‘Renewable’ energy is a term used for the sources of energy that are natural and continuous in the environment. All forms of renewable energy can be traced back to the sun, or the interaction of the sun and the moon. These sources of energy are essentially inexhaustible.
Why do we need it?
We need renewable energy for a couple of reasons.
It is a free resource. Once the equipment is in place, be it a solar panel or a wind turbine the only on going cost is the maintenance. Unlike conventional forms such as oil, that requires exploration, surveying, extraction, transport, and refining.
They are clean to capture. Energy is used in every aspect of our day-to-day lives and we are now inseparable from it. Current methods of producing energy products release large quantities of greenhouse gases that fuel climate change.
They will not run out, so from the point of view of energy security, we will not have to rely on shipping energy or raw materials for energy production from abroad.
What can renewable energy be used for?
Renewable energy can be used primarily for electricity production that can be feed into the National Grid and used as normal.
You would not notice a difference in your home, once captured and turned into electricity it is identical to electricity from any other source.
Some sources of renewable energy can also be used for heat production. Geothermal and solar water systems can be used to heat buildings or provide hot water.
Renewable energy can also be used for transport. Bio-diesel or vegetable oil can run a diesel engine with minor modifications and the expanding use of electric cars means electricity from other renewable sources can be used for transport.
Types of renewable energy
Biomass -
Biomass is organic non-fossil material, that is all plant and animal material. A number of different forms of biomass can be burned or digested by animals to produce energy. Biomass is a very resourceful material and can be used to produce heat, electricity and a combination of heat and power (electricity).
In a domestic setting common biomass systems include woodchip burners for household heating and hot water or bio-diesel for use in vehicles. Biomass technology is carbon neutral as the carbon dioxide released from burning the fuel was originally captured from the atmosphere during the plants/animal growth.
This increasingly popular technology can be used for heating, cooling and hot water in both domestic and commercial settings. By using a system of underground pipes heat can be exchanged between the building and the ground. This can replace the need for heating in the winter and air conditioning in the summer.
Savings of up to 70% on your fuel bills are possible with your existing central heating system. The systems can be adapted to a range of applications and needs.
These domestic turbines have received a great deal of media attention recently. It should be stressed that to generate electricity in good quantity a wind survey and consultation should be sought before installing a turbine.
Whilst the UK has an average wind-speed of 6m/s and some 40% of Europe’s wind energy resource, the actual conditions vary on a local scale and turbulence caused by nearby obstructions may dramatically affect performance.
Commercial wind farms are being used in the UK and are being sited both on and offshore. There are more projects being approved all the time, recently the 270 turbine London Array was approved and is expected to generate enough electricity for more than 550 000 homes.
Hydroelectric power systems use water held at a height to turn a turbine and generate electricity.
They require access to a suitable source and cost a great deal to set up. They can however be very reliable and can provide your electricity all year round. Any surplus electricity can then be sold back to the grid.
Environmental concerns must also be addressed when choosing a site for a hydropower installation, to ensure that the ecology of the watercourse is not adversely affected.
Commercial systems can produce many megawatts of electricity and are part of the governments plan for increased renewable sources of energy. There are currently over 200 large capacity hydroelectric stations in the UK.
Solar hot water systems are much cheaper than PV panels and can provide almost all of your hot water during the summer months and about 50% all year round.
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