Aysgarth School in Newton Le Willows, near Bedale, North Yorkshire was founded in 1877 and takes pre-prep boys and girls from 3-8yrs – day only and prep boys from 8-13yrs – boarding and day. In 2012 a decision was made to construct a new Sports Hall and since Aysgarth was keen to operate the school in an environmentally friendly manner, it looked to renewable energy to provide heat and hot water to the new building.
Aysgarth considered various renewable options including solar, biomass and a ground source heat pump (GSHP) system. A playing field adjacent to the site of the new Sports Hall was identified to accommodate the necessary ground collection pipes for the GSHP which would power the underfloor heating and hot water for the new Hall.
After consideration Aysgarth decided that the ground collector loops, which absorb heat energy from the ground, should be installed horizontally in trenches rather than using vertical boreholes. The ground loop array consists of 36 x 100metre flexible MDPE collector pipes, buried underneath the sports field. Construction work on the Clement Hales Sports Hall, named after the founder of Aysgarth School, started in September 2012 and the excavation of the trenches to house the GSHP’s collector pipes started in October/November. To avoid disruption to the running of the school work took place as far as possible during school holidays, but when pupils were at school the construction areas were securely enclosed.
One problem Aysgarth encountered was that the school runs single phase electricity and larger GSHPs normally run on 3 phase. However, Ecovision, the renewable energy specialist chosen to supply and install the GSHP system, overcame this problem by installing six single phase pumps connected in parallel.
Commissioned in April 2013 Aysgarth’s renewable energy system is eligible for the Government’s Renewable Heat Incentive (RHI). The RHI pays participants of the scheme who generate and use renewable energy to heat their buildings and under the RHI scheme the school will receive payments for the next 20 years.
Currently, the tariff is worth in the region of £8,640 per annum with a possible rise which the Government has yet to confirm.The total cost of the renewable energy system, including the excavation of the collector pipes and the groundwork necessary to link the collector pipes to the plant room was just under £145,000 broken down approximately as follows:
6 x GSHPs – £82,700
Groundworks – £38,800
Construction of plant room to house the GSHPs – £23,300
All costs are subject to VAT.However, the savings that a GSHP can deliver when compared to heating and providing hot water to the Sports Hall using oil, as a possible alternative, are significant. It would require approximately 22,000 liters of oil which would cost £13,200 a year based on 60p per litre.
Whereas using the GSHP system to provide the same amount of heat (approximately 176000kWhrs) the school would use approximately 58000kWh of electricity and, based on 12p per kWh, this would result in an annual bill of just £6,960. A saving of almost half of the cost of using oil.From the perspective of carbon reduction, using oil to heat and provide hot water to the Sports Hall would have produced approximately 63000kg of CO2, whereas the GSHP produces just over half of this amount at 34000kg.
“The GSHP has enabled Aysgarth to ‘go green’, expose its pupils to the need to protect the environment and actively demonstrate how this can be achieved.“Our choice of a renewable energy solution is a great way forward for the school. Future generations will not be burdened with massive running costs around the Sports Hall as it will always be cheap to run. The GSHPs means that we are not reliant on third parties to supply any kind of fuel, be it fossil or pellets, which provides a comfort factor around being much more in control of our energy costs than we would otherwise be”, said Andrew Francis, Aysgarth’s Estates and Finance Manager.