Solar Thermal

Solar radiation is absorbed by a solar collector mounted on the roof of your property, and converted into heat. This heat is transferred to one of the coils of a twin-coil hot water cylinder using a sealed circuit containing a special glycol/water solution. A solar thermal system can provide up to 70% of a domestic properties hot water requirements.

The pump in the system circulates the heated fluid from the solar panel to the cylinder, where the heat is transferred to the stored water.

Solar thermal technology is one of the most reliable, efficient, clean and accessible forms of renewable energy available today. Installing solar panels can help reduce heating bills by providing up to 70% of a household's domestic hot water requirements per annum. As solar water heating depends on radiation, not direct sunlight, it even works on dull days.

FIT’s will be available for MCS approved Solar Thermal Installations from April 2011.

Solar PV - Solar Panels

Solar Photo Voltaic (PV) panels are attached to the roof of your property, converting solar energy into electricity. Solar PV only requires daylight and not direct sunlight to generate electricity, but the brighter the sunlight the more electricity the system will generate.

How do the panels work?

Each panel is made from layers of semiconducting material, usually silicon. When light shines on the solar panel it creates an electric field across the layers. The stronger the light source, the more electricity is produced.

This process whereby light (photo) is converted into electricity (voltage) is called the photovoltaic (PV) effect.

An array of solar panels converts solar energy into DC (direct current) electricity.

The DC electricity then enters an inverter.

The inverter turns DC electricity into 240-volt AC (alternating current) electricity needed by home appliances.

The AC power enters the consumer unit in the house and the electricity is then distributed to appliances and lights in the property.

Excess electricity (if your system is generating more than you are using at that moment) will be exported back to the grid. This electricity will be paid at 3p / Kwh by your electricity company.

What is the Feed in Tariff?

A Feed-in Tariff (FIT) is designed to encourage Micro Energy Generation using renewable energy sources by paying the end-user a fixed rate for every unit of power they produce.

Biomass

The use of wood fuel to space heat property, and to provide hot water indirectly uses ‘energy from the sun’. Photosynthesis makes trees grow, the resulting woody material can be harvested to become fuel.

Modern wood fuel stoves and boilers can reduce fossil fuel consumption and lower carbon emissions.

When wood is burnt it will only give off the same quantity of carbon that it absorbed during its growing cycle. The harvesting and delivery of wood fuel uses carbon but overall wood fuel has a very low carbon foot print compared to fossil fuels.

Carbon Offsetting

10 Tons of C0² are produced on average per person, per year, meaning that; Over the course of an average lifetime (75 yrs) a person will produce 750 Tons of C0².

1 Tree absorbs around 290 Kg of C0² over an 80 year period, therefore, 1 person is required to plant around 35 trees per year or 2800 trees over a lifetime in order to neutralise their individual Carbon footprint.

Typical amenity woodland planting density 1100/ha (3m x 3m).

2800 trees require 2.5 ha (6.25 acres).

Heat Pumps

Solar radiation is continually absorbed by the earth. The relatively constant temperature of the soil can be utilised to provide heating for domestic and commercial property.

Pipe work known as the ‘ground loop’ is buried in the ground and a pump contstantly circulates a mixture of water and antifreeze around the loop. Heat from the ground is absorbed into this liquid which is passed through a heat exchanger in the heat pump.

Low grade heat is now extracted by the refrigeration system and after passing through the heat pump compressor is concentrated into a higher temperature which can now be used to heat water for heating systems and / or hot water use.

The now cooler ground loop liquid passes back into the ground where it absorbs further energy from the ground in a continual process.

The length of the ground loop needs careful calculation according to the amount of heat required and to avoid extracting more energy from the ground than can be replenished by solar radiation.

The loop is normally installed flat or in coils around 1-2 metres deep.

Heat pumps require electricty to run but a typical system will deliver approximately 3 units of heat for every unit of electricity used to power the pump.

Air Source Heat Pumps

An air source heat pump works in much the same way as your fridge except heat is extracted from the outside air. Even when the air temperature outside is below freezing the heat pump will still extract usable heat.

Heat pumps need electricity to operate but the heat extracted from the air is constantly being renewed so as long as you have an electricity supply then you have heat.

The usable heat is at a lower temperature and delivered over longer periods than a conventional gas or oil fired boiler, consequently the radiators will feel cooler to the touch than with a conventional heating system. During the coldest months of the year the heat pump will need to run constantly to heat your home efficiently.

Benefits of Air Source Heat Pumps:

Generally cheaper to install than Ground Source Heat Pumps.
Very little on going maintenance.
Can provide space heating and hot water.
No fuel deliveries and fuel storage required.