Tidal stream power

Tidal stream power is electricity made from the tidal movement of water. A tidal stream generator is a machine that extracts energy from moving water in tides. Tidal stream generators draw energy from water currents in much the same way as wind turbines draw energy from air currents.

Tidal stream power is the cheapest and the least ecologically damaging among the three main forms of tidal power generation.^[1]

Tidal stream power is a relatively new technology. It was first conceived in the 1970s during the oil crisis.^[2]

The potential for power generation by an individual tidal turbine can be greater than that of similarly rated wind energy turbine. Water is about 800 times the density of air. So, water pushing against a turbine can provide much more power than air pushing against a similar turbine at the same speed. Also, the lowest water speeds needed for an economic power project is lower than the wind speed needed for a wind turbine project.^[3] In practice, the tide must move at speeds of at least 2 knots (1 m/s) even close to neap tides to be a source of power.

As with wind power, selection of location is critical for the tidal turbine. Tidal stream systems need to be located in areas with fast currents where natural flows are concentrated between obstructions, for example at the entrances to bays and rivers, around rocky points, headlands, or between islands or other land masses.

1. ↑ "Tidal power". Archived from the original on 23 September 2010. Retrieved 1 November 2010.
2. ↑ Jones, Anthony T., and Adam Westwood. "Power from the oceans: wind energy industries are growing, and as we look for alternative power sources, the growth potential is through the roof. Two industry watchers take a look at generating energy from wind and wave action and the potential to alter." The Futurist 39.1 (2005): 37(5). GALE Expanded Academic ASAP. Web. 8 October 2009.
3. ↑ "Surfing Energy's New Wave" Time International 16 June 2003: 52+. http://www.time.com/time/magazine/article/0,9171,457348,00.html Archived 2012-01-30 at the Wayback Machine