The earth acts as a collector of solar heat and the temperature at a fairly shallow depth remains constant at around 10-12 degrees Celsius. We can exploit this heat using Ground Source Heat Pumps.

This is a particularly cost effective method of using solar energy - for every kilowatt of energy extracted, between 2.5KW and 4KW of energy is gained. Ground Source Heat Pumps can provide the heat and hot water required in a home.

There are three important elements to GSHP:

1) The ground loop

This comprises lengths of pipe buried in the ground, either in a borehole or a horizontal trench. The pipe is usually a closed circuit and is filled with a mixture of water and antifreeze, which is pumped around the pipe absorbing heat from the ground.

2) A heat pump
 
This has three main parts:

• the evaporator (e.g. the curved pipe at the back of a fridge) - takes the heat from the mixture of antifreeze and water in the ground loop;
  
• the compressor (this is what makes the noise in a fridge) - moves the refrigerant around the heat pump and compresses the gaseous refrigerant to the temperature needed for the heat distribution circuit;
  
• the condenser (the hot part at the back of a fridge) - gives heat to a hot water tank which feeds the distribution system.

3) Heat distribution system

Consisting of under-floor heating or radiators for space, heating and, in some cases, water storage for hot water supply.

Sanctuary Housing Group projects:

The South West subsidiary is to undertake a feasibility study to determine whether installing a number of Ground Source Heating Pumps would be a viable option to improve the efficiency of some of its stock. Some of the Energy Efficiency Funding money would be used to help with the project.

Construction company Midas will be meeting with staff from Sanctuary Housing Association and this page will be updated with the outcome of these discussions.

Renewable Energy links: