Turning wood into gas powers family farm
A farming family's plan to boost its renewable energy supply led them to combined heat and power gasification, via Germany. Lawson Doe reports.
The on-floor grain dryer, drying woodchip.
Managers of Scotston Farm in Angus were investigating further improvements to their renewable portfolio when they happened across an emerging technology - gasification.
This is typically used in large multi-megawatt power plants. However, wood gas has been used for many years in small-scale installations as a substitute for petrol. The great advantage of the technology is that instead of burning woodchips in a biomass burner, the gasifier converts the woodchip into "syngas" which is then used to drive a modified petrol generator, producing both heat and electricity.
The gasifier of choice for the owner, CKD Galbraith client JS Baird & Sons, is a Spanner Holz Kraft, as Spanner is regarded as among the most experienced manufacturers of mass-produced, small-scale wood gas units.
The Bairds opted for a 45kW unit, sufficient to provide all the electricity needed on the farm, including a 25,000-broiler shed, a 200-tonne on-floor grain drying unit and two heat-pump-equipped houses.
The Bairds toured Germany visiting five different Spanner installations, and a contract was signed for delivery four weeks later. Members of the farm and a specialist installer were given training in Germany.
Back at Scotston, the gasifier, engine and feed-in hopper were installed by the farm members and the specialist installer who had accompanied them to Germany. Once the installation checklist had been submitted, the Spanner commissioning team travelled to Scotston to complete the final checks.
In making the scheme Ofgem accredited, there are three applications:
- Renewable Obligation Certificate (ROC)
- Renewable Heat Incentive (RHI)
- RHI for solid biomass produced by the gasifier reformer process
The Bairds are confident that once all the applications are complete, the tariffs for each, combined with the energy saving and grid export will produce a payback of between two to three years.
The Bairds took the simple option to buy in timber and hire a chipper to create the fuel. The wood chip has to be of a good quality and the correct moisture content.
Diarmid Baird is keen to impart the knowledge he has gleaned in the installation and running of the gasifier. CKD Galbraith may assist with planning and Ofgem applications.
Anyone seeking an initial chat with him should please call me in the first instance.