Energy Innovations were chosen to supply and install the HPKI-K Gilles pellet boiler at St Helens Rugby Stadium. The boiler is being used to provide both heating and domestic hot water requirements around the new rugby league stadium, corporate entertainment areas and offices at St Helens, Merseyside. The stadium has a capacity for 17,980 people and is being built on the old United Glass Works site. They decided to install a biomass system as it meant that they would fulfil their renewables obligation for a new build and it would attract a useful income from the Renewable Heat Incentive payments it is eligible for.
The Gilles pellet boiler was chosen for its proven reliability, high levels of automation and its ease of operation. It is integrated into the buildings BMS system and is the base load boiler for the site working in conjunction with two gas boilers. There will potentially be long periods when the pellet boiler will be capable of meeting the entire load of the site, offering the client fuel savings and useful RHI income. The site has very variable energy requirements, for instance a match day when all the facilities will be in use or a day when the stadium is empty with just a few offices and staff on site. This combined system offers the client the most cost effective deployment of a biomass system. Though it would be possible to cater for peak demands with a biomass boiler, it would not be cost effective as these periods would be so short. Therefore using gas boilers to provide the top up capacity at peak demand makes it a practical and financially viable solution.
Pellet Wood fuel
Pellets offer a range of benefits as a fuel solution. For this installation a pellet boiler was easily incorporated into the fabric of the new building. The pellets are supplied via blown delivery and this is an easy, clean method and proved attractive to the client. Pellets have a relatively high energy density per cubic metre, optimising available fuel storage area on site. Pellets flow from V section floor profiles in to open section augers, negating the need for mechanical agitation again providing cost effective solutions to the client.
The plumbing local to the boiler incorporates a low loss header and no thermal storage vessel. The capacity of the pipework in the stadium and the boilers ability to modulate quickly to the prevailing load negates the need for such a vessel which saves space.
The Fuel Store
The fuel store is of simple concrete block construction with a central open pellet auger surrounded by inclined wooden sides with a storage capacity of 26 tonnes. In periods of heavy use the fuel store will need to be refilled every 6 weeks. There is a fuel delivery pipe and also a vent pipe. The vent pipe ensures that dust generated in the filling process can be captured and is not a nuisance.
With financial backing of the Renewable Heat Incentive (RHI), this installation is receiving in the region of £20,000 per annum. Payments to RHI beneficiaries will be paid over a 20 year period and are paid quarterly and in arrears based on actual energy consumption used. The level of payment is calculated based on installed capacity and the rates are index linked to the retail price index.