Renewable Energy

WIND GENERATION

Wind turbines convert the kinetic energy of the wind into electrical energy. Given that the UK has roughly 40% of the entire wind resource of Europe, there is significant potential to extract energy from this source. However, to date this has been under utilised. Domestic wind turbines are much smaller than those seen in wind farms, but they operate in much the same way, providing output from just a few tens of Watts to several kilowatts for household sized installations. Of all the domestic renewable energy systems, wind turbines are probably the most controversial, whilst also being more difficult to predict in terms of performance due to the large number of variables involved.

SOLAR HOT WATER

Solar Hot Water Systems collect the sun’s energy and transfer it into your hot water tank, supplying most of your needs, even in winter.

Annually the UK receives solar radiation equivalent to the typical output of 1,000 power stations, and provides most of our renewable energies by driving wind, wave and water systems, and sustaining plant-life. Solar energy may be used more directly to provide domestic hot water. The average annual domestic hot water demand requires around 3,000 - 4,000 KWh per household; with a total annual household energy demand of 26,000kWh on average.

GROUND SOURCE HEAT PUMPS

Heat pumps work on a very similar principle to the common refrigerator in that they pump heat from one location and into another. At about one metre beneath our feet, the earth maintains a constant temperature of around 10-12 Celsius. This is because heat from the summer sun is stored in the ground and gently released back to the environment during colder periods.
Heat pumps tap into this energy, transferring the solar energy stored in the ground to provide heating and hot water for the home, in much the same way as your refrigerator transfers heat from inside the fridge and into the room. At the end of the heating season, the sun allows the temperature of the ground to recover again.

PHOTO VOLTAIC

The word "photovoltaic" combines two terms - "photo" means light and "voltaic" means voltage. A photovoltaic system uses photovoltaic cells to directly convert sunlight into electricity.

COMBINED HEAT AND POWER

Combined Heat and Power (CHP)* is an efficient way to generate electricity and heat simultaneously. Fuels (such as gas, coal, oil, biomass and hydrogen etc) are burnt to release energy which is then harnessed to serve some useful purpose. The most basic form of the released energy is heat (as in a domestic boiler) and this can then be distributed via a heat-exchanger and a circulating fluid to be used for water and space heating. Quite a large proportion of the heat may be wasted through the flue but by careful engineering that too can be used. For example a second heat exchanger could extract more of the heat by partly condensing the hot exhaust gases and that is the principle of a condensing boiler. No electricity is produced by this method and it is therefore not a CHP system but it has the advantage of being highly efficient at 90% or more.

There are several methods by which Combined Heat and Power can be generated and the dual forms of output power explain to a considerable degree why they too can be highly efficient. However, these techniques are inherently more complex and some of the options are more practical than others.

BIOMASS HEATING

In energy terms, biomass heating refers to the use of a wide variety of organic material for the generation of heat.

Biomass is any form of biologically produced matter, which can be burnt as a fuel. Common sources of biomass fuel include forestry waste, sawmill residues, and dedicated energy crops, such a miscanthus grass and willow coppice.