Most forms of renewable energy are far more connected to each other than they seem. The Law of Conservation of Energy states that energy can neither be created nor destroyed. Because of this, the different renewables available for harvest derive from similar sources. For example, take wind and solar power. One absorbs photons emitted to the Earth from the Sun, while the other generates electricity by having flowing gases spin a turbine. However, wind on a global scale is formed directly from the Sun. The Sun’s rays reach the poles of the Earth on a much more slanted angle than the equatorial regions, causing a pressure gradient between the hot equator and cold poles. The heated air rises at the equator and sinks at the poles, and the pressure creates global wind circulation. Another form of energy, which is not quite as popular, is tidal power. Tides are generated by the gravitational relationship between the Earth, Moon, and Sun, thus giving tidal energy a similar source to solar and wind power.
Generating electricity from waves can be a difficult process. All forms of hydropower take advantage of the kinetic energy that comes from falling water. Tidal power is a form of this, drawing energy from the rising and sinking of the Earth’s tides. It is the only form of power generation that harnesses energy from the Earth-Moon gravitational forces. IEC/TS 62600-200 ED. 1.0 EN:2013: Marine energy Wave tidal and other water current converters Part 200 Electricity producing tidal energy converters Power performance assessment provides recommendations for evaluating the power performance of an electricity-producing tidal energy system.
There are three forms of tidal energy generators: tidal streams, tidal barriers, and tidal lagoons. Tidal streams generate energy from a fast-flowing body of water formed by tides, and tidal barriers use a barrage dam that creates a pool during high tides, which it then releases through a turbine as the tide lowers. Tidal lagoons are very rare and draw energy from tides changing in a lagoon. The standard provides an understanding of the energy output of the turbines in these different types of tidal power generation. It details guidelines needed to properly use tidal energy converters (TECs) to generate electricity by tides for implementation in the grid.
Tidal power is far more predictable than energy generated by solar and wind, but it has its limitations. One significant drawback is its environmental impact. Renewable forms of energy are ideal to use because they often do not release greenhouse gases in the atmosphere. Tidal power and other forms of hydropower do not burn fuel to generate electricity but can release the more-potent greenhouse gas methane into the atmosphere if the vegetation growing near any dam is disturbed. Building of dams and other infrastructure needed for hydropower generation can cause marine habitat destruction. Occupying space in bodies of water can also take away from other potential uses of that area, such as designation of fishing zones or marine-protected areas. This will require management of the installation of hydro- and tidal turbines if they are vastly implemented as a source of electricity. Tidal power, while not widely used today, has great potential for future use. There is a large amount of energy that is constantly being brought to the Earth. These forms of natural energy, coming from sunlight, wind, tides, and waves, are all connected and, if properly taken advantage of, can provide society with a continuous stream of clean energy.
Other forms of hydropower electricity generation are covered in the standard IEC/TS 62600-100 ED. 1.0 EN:2012: Marine energy – Wave, tidal and other water current converters – Part 100: Electricity producing wave energy converters – Power performance assessment.