the other half coming from wastewater, agricultural and oil and gas production.
FlexEnergy has more than 100 patents on the system, and it is already thinking of what other uses the thermal oxidizer could have besides running turbines. Even without other applications, there are nearly 2,000 landfills in the U.S. that have no waste-to-energy system -- something that FlexEnergy hopes to change if the technology is proven out by Orange County and the DOD.
“The military has about 100 sites just like Fort Benning,” said Levin. “No longer is a low quality of methane a prohibitive factor.”