Water energy FAQ
The question library on water related issues
Energy is the capacity to do work and transfer heat. Work is performed when an object or substance is moved over some distance. Energy is needed to carry out processes, such as boiling water or burning candles. Energy is also the heat that flows from a hot object or substance to a cold one, when they come in contact. A clear example of this is the fact that water heats up when you put in a water boiler device.
Water, like many substances, contains two kinds of energy. The first kind of energy is called kinetic energy. This is energy that is used during the execution of processes, such as movement. Because of kinetic energy water can flow and waves can exist.
When water flows or falls, energy can be generated. The generation of energy through water is usually carried out in large water power plants, with a number of process steps and the use of several devices, such as turbines and generators. The energy in water can be used to produce electricity.
Hydroelectric power is electricity that is supplied by generating energy from falling or streaming water. Hydroelectric power is a so-called renewable energy source. This means that the source, which provides the energy, can be renewed. This is because, unlike non-renewable energy sources such as crude oil, we will not run out of water fully. It can be renewed after we have used it for energy generation.
There are several benefits to the use of hydropower. Hydropower has a moderate to high amount of useful energy and fairly low operating and maintenance costs. Hydroelectric power plants emit very little heat-trapping carbon dioxide and other air pollutants during operation. They have live spans of two to ten times those of coal and nuclear plants.
Hydroelectric power supplies about 20% of the world's electricity, and 6% of its total commercial energy.
Production of electricity from waves and tides is an option today. About twice a day in high as well as low tides, water flows in and out of coasts and estuaries. This water can spin turbines, in order to produce electricity. But analysts have been taking a closer look at this form of energy supply and they believe that tidal power can only make a tiny contribution to the world's energy supply, because of the few suitable sites, the high construction costs and the risk of equipment destruction by saltwater corrosion. However, there are a few areas with the right conditions to produce tidal power. France and Canada own the largest tidal energy facilities right now.
Several countries believe that energy can be produced from ocean thermal gradients. They have been evaluating the use of the large thermal differences of tropical oceans for the production of energy. With the thermal heat in the water they want to produce steam that can spin turbines, for the production of electricity. The thermal energy in the oceans would be converted in conversion plants, which would be anchored to the bottom of the ocean. The technology of energy production from heat stored in water has not yet been applied, as it is still in the research phase. Analysts believe that this technology will not have enough economic value to compete with other energy production technologies.
Sources: Living in the Environment, by G. Tyler-Miller and www.fwee.org