RENEWABLE ENERGY - Solar, Ground/Air Heat Pumps & Rainwater Harvesting
SOLAR ENERGY
Solar energy technologies use the sun's energy and light to provide heat, light, hot water, electricity, and
even cooling, for homes, businesses, and industry.
There are a variety of technologies that have been developed to take advantage of solar energy.
Over 70% of the average household’s energy use goes into space and water heating, so a source of free hot water to use instead of commercial energy can make a dramatic financial saving.
Solar Water Heating is the renewable technology of choice for most UK households as it offers a quicker payback (7-15 years for an average household).
Solar Water Heating uses the radiation from the sun to heat water in a panel often sited on the roof which in turn can supply that heat as hot water or to a central heating system.
GROUND AND AIR SOURCE HEAT PUMPS
Heat pumps draw heat from the ground via a ground collector (slinky) or a ground probe (bore hole).
Heat pumps work in much the same way as a fridge but in reverse. In a fridge the heat is transported from inside to outside, while a heat pump takes heat stored below the underground frost line and transports it via the heating system to the house interior.
Some systems are designed to work in reverse as well, cooling the interior in hot weather.
Air source heat pumps use the same principle but extract the heat from the air, rather than the ground. As such their installation is much simpler and cheaper but the available heat is not constant.
These systems require power to drive them, but in an efficient system one kilowatt of energy can generate three kilowatts of heat.
Although the installation of a ground source heat pump to an existing building can be disruptive it has the following advantages:
* Low Operating Cost: provide domestic water heating essentially free or at substantial savings.
* Low Maintenance Costs: fewer mechanical components, making them more reliable, easier to service and less prone to failure. The ground heat exchanger and its associated piping have an expected life of over 50 years.
* Durability: last much longer than conventional HVAC systems because they are protected from harsh outdoor weather.
* Low Noise: systems are among the quietest ever designed.
* Reduced Emissions: do not require external venting, as fossil fuel systems do, so they do not pollute the air.
RAINWATER HARVESTING

Rainwater harvesting is simply collecting rain which falls onto roofs, then storing it and using it as a free resource.
The advantages of rainwater harvesting are that it,