Biomass boilers bring energy savings and added income for strawberry growers, Somerset
By investing in two biomass boilers, one Somerset strawberry grower is on track to benefit from £160,000 per year in fuel savings and added income while enabling the business to make the most of an earlier premium strawberry market.
With 14 acres of strawberries grown undercover at Bower Farm, Bridgwater, heating costs are among the highest for the Team Green Growers family business. As a result, last year the team decided to look at renewable energy options to drive down energy costs.
The Winter family of brothers Adrian, Richard and Phillip and father Albert, produce Elsanta strawberries for Sainsbury's supermarkets and correct environmental temperature is crucial to maximise plant performance and help ripening. Correct and consistent heating is essential in maintaining night time temperatures at between 8 - 14 degrees Centigrade during key parts of the growing season
After seeking the advice of moleenergy - the renewable energy arm of Mole Valley Farmers - installing two biomass boilers was seen to be the most sensible and profitable route. Putting in a Viessmann Pyrot 540 kW and Pyrot 300 kW woodchip boiler would meet their energy demands and allow the business to gain additional income from the government's Renewable Heat Incentive (RHI).
To make the move over to renewable energy, the family invested in the two biomass boilers, buffer storage tanks, a woodchip store and heat exchange unit to link up the old system to the new biomass boilers. Adrian says the move was simple.
"We originally had two oil boilers. To move over to the biomass boilers we took out one of the oil boilers and plugged in the new system. It was a simple retrofit to the existing pipes,” he says. One oil boiler has been kept as a backup for the heating system and also to offer support to the biomass boilers when greenhouse temperatures drop heavily.
With a total annual requirement of 900 tonnes of woodchip to feed the boilers, creating a woodchip store was a key consideration. To house the boiler room and woodchip, a 3600 sq. feet shed has been purposely erected next to the greenhouse. Adrian says moleenergy's advice was crucial in ensuring the correct siting of the facility.
At a total installation cost of £350,000, Adrian Winter believes the biomass boiler system will deliver around £80,000 per year savings in fuel over the farm's conventional oil burning system. In addition, the Winters will receive £80,000 per year for 20 years from the RHI, which on its own will enable the project to be paid back in five years.
Having sought the advice of moleenergy, the Winter's also decided to put in two boilers rather than the one they originally planned. This meant they would be able to meet seasonal demand more effectively.
- Pyrot 540 kW Biomass Boiler
- Pyrot 300 kW Biomass Boiler
Statement from installation partner
Andy Taplin from moleenergy explains: “The two boilers can work independently or together, for more efficient energy production. Modulated output also means the 300 kW boiler for example can work at only 100 kW, if needed, to meet demand.”
As soon as there is demand for heat in the greenhouse, the boilers kick into gear. However because they take half an hour to warm up, in the mean time a series of buffer tanks totalling 30,000 litres pump hot water immediately around the pipe network in the greenhouse. When the boilers have heated up, they then take over from the tanks.
Adrian says that the fact there is no time lag before heat is delivered, means there is a more consistent temperature in the greenhouse which ultimately benefits strawberry production.