Open Loop Ground Source Heat Pumps
For millions of years, the sun has provided all the energy needed to support life on earth, every day providing five thousand times the amount of energy we consume worldwide.
The earth continually absorbs and stores heat from the sun, maintaining a year round temperature of approximately 8oC to 12oC at depths below 1 metre. Heat can be taken from water flowing through the ground and used to provide domestic heating and hot water all year round via a heat pump. This is known as 'open-loop' ground source heating; it is extermely efficient and can also provide cooling at a fraction of the cost of conventional air conditioning.
The water can also be filtered for domestic consumption before being returned to the ground via a harvesting tank, from where it can be pumped for garden watering or other 'grey-water' uses.
Unlike rainwater harvesting, as long as the heat pump is in operation the harvesting tank is being replenished. An abstraction licence is not required from the Environment Agency provided the abstraction rate does not exceed 20,000 litres per day.