To know abc of renewable energy, let’s start with the term energy first. Energy is the property of objects which allows them to change their physical states. It should be noted that energy cannot be created nor destroyed. It can only be changed from one state to other. For example, car uses diesel energy and converts it into motion. Meanwhile, heating and friction losses are produced. Here, heat and friction losses are form of energy. Thus energy cannot be created; it can only be transferred from one form to other form.
Car is one example; there are plenty of examples which we use in our day to day life. We human being use natural resources process them through suitable processing plant and utilize as per our needs. We try to reduce our efforts to do daily tasks. Over the time, we have invented better technologies to use available natural resources. Electricity is one of the important inventions in human history. It has changed our life to greater extent. It has extended our working hours, lifestyle and everything. Today, electricity can be treated as fourth basic need of human being after food, clothing and shelter. To satisfy this need, we need to generate more power from generating stations. This ultimately results in more number of generating stations and more use of natural resources. Fossil fuels are major sources of electricity generation stations. But there is problem with them; their availability is limited in nature. Actually, fossil fuels are formed by natural decomposition process of buried organisms. It takes millions of years to make such fuels from dead organisms. In other words, as we use them; one day, they will be exhausted. Fossil fuels are detrimental for environment as they produce polluted air and greenhouse gases.
To prepare for the day when all fossil fuels will be exhausted, we have developed alternative techniques of generating electricity. These techniques are known as renewable techniques and the field which deals with such issues is known as renewable engineering. In this, we use those natural resources to generate electricity which can be given back to the nature after using it. For example, Wind turbines are driven by natural wind pressure. The wind having high speeds rotates the blades which are coupled to electric generator. Wind is passed through the turbine blades only. It is not used directly to rotate the blades. By this way, wind is given back to nature and it can be again used after some time at some other location. Renewable actually mean ‘which can be reused again and again’. Examples of renewable energy sources are sunlight, Wind, water, rain drops, internal heat of earth (geothermal), tidal waves, etc.
Hence, in simple words renewable energy is the energy which can be reused again and again.