When considering biogas as a replacement for fossil-fuel-derived natural gas, or a source of fuel for power or heat, there are the arguments of suitability and efficiency. Some dispute vegetation cover conversion into biofuel deprives the biosphere of its C02 filtering capability, and some others think using biomass from land areas with potential for food crops is morally wrong, especially with the existing of extreme poverty regions of the world.
The more technical reasoning dwells on the subject of efficiency; thus burning biofuels is not much better than fossils, since it puts out greenhouse gases (GHG) into the atmosphere just the same.
Ecotricity, a UK renewable power company, pledges to do business maximizing the environmental benefits of its activities. In addition to supplying 100% green electricity, and green gas, it has installed EV fast-chargers at every motorway service area in Britain, on its Electric Highway network. The Electric Highway was started in 2011, and the company has been instrumental in the expansion of EV use in the UK since then.
The Benefits of Biogas
However, some of these claims seem far-fetched, as if the continued use of fossil fuels was being promoted by biased interest groups. For instance, biofuels have a much shorter half-life than fossils which have taken million years to accumulate, therefore canceling out the filtering / releasing of C02 GHG effect on the biofuels´side. Also, burning harvested vegetation cover from land not considered prime for food crops does not necessarily mean that dense forests will stop capturing C02, as just a couple of examples.
The benefits of a biogas production operation can be seen from the management of a UK green energy company called Ecotricity, who envisions the supply of 100% biogas-fueled power in an environmentally responsible way. His managing director, Dale Vince, in an interview for EVObsession, related that a study commissioned by the company found that green gas, made from grass, could potentially power 97% of Britain’s homes, employ 75,000 people, and inject £7.5 billion into the rural economy every year. He further claimed that if given enough access to the needed land area he could produce biogas, provide thousands of jobs, thousands of acres of wildlife habitats, and all without using any prime agricultural land. Farmers who provide feedstock for the gas-mills would get back the solid residue, as a natural fertilizer, and soil conditioner, saving them the financial and environmental costs of using artificial fertilizers. Also, turning a field over to a wildflower meadow for a season, in a system of crop rotation, greatly enhances the soil, and breaks the continuity of crop diseases.
The nuts and bolts of Ecotricity´s biogas
First source the fuel by harvesting naturally occurring grasses from land previously used for grazing livestock, and lower quality arable farmland, creating new wild-flower meadows in the process, so increasing biodiversity, and providing environmental benefits at the same time. Grass can be grown in rotation, every few years, as a break-crop on lower quality arable land that farmers currently use to grow feed crops for livestock. This will actually improve the quality of the soil, and bring it back into food production, through the addition of the natural fertilizer from the waste product of the gas mill.
Then prepare the biogas for feeding it into a gas mill by the use of a process called Anaerobic Digestion (AD). The grass provides a consistent source of organic material enabling the production of a high-quality Green Gas, through the AD. Organic material, (called feedstock), is broken down by bacteria in an oxygen-free container, producing two main end-products: biogas and a rich organic fertilizer.
Some AD plants in Britain burn the biogas to produce electricity in small on-site generators. Ecotricity Green Gas Mills go one step further. The biogas is ‘scrubbed,’ (mostly, that means having some CO2 removed), and upgraded to the UK’s high environmental, and safety standards, to produce bio-methane, which can be fed directly into the national gas network, to replace fossil-fuel methane that’s used for heating, and cooking in UK homes. That’s the beauty of the Green Gas Mill: you can be cooking on Green Gas, and you won’t even notice any difference.
The Ecotricity Biogas Outlook for the UK
Bio-methane production is thought to have started in 2013, however, by the end of 2015, it had 50 mills producing an estimated 2.5TWh of renewable heat energy, enough to supply heat to 190,000 homes.
A typical Green Gas Mill at 5MW will require about 3,000 acres of grassland to supply 3,500 homes with all the gas they need. That’s less than one acre per household. The construction of 1,000 Green Gas Mills, each of 5MW capacity, would be enough to make up the current shortfall against our 12% target and would create around 15,000 jobs and pump £1.5 billion into the rural economy.
In order to greatly reduce the carbon footprint from the UK, it is utterly important to remove the carbon from heating, which accounts for around 45% of UK`s total energy use. Along these lines, as domestic gas demand is expected to fall in it can be estimated how much biogas would be needed to supply 12% of the UK market as a goal. A typical Green Gas Mill at 5MW will require about 3,000 acres of grassland to supply 3,500 homes with all the gas they need. That’s less than one acre per household. The construction of 1,000 Green Gas Mills, each of 5MW capacity, would be enough to make up the current shortfall against our 12% target and would create around 15,000 jobs and pump £1.5 billion into the rural economy.
By the same token, to supply biogas to 5.000 homes would require the construction of 5,000 Green Gas Mills, each of 5MW capacity, which would be enough to supply 97% of British households, create around 75,000 jobs, and pump £7.5 billion into the rural economy. This would involve a massive scaling up of Green Gas, but it shows how big the potential is. Green Gas Mills can decarbonize UK heating, and help tackle climate change.
Dale Vince was quoted as saying, “We are at the beginning of a revolution in gas, not from fracking but from farms; there’s a whole new industry waiting to be created here, meaning more jobs, and plenty of economic benefits.
We can’t continue using gas from fossil fuels, we are running out, and causing climate change; the great thing about green gas, like green electricity, is we can still live the way we’re used to, but we can do so in a sustainable way.
Making green gas from grass doesn’t compete with food production, it actually supports it, and the farmers working the land. It also helps wildlife, creating new habitats and there’s enough non-food producing farmland in Britain, in principle, to meet 95% of the gas we need, this way.
The strength of public opposition to fracking is crystal clear, and it’s only increasing as well as the significant environmental and health impacts, it’s just an unnecessary risk which we can avoid entirely by pursuing Green Gas.”