Alternative energy sources
There are two types of alternative energy sources, Active and Indirect.
Active Systems
The term 'active' means when hardware collects, converts and delivers energy. And can be through wind, geothermal and bio energy. Solar panels on roofs and south facing surfaces can be used to heat water or air, and can also generate electricity.
Wind Systems
The UK holds 40% of the European wind resource.
This power can be generated by single turbines, small clusters or wind farms.
Good combination with PV's, for example in winter it is windy and summer sunny.
Sometimes the integration with buildings is difficult as the turbines need lamina flow.
A 5m diameter turbine can produce 125 Watts at peak.
However turbines can greatly affect the soil its built on. Within a 50meter radius of a turbine, after a certain amount of years the soil becomes infertile. This is because all the worms and insects in the ground that keep it healthy leave due to the vibrations made from the turbine.
Bioenergy Systems
Biomass is an all plant and animal matter from the earths surface, and harvesting these to create heat and electrical energy.
There are two different processes for Bioenergy.
Through combustion or through Anaerobic digestion.
Geothermal Systems
This form of energy is created from the Earths interior, by using a heat pump heat can also be drawn from a water source such as a river, ground or waste water.
As the fluid passes through the pipes it gradually absorbs heat energy from the surrounding environment. The fluid then returns to the heat pump slightly warmer than it left. The heat pump upgrades this heat to a higher level to provide heating.
Unlike other systems heat pumps can also be used for cooling purposes by reversing the process.
Solar Systems
One type of system is the Flat Plate collector. Heat from the sun is transferred to the air or liquid that passes throughout the collectors.
Absorber plates need to have very good conductive properties though. Being made from aluminium or copper is the best choice.
Liquid collectors collect solar energy and it heats up the fluid that is flowing through the tubes/pipes inside or adjacent to the absorber plates. To make sure the energy is conducted properly from the plates to the fluid, the tubes are always in constant contact with the main absorber plate.
Air collectors are mainly used for space heating, and due to natural convections, the heated air ascends along and past the absorber plates. And also since air is not as good as conducting heat as liquid, less heat will be transferred from the plate to the air.
Photovoltaics
PV means utilising the suns energy to which produce electricity from. When photons from the sun hit the PV panel, electrons in the PV cells are heated and begin to move around, then creating electricity. They actually perform better in lower temperatures as they do not need heat to produce electricity only light. However with cloud the energy output can be reduced.