Ground Source Heat Pump

Heat Pumps are powered by electricity, but for every unit of electricity used, they can extract the amount of heat usually generated by three to four units, which can then be used to heat water.

The most common form of heat pump system is the Ground Source Heat Pump (GSHP) that collects heat stored just under the surface of the earth.

Ground source heat pumps take advantage of the fact that the upper 3 metres of the Earth's surface stays at a nearly constant 10-16°C throughout the year and use the earth as a heat source.

A ground source heat pump can be used to heat or cool buildings.

Air Source Heat Pump

Air source heat pumps offer a viable alternative where land is not available to install pipes in the ground outside.

The principle for heating is the same as for ground source heat pumps but converts the energy from the air outside. Typically, air source heat pumps are less popular than their ground source counterparts because as air is used as the heat source, the efficiency is lower during winter.

Air source heat pumps work on the principle that however cold ambient air is, it is always possible to extract further heat from it.

Both ground source and air source heat pumps use electricity to drive the necessary compressors and pumps, but not to generate any heat.

Solar PV

Solar photovoltaic (PV) uses energy from the sun to create electricity to run appliances and lighting. PV requires only daylight - not direct sunlight - to generate electricity.

A system consists of semiconductor cells that are linked and encapsulated into modular panels - often a rectangular shape about a metre long. These are then interconnected to provide electrical power, which can be harmonised with grid electricity and fed back into the network.

For grid-connected installations, an inverter is required to turn the electricity generated from direct current (DC) to alternating current (AC) and for off-grid installations, a storage mechanism and control system are generally needed.

Solar Thermal

Solar thermal is a solar water heating system that uses heat from the sun to work alongside your conventional water heater.

A solar thermal hot water system comprises of solar collectors (evacuated tubes or flat plates), a heat transfer system (a fluid in pipes) and a hot water store (e.g. a domestic hot water cylinder).

Solar water heating can provide almost all of your hot water during the summer months and about 40-50% year round. The average domestic system reduces C02 by around 350 - 400kg per year, depending on the fuel replaced. This could save you around £50 a year or considerably more if you currently use electricity to heat your water.