Five Gilles 195kW Biomass Boilers provide heat to 8 Broiler Houses. Each single boiler provides heat to a pair of Houses via their own district heat main. As fully separated systems they are eligible for the Sub 200kW Renewable Heat Incentive Tariff, optimising the payback opportunity for the owner. Combined boiler houses and fuel stores ease the complexity of these systems and make day to day operation simpler and sustainable. The Boilers themselves are all heavy duty industrial units capable of handing a range of qualities of fuel. The robust nature of this system continues in the steel heating mains offering highest possible temperatures are the commencement of the crop.
The 195kW moving grate industrial boilers enable high moisture content chip to be burnt without loss of efficiency. The boilers have been initially configured to run on chip produced from cord wood and chipped directly into the store on site. The boiler has a high turndown capability to enable it to maintain combustion with minimal detrimental effect at times of low heat demand. Remote monitoring enables the client and Energy Innovations to monitor performance and, if required, change settings to maximise the efficiency of the system. In the event of any issues with the boiler, alarm emails and text messages are sent out automatically.
The Fuel Store
Each of the 5 boilers is individually fed from 2 common bulk fuel stores. The use of hinged arm sweep collectors over a sprung arm alternative means that lower quality chip can be used, giving the farm manager a choice of cheaper fuels from a wider range of suppliers. The total storage in the barn was specified so that one barn load of chip would cover one crop at the coldest times of the year. Fuel is either delivered by chip liner lorry in bulk loads of 90m³ or cord wood is chipped directly into the store.
Heat delivery is via pre insulated underground steel heating mains, specified to provide long term maximum efficiencies to each shed. The 6 smaller sheds have 2 fan coils per shed whilst the larger sheds have 4. Heat meters are installed on all boilers and at the entry point to each shed enabling detailed records of energy used on each crop. The shed heat meters are fully integrated into the site management system. Load sensing pumps in combination with motorised valves in the sheds ensure that only the hot water that is required is pumped through the heating main, this minimises losses in the heat main and pumping costs.