Renewable Natural Gas Looks Promising but Pricey
By Maura Forrest
April 10, 2014
Using manure to heat your home may not sound very appealing, but it’s an idea that’s starting to catch on in British Columbia. Since 2010, gas and electricity retailer FortisBC has partnered with local farms and landfills to supply renewable biomethane to green-minded customers.
On farms, the process works by passing manure and other waste through an anaerobic digester. In the absence of oxygen, bacteria break down the organic matter and release biogas, mostly methane and carbon dioxide. In landfills, methane is given off naturally by the decomposing waste.
Purified biomethane is then injected into natural gas pipelines, where it works as a carbon-neutral energy source in homes and businesses.
“Every molecule of biomethane or renewable natural gas you’re putting into the pipeline, you’re displacing an equal amount of natural gas that comes from fossil sources,” said Scott Gramm, FortisBC’s manager of renewable energy, in a phone interview.
Currently, FortisBC supplies biomethane to more than 6,500 of its 960,000 natural gas customers, who have voluntarily signed up for the service. Those households receive a natural gas blend that is 10 percent biomethane. This year, Gramm hopes to start offering a wider variety of blends.
“If a customer does want to go 100 percent renewable, they will have that option,” he said.
But that option will come with a hefty price tag. Customers already pay around $5 or $6 per month extra for the 10 percent blend.
“They’re buying into this program for their own reasons,” Gramm said. “And typically, it’s because they care about the environment.”
Gramm stresses that the program has side benefits – for instance, it allows local farmers to diversify their income sources. But a 2011 report released by the BC Agricultural Research and Development Corporation concluded that “biomethane is currently only feasible for a small number of anaerobic digestion systems on large-scale farms in B.C.”
That’s because the cost of installing the equipment is high, and smaller farms would have a hard time producing enough waste to make the investment worthwhile.
One of FortisBC’s biogas producers, Seabreeze Farms in Delta, was recently granted approval to supply almost half of its waste from off-farm feedstocks like fats and oils.
But there are concerns about bringing in off-farm waste to produce biogas. A 2011 Ministry of Agriculture report suggests that this practice could create “the perception that agricultural land is a dumping ground for municipal wastes.” It also listed fears about possible contamination.
Still, the report predicts that biogas production will increase on BC farms, fuelled in part by “consumer demand for renewable energy.”