Definition of Renewable energy
Renewable energy is energy gotten from natural resources or processes that are constantly replenished over a short time as they are being used. The sources of renewable energy are all around us in abundance such as hydro, wind, sunlight and so on.
Renewable energy sources have a low or zero carbon footprint as there is no release of pollutants like carbon dioxide thereby, being very environmentally friendly to use and helping to tackle climate change. Some renewables can also cause damage to natural habitats and wildlife and cause deforestation e.g., hydroelectric energy and bioenergy. They are also cheaper in most countries and perform up to three times more efficiently than non-renewables.
Renewable energy has been in use since the beginning of time like the use of the wind’s power to sail boats in seas and to run windmills for the grinding of grains. Also, the use of sunlight to kindle fire and the use of wood for cooking, heating and burning.
Now, technology has led to innovations in renewable energy at small and large scales like the invention of solar panels used on rooftops to provide power to the grid and the building of giant offshore wind farms. This has made renewable energy more efficient, widespread and affordable.
Various sources of renewable energy:
Wind energy has been used for ages for sailing boats, powering windmills, etc. Wind energy utilizes the kinetic energy of moving air through the help of huge wind turbines on land (onshore) or in the sea (offshore). The use of wind energy has evolved with the help of technology for more effective production of electricity. Electricity is generated by spinning the blades of the wind turbines whereby the kinetic energy produced is converted to electric energy through a series of processes.
This renewable energy is the most popular and abundant of all. Advancements in technology have brought about the invention of solar technologies which function by converting sunlight into electrical energy using mirrors or photovoltaic panels for concentrating the solar radiations in a joint physical and chemical reaction known as the photovoltaic effect.
Solar energy can provide electricity, natural lighting, heating or even cooling depending on the applications and intended use. Though the cost of manufacturing solar panels has increased through the years, it is still considered the cheapest form of electricity and does not produce pollutants or greenhouse gases.
This energy can be derived from rivers or reservoirs by their respective hydropower plants. It utilizes the energy of water as it moves from a higher elevation to a lower elevation with the help of dams and turbines. Hydropower is the largest source of electricity amongst the other renewables. Hydropower provides multiple uses like energy supply, water for irrigation, drinking water, navigation services, flood and drought control, etc. Their application also depends on a stable rainfall pattern.
Geothermal energy is gotten from the thermal energy derived from Earth’s heat. With the use of wells and other means, this heat is extracted from geothermal reservoirs for use in generating electricity, heating and cooling buildings, etc. The two types of geothermal reservoirs are the hydrothermal reservoirs that are naturally adequately hot and permeable and the enhanced geothermal systems that are adequately hot by hydraulic stimulation.
This source of energy is produced from organic matter known as biomass which includes charcoal, wood, agricultural waste, dung, garbage, organic waste streams, etc. The combustion of these materials converts them into energy that can be used for cooking, lighting, space heating and generation of electricity. The burning of this biomass creates energy that leads to the emission of greenhouse gases.
Ocean energy describes the use of specialized technologies to harness energy from ocean currents, tides or wave motions. The thermal and kinetic energy of the water waves and current is used for different applications such as the production of electricity or heat.
The tide is governed by the constant gravitational pull of the moon, making it reliable and a relatively good source of energy. Some ocean tidal energy activities, such as tidal barricades located in ocean bays, can be of harm to wildlife.