Renewable Energy, also known as ‘Clean Energy’ refers to the energy that is generated from natural sources or processes that are constantly replenished on a human timescale.
The most common sources of renewable energy are solar, wind, hydro, geothermal and biomass.
Renewable energy replace conventional fossil fuels in four key areas : electricity generation, water heating/cooling, motor fuels and rural (off-grid ) energy services.
Across the world the use of renewable energy usage is on the rise as it offers abundant, clean and inexhaustible source of energy.
The most common of types of Renewable Energy technologies are:
1. Solar Energy
The energy from the Sun is harnessed into Thermal or Electrical energy using various technologies. The three main ways to harness solar energy are,
Photovoltaics (PV) are also called Solar Cells – Directly convert Solar Energy to Electricity via an electronic process in semiconductors. They can be used to power anything from small electronics such as calculators and road signs up to homes and large commercial businesses.
Concentrated Solar Power (CSP) - Use mirrors to concentrate the sun’s energy to drive traditional steam turbines or engines that create electricity.
Solar Heating & Cooling (SHC) Systems – Collect the thermal energy from sun and use this heat to provide hot water, space heating, cooling and pool heating for residential, commercial and industrial applications.
2. Wind Energy
Wind Energy is among the fastest-growing renewable energy technologies in the world.
The kinetic energy of the air currents is transformed to electricity using wind turbines or wind energy conversion systems. There are two types of wind energy based on where the wind turbines are installed,
Onshore Wind energy
Off shore Wind energy
Onshore wind farms are the most popular form of Wind Energy, but there is growing interest in developed countries to construct offshore wind farms which offer tremendous potential. Wind with battery energy storage for grid optimisation is another application of Wind power to meet the energy demand.
3. Hydro Energy
This form of energy harnesses the power of water in motion – such as water flowing over a waterfall to generate electricity.
There are three basic types of hydropower facilities: Impoundment, Diversion and Pumped Storage.
The sizes of Hydroelectric power plant facilities range from small & micro plants that individuals operate for their own energy needs or sell to power utilities to large power plants that supply many consumers.
4. Geothermal Energy - ‘The Treasure under your feet’
Geothermal Energy is the heat derived from the decay of radioactive elements in the Earth’s crust and the naturally occurring sub terrain hot water reservoirs.
Today this energy is harnessed to generate clean electricity, heat & cool buildings, as well as for other industrial purposes like fruit and vegetable cultivation.
5. Biomass Energy
Biomass is the renewable organic material that comes from plants and animals.
Some of the leading biomass feedstocks include wheat, sugarcane, copra(coconut), palm nuts, canola, wood and Municipal Solid Waste (MSW).
Chemical energy stored in Biomass can be converted to other useful forms of energy such as thermal energy, electricity and fuels for transport (biofuels) through various processes:
Direct Combustion (Burning) to generate heat.
Thermochemical conversion to produce solid, gaseous and liquid fuels.
Chemical Conversion to produce liquid fuels.
Biological conversion to produce liquid and gaseous fuels.
Biomass is the only renewable energy source that can be converted into liquid biofuels such as ethanol and biodiesel. Biofuel is used to power vehicles, and is being produced by gasification in countries such as Sweden, Austria, and the United States.
By opting to switch to and promoting renewable energy adoption worldwide, we can avert the catastrophic effects of climate change ensuring an affordable and sustainable energy future for all.