Our R&D efforts focus in four main areas: improving AD productivity, reducing build costs, AD/solar hybrids and energy crops which don’t compete with land required for food production.
AD productivity, efficiency and value engineering
We are actively exploring ways to improve the productivity of AD to increase output, and also reduce initial build costs for AD and biomass boiler systems, with the overarching aim of making biogas plants more viable at lower energy tariffs.
If clean energy is to be seen as a genuine alternative to traditional fuels, it has to compete directly on cost. Solar energy is dropping rapidly in price, to the point where it is almost on a par with coal; that milestone will probably be reached in the next few years. Now we have to make AD equally competitive.
As a company, we want to be at the forefront of driving the commercial viability of biogas.
One part of that is improving productivity to increase gas output from the same material, which is the focus of our research partnership with Oxford University led by Mike Mason (see Our sponsors). By examining how AD works in nature (in a cow’s stomach, in fact), we can learn how to make manmade AD plants more efficient.
The other part is value engineering: reducing the capital expenditure needed to get an AD or biomass boiler plant up and running. One important element of this is exploiting the two-stage AD process, which uses smaller tanks and therefore requires far less building material during construction.
Solar power is cheap and plentiful, but intermittent – in simple terms, power is only generated when the sun shines.
We are exploring the potential for hybrid AD/solar technology, where solar energy is generated during the day and gas is stored for release when the sun goes down. This hybrid facility would be one step on from the co-located AD and solar plants we are already developing at Gorge Farm and Kpong Farm.
One of the few drawbacks of biomass as an energy source is the threat of energy crops displacing food crops, leading to shortages. Our policy is that we will not build or operate a plant which uses energy crops which displaces food production. The Gorge Farm AD unit only uses crop residue and vegetable offcuts from VP Group’s export business.
We are engaged in the search for energy crops that can be grown in semi-arid regions and will not displace food crops.
Our work focuses on Crassulacean Acid Metabolism (CAM) photosynthesis, a carbon-fixing pathway that evolved in some plants (mainly cacti) as an adaption to arid conditions.
CAM plants can photosynthesise without losing moisture during the day, as other plants do, allowing them to grow efficiently on 250–500mm of rain per year.
If CAM plants can be grown in sufficient quantity in semi-arid areas, energy from agriculture can be produced where previously land use has been minimal. This can open up a huge opportunity for grid-friendly electricity, create jobs in rural areas and improve land use and fertility.
We are exploring the possibilities of using CAM plants as biomass at a 3.6ha trial site at Gorge Farm.