In some parts of the world, energy comes roaring up out of the ground or rolling across the ocean – for free!
One form of this energy is gathered from boiling water and steam. The rocks deep below the surface of the earth are very hot, sometimes as hot as 600 °C. This is about five times hotter than boiling water. If underground water trickles into these hot rocks, it quickly turns into steam. The steam takes up about 4,000 times more room than the water. The steam forces its way into cracks in the rocks and sometimes finds its way to the surface. The steam can be piped into an electricity-making machine called a turbine. The steam turns wheels in the turbine, which helps a generator to make electricity.
Movement in the oceans also releases huge amounts of energy. People have invented several ways to use this energy. One way uses the power of the rising and falling tides. To capture this energy, a dam is built across the opening to a bay. At high tide, the dam is closed to hold water in the bay. At low tide, the water can be released. The flowing water spins wheels inside a turbine to help make electricity.
Picture Credit : Google