Renewable Energy
Is derived from sources which are naturally replenished or are practically inexhaustible. They are often described as 'clean', 'green' or 'sustainable' forms of energy because of their minimal environmental impact compared to fossil fuels.
However, there is some controversy about which forms of energy are genuinely renewable, as there are inevitable environmental consequences from any form of energy production and consumption:
Manufacture, transportation and installation of equipment.
Maintenance of equipment.
Decommissioning.Distribution of energy.
Displacement of other activities (such as food production).
The National Planning Policy Framework (NPPF) suggests that renewable and low-carbon energy: 'Includes energy for heating and cooling as well as generating electricity. Renewable energy covers those energy flows that occur naturally and repeatedly in the environment – from the wind, the fall of water, the movement of the oceans, from the sun and also from biomass and deep geothermal heat. Low carbon technologies are those that can help reduce emissions (compared to conventional use of fossil fuels).'
Very broadly the range of energy production techniques that have been described as 'renewable' includes:
Tidal energy: Tidal power can be generated in two ways, tidal stream generators or barrage generation. The power created though tidal generators is more environmentally friendly and causes less impact on established ecosystems.
Wave power: Wave power is the transport of energy by ocean surface waves, and the capture of that energy Wave energy can be difficult to harness due to the unpredictability of the ocean and wave direction.
Wind power: Wind power is the conversion of wind energy by wind turbines into electricity or mechanical energy. Large-scale wind farms are typically connected to the local power transmission network with small turbines used to provide electricity to isolated areas
Hydropower: Water power derived from the energy of falling water or fast running water, which may be harnessed to generate electricity
Solar energy: Photovoltaic (PV) Solar power is harnessing the suns energy to produce electricity. Solar cells are becoming more efficient, transportable and flexible, allowing for easy installation.
Geothermal energy: Geothermal energy is an efficient way to extract a renewable energy from the earth through natural processes. Geothermal power is cost effective, reliable, and environmentally friendly, but has been geographically limited to areas near tectonic plate boundaries.
Bio energy: Biomass refers to living and dead biological material that can be used as fuel or for industrial production. Biomass may also include biodegradable wastes that can be burnt as fuel