Thursday, February 21, 2013

Global hydropower consumption and growth

Hydropower is one of the oldest and most reliable energy sources. Reliable in this case means not suffering from variability in generation like this is the case with solar and wind energy. Still, even despite being very reliable source of energy hydropower sector isn't growing as fast as solar and wind do and is pretty much stagnating when compared to solar and wind in much of the world.

The recent Worldwatch report says that hydroelectricity currently accounts for 6-7 percent of primary energy consumption. Among regions, South and Central America are the most dependent on hydroelectricity generation relative to total energy use. Not surprisingly, hydropower is the least important energy source in Middle East, but this hasn't stop this region to achieve a record growth in hydroelectricity in 2011, at approximately 22 percent. The North America (US and Canada) also experienced significant growth in hydroelectricity generation in 2011, at around 14%.

Though there are more than 150 countries in the world that generate some form of hydropower, much of the total hydropower capacity is still concentrated among five countries, with the global leader being China with 212 GW , followed by Brazil (82.2 GW), the United States (79 GW), Canada (76.4 GW), and Russia (46 GW). China's Three Gorges Dam is still the largest hydroelectric power plant in the world.

Hydropower is environmentally friendlier than fossil fuels but if not planned properly large hydro projects can cause massive environmental damage (the damning of rivers to create reservoirs for plants can cause major adverse effect to many nearby ecosystems). Also, large hydro projects have led to the displacement of thousands of people ( like the well known case with the construction of Three Gorges Dam).

Hydropower still remains one of the most cost-effective energy sources with costs of 2-13 U.S. cents per kilowatt-hour for existing grid-connected hydropower plants and 5-10 cents per kilowatt-hour for new hydro plants. The global hydropower consumption reached 3,498 terawatt-hours at the end of 2011.

A relatively modest 25 GW of new hydropower capacity was added in 2011, representing a decline in comparison to previous years, with China, Vietnam, Brazil, India, and Canada accounting for 75 percent of the added capacity.