The UK’s National Grid (s NGG) says up to half of the country’s homes could be heated using biogas made from waste, using technology that until now has been primarily focused on electricity generation.
Most biogas production in the cleantech industry today is used to generate electricity via gas-powered turbines, but it’s not very efficient. In a new report, the National Grid says that currently about 1.4 billion cubic meters of biogas are produced in the UK and used to create electricity — at about 30 percent efficiency. If the biogas is injected into the existing gas pipelines, it could be used for heating at efficiency rates of more than 90 percent.
The biogas first needs to be cleaned or upgraded to meet gas pipeline specifications, but the technology is already being used in other parts of Europe.
“In the Netherlands and Germany they’ve both got quite aggressive targets for 2020 or 2030 to get a reasonable portion of their gas demand from biogas,” said Janine Freeman, head of the National Grid’s Sustainable Gas Group, told us. German power company E.ON set up its own biogas-to-pipeline firm a couple of years ago — E.ON Bioerdgas — and has at least one plant up and running.
The E.ON plant in Schwandorf, Germany, uses food crops such as maize as a feedstock, but it’s a good example of what could be done with the technology, instead of just burning the biogas to make electricity. The plant can produce about 16 million cubic meters of biogas per year, enough to supply 5,000 homes. Last November, E.ON announced plans for a second plant in Aiterhofen.
The National Grid already has some experience in the technology, but not in the UK. At its operations in the Northeast U.S., it takes landfill gas from the Staten Island landfill and injects the cleaned gas into New York pipelines.
In the UK, all of the country’s waste — including sewage, manure, agricultural waste, food waste, wood waste and more — would need to be diverted to biogas production in order to cover half of the residential gas needs. “That is a technical potential, really, just based on all of that waste going to the appropriate biogas production process, but even if a small portion of that could be achieved, then actually that’s still something to work for,” said Freeman.
In a business as usual scenario, where there’s no change to the way waste is handled, the company believes enough biogas could be produced to cover 15 percent of residential gas demand in the country. A more likely scenario would be something in between, with a boost in recycling and composting, as well as some waste going toward biogas.
At the high end, the plan could cost around £10 billion ($14.4 billion), over and above the cost of a new waste infrastructure, which would likely include more biogas production plants, even without a biogas-to-pipeline plan. The National Grid said a new waste infrastructure needs to be built anyway, to reduce the amount of garbage going into landills.