The Hydropower of Tomorrow

Hydroelectricity is a renewable, non-polluting energy. It does not cause any greenhouse gas emissions or produce any toxic waste. It currently represents almost 20% of global electrical capacity and has development potential of 3 times its current level. While the investment required and the human and environmental impact weigh heavily on large dam-building projects, the future seems promising for small hydro.

Hydropower's Advantages Mean that it Has a Promising Future...

Hydropower has low operating and maintenance costs. Its life cycle is extremely long; and it is highly reliable in operational terms because it is a tried and tested technology. In France alone, of the sixty-odd large dams still in use, many were built before 1960. The oldest, located in Nievre, was opened in 1858.

Hydropower can be used to meet electricity requirements at times of fluctuating demand.

Hydropower can also be used to meet electricity requirements at times of fluctuating demand. Although it is not possible to store electricity on a large scale, water can be contained in large reservoirs using dams or dikes. This is a simple, easy way to store potential energy. What's more, a hydroelectric power plant can reach maximum capacity within a few minutes. By comparison, a thermal power plant takes several hours to reach full capacity, and a nuclear power plant takes four times longer than that.

... but Significant Obstacles to Overcome

On the face of it, hydropower seems to have everything going for it. But building colossal dams and retaining huge amounts of water have human and envionmental consequences.

   • If these consequences are not considered, a dam's construction can have serious environmental implications. For instance, it can hinder the migration of some aquatic species, affect water tables, shake up suspended matter and sediment, and cause noise pollution. What's more, the environmental structures in place are disrupted upstream by reservoir construction and downstream by the drop in waterflow. It can take several decades to restore a sustainable environmental balance to the area. In any case, long and costly studies are necessary to measure the environmental impact of building a dam.

   • Apart from its environmental impact, creating a reservoir also affects human activity. It is sometimes necessary to displace people or economic activities (such as farming)- upstream to create a reservoir and downstream because the areas bordering the river dry out.

Large and medium-sized dams are also very expensive. Governments increasingly try to obtain funding from private sources or from large international organizations such as the World Bank to finance these projects; but because many believe that they take too long to pay off and become profitable, hydropower projects have difficulty attracting investors.

The future of hydropower therefore depends to a large extent on the persuasiveness of states and on potential public-private agreements.

Energy can be produced from waves.

True. Using wave energy is a more environmentally-friendly way of using hydraulics on a smaller scale. The largest wave energy project in the world is off the coast of St. Ives in Cornwall. Known as Wave Hub, this facility will be deployed on the seabed and an array of devices will be connected to it to produce energy from waves. One day, this facility could generate 20 megawatts of electricity.

Future Opportunities

Hydropower still ranks first among renewable energy sources and it remains essential. Hydroelectricity currently accounts for almost 90% of renewable electricity production worldwide¹.

The planet has yet to achieve its full hydroelectric potential- at about 15,000 TWh, its potential is 3 times higher than current levels².

In the future, smaller scale, more environmentally friendly ways of using hydropower may be developed. These include small hydro projects which use natural river currents and waterwheels (Noria) to produce energy, or tidal and wave energy. In this case, the focus is on using water's natural cycle rather than changing it to produce energy. The techniques used are less invasive, therefore more environmentally friendly.

All over the world, there are a number of ways in which production could be developed, by:

   • Adding new turbines at existing hydroelectric facilities to step up production from 10 to 50 MW 

   • Building new dams

   • Developing small hydro (SH) plants producing 0.1-10 MW

   • Upgrading existing water wheels (pico hydro power, with capacity of 10-100 kW) as is the case with many current and completed projects (such as the Chappes water wheel in Northeastern France).

[1] http://www.enr.fr/
[2] The World Water Assessment Programme (WWAP)