Renewable energy technologies generate energy in an environmental friendly way, and usually from sources which can be replenished. This technology involves natural phenomena such as water, sunlight, tides, wind, geothermal heat and plant growth. Using renewable energy is also a strategy to ensure energy security. The renewable energy technologies include:-
Electricity generated from the gravitational falling or flowing of water. It is the most used form of renewable energy accounting for 16% of the total world’s electricity production. This is due to the low cost of production making it more competitive than the other sources of clean energy. The production of hydroelectricity has no direct waste and has a minimal emission of the greenhouse gases than the fossil fuel energy plants.
The term biogas refers to the mixture of gases produced by the breakdown of organic matter in the absence of oxygen by anaerobic bacteria. It can also be produced by the fermentation of materials which are biodegradable such as sewage, manure, plant material and municipal waste. The gas produced are primarily methane and carbon dioxide but also in trace amounts are hydrogen sulphide and moisture. The gases produced can be oxidized (combusted). This allows biogas to be used as fuel for any heating requirements. Biogas has a great benefit as it reduces the global climatic change by using waste in the production of energy.
Simply the conversion of moving air into useful energy form. Wind turbines, pumps and mills are used in this technology. Wind harnessing farms consist of hundred individual turbines connected to electric power transmission grid. Onshore winds are inexpensive sources of electricity than fossil fuel plants. Wind power is a clean source of electricity since it produces no emissions and uses a small piece of land.
Heat and light energy from the sun are harnessed using devolved technologies such as solar photovoltaic, solar heating, solar thermal electricity and artificial photosynthesis. These technologies use either active or passive solar depending on the way they harness, convert and distribute the solar energy. Large areas of sunlight are concentrated by lenses into a small beam then the photovoltaic converts the light energy into electric current using photoelectric effect.
This is the heat energy stored and generated in the earth. It originates from the original formation of the planet earth and also from radioactive decay of matter and minerals. Geothermal power is friendly to the environment and also cost effective. However, it is limited to areas near tectonic plate boundaries. The difference in temperature between the earth’s surface and its core leads to a continuous heat conduction from the core to the surface. It comes in two forms; either vapor dominated or liquid dominated form.
This is a form of energy obtained from the tidal waves in oceans. It is from water and hence can be defined as hydro-power that transforms ocean tides into electricity. Waves are more predictable as compared to other forms of alternative energy such as winds and solar power, giving it a high potential in electricity production. However, the tidal power is not yet widely used due to high cost of production and the limited availability of potential sites. It’s beneficial since the tides are not exhaustible and are there to be.