Renewable energy is green energy:
Renewable energy is the energy which is made from resources that Mother Nature replaces, such as wind, water and sunshine. Renewable energy is also called “clean energy” or “green power” because it doesn’t pollute the air or the water. In fact, wind, water and sunshine are the cleanest and most abundant sources of energy we have.
However, these abundant and natural sources of renewable energy have few shortcomings, such as unlike natural gas and coal, we can’t store up wind and sunshine to use whenever we need to make more electricity. If the wind doesn’t blow or the sun hides behind clouds, there wouldn’t be enough power for everyone. Another reason why we prefer fossil fuels like coal and natural gas over natural sources of energy is because they’re cheaper. It costs more money to make electricity from wind, and most people aren’t willing to pay more on their monthly utility bills.
The prominent sources of renewable energy are: (i) Wind power, (ii) Biomass energy, (iii) Hydro power, (iv) Solar power, (v) Geothermal energy.
(i) Wind Power - Here a wind turbine is used to make electricity. Using the wind to create electricity has been around for a long time. When the wind turns the blades of a windmill, it spins a turbine inside a small generator to produce electricity, just like a big coal power plant. To make enough electricity to serve lots of people, power companies build "wind farms" with dozens of huge wind turbines. Wind farms are built in flat, open areas where the wind blows at least 14 miles per hour.
(ii) Biomass Energy - Biomass energy uses natural materials like trees and plants to make electricity. It can also mean waste products like trash. Biomass means "natural material." When biomass energy is burned, it releases heat – just like the wood logs in your campfire. Some of the common material used includes: (a) Leftover wood from sawmills. (b) Leftover paper and wood waste from paper mills. (c) Corn stalks, corn cobs and seed corn from farms. (d) Paper and cardboard that can’t be recycled in other ways. (e) Fast-growing crops and trees etc.
The philosophy behind biomass energy includes:
* Growing energy crops,
* Turning garbage into energy,
* Cow power or power from animal waste.
(iii) Hydro Power - A hydro power plant uses river water to make electricity. In fact, people have used water power for more than 2,000 years. In modern day, people built dams to control the power of the big mountain rivers. Workers can change the amount of water flowing through the dam depending on the weather and how much electricity people need.
(iv) Solar Power - “Solar” is the Latin word for “sun” – and it’s a powerful source of energy. In fact, the sunlight that shines on the Earth in just one hour could meet world energy demand for an entire year. We can use solar power in two different ways: (a) as a heat source, and (b) as an energy source.
Today we use solar collectors for heating water and air in our homes. We can also use solar energy to make electricity. The process is called photovoltaics. It’s difficult and expensive to make a lot of electricity using photovoltaics – the panels cost a lot, and a lot of open land is needed.
(v) Geothermal Energy - The hot lava from a volcano and the hot steam from a geyser both come from underground heat - and we can use that same type of heat in our homes. The system pumps a liquid through the pipes to absorb the heat and brings it back indoors. A device called a "heat exchanger" takes the heat from the liquid and uses it to heat the air inside the home. A geothermal system can cool your house during the summer, too! It just works in reverse, absorbing the heat from the air inside your home and moves it back into the earth. A geothermal heater is also very energy-efficient. Almost none of the energy used is wasted, so it helps keep heating bills very low during the winter.