Hydro power is the energy produced from water. Typically, hydro power comes from a hydro-power plant as shown to the left, but there are other forms such as tidal energy. Tidal power, as it sounds, uses the ocean's waves to generate electricity. But how does your average hydro-power plant work? A controlled flow of water from a higher reservoir to a lower reservoir flows throughout the plant. First it goes through the control gate, which regulates the amount of water to flow through. It then flows through the penstock, which also helps regulate the rate of flow, to the turbine. The waters flow causes the turbine to turn and generate electricity, which then heads through the electric companies to your house. So now that you know how it works, why is hydro energy so convenient? Well for starters, water (H2O) is the most abundant compound on earth. About 70% of earth is covered in water which comes out to around 326,000,000,000,000,000,000 gallons. Now is it possible to convert all of that into energy? The answer is no. But between hydroelectric plants and tidal plants, there is a lot of potential energy. And since these two systems can reuse the water the source is renewable. In addition to the renewability, hydro energy is a good potential energy source because it doesn't really give off any harmful by-products such as coal would. For all of these reasons, I believe hydro energy should be a strong contender as a main energy source in the future.