Hydro Power

Blue Gold?

Hydropower includes hydro-electric power, tidal power and wave power.

Hydro-electric power

Worldwide, hydro-electric power contributes about 19% to electricity generation. In general, it involves the construction of a dam which holds back water in a river or reservoir. The water is released continuously or at certain intervals, driving a turbine at great force.

Hydro-electric power is pollution free (although shallow reservoirs in the tropics can emit large amounts of carbon dioxide and methane), but such projects can have other environmental impacts. The creation of hydro-electric power stations represents a massive intrusion to the natural environment, animals and nearby residents, and these schemes also have considerable social and economic risks. In developing countries, local populations tend to profit less from hydro-electric power as often the electricity is exported.

One option is to improve existing hydro-electric power stations and make them more efficient.

The World Commission on Dams (WCD) has developed recommendations for the ecologically, socially and economically viable expansion of hydro-electric power. WWF believes that these recommendations should be applied worldwide.

The Gold Standard, developed by WWF and other environmental organisations for projects applying the Kyoto mechanisms, also requires that the WCD criteria be adhered to.

Tidal power

This system works by using the tides in the sea to produce energy, especially in narrow river mouths or sea straits. It is not a common system and tidal power generators can be expensive to set up. However, in the long-term they can deliver cheap electricity.

The oldest tidal wave power plant was set up 1965 in the River Rance near St Malo in France with 24 10MW generators. It has functioned without fail ever since. Others in Russia, Canada and China have also been very productive.

The use of tidal power is not, however, without environmental concerns. These include disruption to the sea area and the risk of pollution to rivers.

Wave power

The third way of getting power from our waters is by using the energy created by waves. This mass of kinetic energy can be captured quite effectively. Methods include building dams or pipes for the water to go up. However, most are still quite expensive, and could also be disruptive to the environment and to other industry, such as fishing.