Renewable Energy or RE is energy that comes from resources which are naturally replenished e.g. bioenergy; geothermal energy; hydropower, ocean energy; solar energy;and, wind energy. It replaces conventional fuels in electricity generation, hot water/space heating, motor fuels, and off-grid energy services.
What is bioenergy?
Bioenergy is a form of renewable energy derived from biomass to generate electricity and heat or to produce liquid fuels for transport. Biomass is any organic matter of recently living plant or animal origin. It is available in many forms such as agricultural products, forestry products, and municipal and other waste.
What is geothermal energy?
Geothermal energy is the energy stored as heat in the earth. There is a steady flow of heat from the centre of the Earth (where temperatures are above 5000°C) through the surface of the Earth (-30 to +40°C) into space (-273°C)—heat flows from hot to cold. The heat is generated by the natural decay over millions of years of radiogenic elements including uranium, thorium and potassium.
Energy is brought to the surface by extracting hot water that is circulating amongst the sub surface rocks, or by pumping cold water into the hot rocks and returning the heated water to the surface, to drive steam turbines to produce electricity.
What is hydropower?
Hydropower is a renewable source of energy which uses the force or energy of moving water to generate power.This power, or ‘hydroelectricity’, is generated when falling water is channelled through water turbines. The pressure of the flowing water on turbine blades rotates a shaft and drives an electrical generator, converting the motion into electrical energy.
Hydropower is the most advanced and mature renewable energy technology, and provides some level of electricity generation in more than 160 countries worldwide. Hydropower plants range from very small to very large individual plants and vast integrated schemes involving multiple large hydropower plants.
What is ocean energy?
Ocean energy is a term used to describe all forms of renewable energy derived from the sea. There are two broad types of ocean energy: mechanical energy from the tides and waves, and thermal energy from the sun’s heat.
Ocean energy is classified as:
WAVE ENERGY: generated by converting the energy of ocean waves (swells) into other forms of energy. There are many different technologies that are being developed and trialled to convert the energy in waves into electricity.
TIDAL ENERGY: generated from tidal movements. Tides contain both potential energy, related to the vertical fluctuations in sea level, and kinetic energy, related to the horizontal motion of the water. It can be harnessed using technologies using energy from the rise and fall of the tides or by technologies using energy from tidal or marine currents)
OCEAN THERMAL ENERGY: generated by converting the temperature difference between surface water and water at depth into useful energy.
What is solar energy?
Solar energy is energy which is created from sunlight, or heat from the sun.
Solar power is captured when energy from the sun is converted into electricity or used to heat air, water, or other fluids. There are currently two main types of solar energy technologies:
SOLAR THERMAL: these systems convert sunlight into thermal energy (heat). In Barbados, solar thermal systems use solar energy to heat water. This heat energy can also be used to drive a refrigeration cycle to provide for solar based cooling. In addition, the heat can also be used to make steam, which can then be used to generate electricity using steam turbines. It is considered more efficient to build solar thermal electricity generators at large scale, typically in the tens to hundreds of megawatts.
SOLAR PHOTOVOLTAIC (PV): the conversion of sunlight directly into electricity using photovoltaic cells. PV systems can be installed on rooftops, integrated into building designs and vehicles, or scaled up to megawatt scale power plants.
What is wind energy?
Wind energy is generated by converting wind currents into other forms of energy using wind turbines. Winds are generated by complex mechanisms involving the rotation of the Earth, the heat capacity of the sun, the cooling effect of the oceans and polar ice caps, temperature gradients between land and sea, and the physical effects of mountains and other obstacles.
Wind turbines convert the force of the wind into a torque (rotational force), which is then used to propel an electric generator to create electricity. Wind energy power stations (known as wind farms) commonly aggregate the output of multiple wind turbines through a central connection point to the electricity grid. Across the world there are both on-shore (on land) and off-shore (out to sea) wind energy projects.