Ground source heating is a renewal energy system of storing energy in the ground. A heat pump collects heat and stores it as energy for space and water heating use in the home. It can be installed using bore holes or shallow trenches. Heat collects in pipes containing water. Although some systems can be reversed in summer to provide cooling rather than heat, these systems are not currently eligible for a grant.
The time taken to install a ground source heating system is around 7days, excluding site inspection. Ground source heat pumps work particularly well with heating systems that run at low water temperatures, and are best suited to underfloor heating systems. It is possible to use this system with conventional radiators, although generally larger radiators are required. There is no need for regular maintenance and servicing of ground source systems. Taking the cost saved by minimal servicing requirements and the rising price of gas and electricity, considerable savings on household fuel bills can be made, at around 44%.when compared to gas usage. Savings per year can amount to £410 compared with gas usage, up to £1,000 compared with electricity usage, up to £750 compared with oil usage and up to £350 compared with solid fuel usage. Carbon dioxide emission savings amount to between 1.2 and 6.5 tonnes per year.
Some heat pumps run on a standard UK single phase electricity supply, although most require a three phase supply. A heat pump unit is the approximate size of a domestic fridge. Ground source systems are very energy efficient if used with an Economy 7 system or similar. For every kilowatt of electricity used they generate 3-4 kilowatts of energy. Installation costs are around the same as for a conventional heating system.
There are several drawbacks involved with using a ground source system as a form of heating space and water. As an environmentally friendly source of energy, carbon savings are minimal, unless used with a green electricity supply. In addition, refrigerants are used in a ground source heating system, although new and greener products are reaching the market. Installation costs are relatively high compared with most other heating system installations. Planning permission may be required if a bore hole is needed and require a large area for installation. The alternative to a bore hole is a trench which requires even more space. On a positive note, a typical 8-12kw system will cost around £6,000-12,000 to install, excluding connection to a distribution system. In addition, ground source energy is a reliable and constant source of heat. There are no external components visible outside the house, no external fans and the system is quiet running. The life expectancy of a ground source heating system is around 40 years. Grants are available for installation of a ground source heating system. All in all, considerable savings can be made by installing a ground source heating system.