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Energy Summary

Energy House 2
  • Greenskies solar panels
  • Ground source heat pump
  • Air source heat pump
  • Greenstar Heatslave oil boiler
Energy House 2
The Energy Centre, Crowle, Worcester

This data is taken directly from the S family's house on a weekly basis.

The Greenskies solar panels are used to heat the hot water and the Greenstore ground source heat pump is used to top up the hot water, when necessary. The Greenstore ground source heat pump is also used to heat the swimming pool or the central heating system, depending on the time of year.

Please note that payback periods for ground source heat pumps are significantly dependent on usage and energy suppliers.

What do the figures mean?

The letters kWh are an abbreviation of kilowatt hour and this is a measurement of energy. Your energy supplier's bills will show the amount of energy used in kWh and also how much they charge for each kWh. You can use this information on your energy bills to work out the benefits of renewable technologies, A-rated appliances, and the effect that SAP ratings have on the energy usage of your property.

The Air to Air Heatpump uses the same principle of operation as the Ground Source Heat Pump (GSHP) except that in this unit the heat is taken from the external air rather than the ground. The heat gained from the external air is used to warm the internal air using the same compressor technology as the GSHP. As for the GSHP this compressor technology gives efficiencies in the range of 300% to 500% which means that for every unit of electrical energy used, 3 to 5 units of heat energy are produced. As a comparison a standard electric heater only produces 1 unit of heat energy for every unit of electrical energy used.

The figures shown represent data taken in a typical week at the Energy House.

Energy summary for Energy House 2

Output from solar

Energy from Solar panels to hot water tank (1)2.4 kWh

Output from ground source heat pumps

Energy from heat pump to the hot water tank (2)7.8 kWh
Total energy from heat pump to hot water tank and swimming pool (3)0 kWh
Electrical energy used by heat pump from ground (4)2.5 kWh
COP ratio of useful heat energy produced by HP (5)3.1

Output from air to air heat pumps

Energy from Air to Air Heat Pump (6)0 kWh

What do these figures mean in savings?

Free baths per day from Solar = 0.7
Free baths per day from HP = 1.8

Based upon a 90 litre bath with 43 degree temperature and with incoming cold at 10 degrees.

Last updated: 20 October 2008

(1) Energy provided by the solar panels to the hot water tank which would otherwise have been supplied by the heat pump (2) Energy from the heat pump to the hot water tank. This is energy that the heat pump has extracted from the ground and is used to supplement energy from the solar panels (3) Total energy provided by the heat pump to the hot water tank and the swimming pool (4) Total electrical energy used by the heat pump to extract energy from the ground (5) The COP is a measure of the efficiency and performance of the heat pump. This is the ratio of the useful heat energy produced by the heat pump compared to the electrical energy used to run the heat pump (6)

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