Pellet boiler warms new butterfly glade at Colchester Zoo

As the fourth in a series of installations, Bentley Fire Shop has supplied and installed a 42kW EkoHeat biomass boiler at Colchester Zoo, Essex. The new pellet fuelled unit, which has replaced an ageing and inefficient oil boiler, has been sited at a new walk through butterfly enclosure, supplying heat for the butterflies as well as enclosures for the mangabey monkeys and lemurs.

Commenting on the installation, Paul Maguire, Estates Manager at Colchester Zoo, said: “We’ve used Bentley Fire Shop for a number of projects that have utilised biomass boilers. This pellet boiler has been specifically chosen, as not only is it far more eco-friendly than the old system, it is also eligible for the Renewable Heat Incentive (RHI).

The biomass system from Bentley Fire Shop is eligible for the non-domestic renewable heat incentive (RHI), providing up to 8.4p per kilowatt hour (kWhth) produced over the lifetime of the installation (for 20 years). Paul continued: “Now that the plant has been commissioned and is up and running, we’ve estimated that two thirds of RHI payments received will cover the cost of running the boiler, allowing us to invest the remaining third of the payments back into the Zoo.”

The Non-Domestic RHI is a Government environmental programme that provides financial incentives to increase the uptake of renewable heat. For the non-domestic sector it provides a subsidy, payable for 20 years, to eligible, non-domestic renewable heat generators. The EkoHeat boiler at Colchester Zoo will supply 8.4p per kilowatt hour of heat generated.

The RHI eligible EkoHeat boiler incorporates an innovative burner feeding system, which is a hybrid concept that brings together the advantages of the traditional ejector and bottom feeder systems. This prevents changes in combustion caused in the ejector system, while also improving safety systems.

It also has a set of cleaning springs that retain flue gases to improve performance, while at the same time cleaning ash residues in the heat exchanger. The springs are connected to the shaft of a motor via a cam system, which regularly moves them vertically and cleans the heat exchanger.

Gordon Bennett, Managing Director at Bentley Fire Shop, said: “We’re delighted that an EkoHeat biomass boiler has been installed at the Zoo, with the project set to considerably reduce the running costs for the heating and hot water systems. Although this is one of the smaller units specified to date, the payback from the high efficiencies and RHI tariffs have made it a great example of how to utilise biomass in a commercial application.”