This week we’re going to take a closer look at one of the oldest and most widespread renewable energy resources – hydroelectric power. Hydropower utilizes the enormous potential energy of water by funneling it through turbines connected to generators, converting the potential energy into kinetic energy, which is then converted into electricity via spinning magnets.
Hydropower is used in 150 countries, with the highest usages in Asia-Pacific nations which are rich in water and possess the right topography. Electricity generated from water accounted for around 16% of global power consumption by the end of 2010, and the use of this renewable resource grew by more than 5% in the period from 2009 to 2010 (Worldwatch Institute). The average cost of hydropower from a large (>10 MW) powerplant at that time was $0.03 to $0.05 per kilowatt hour, and it remains very low today compared to other power sources.
China leads the world in the use of hydropower with an estimated hydropower generation capacity of around 230 gigawatts at the end of 2011 (Reuters). Global hydropower use is said to be around 721 terawatt hours (DailyKOS). China added 16 GW to their capacity in 2010, with plans and construction underway to add a further 140 GW by 2015. An increase of this size would necessitate the building of seven more dams the size of the Three Gorges dam, which is currently the world’s largest hydroelectric generation facility.
According to the sustainability research organization Worldwatch, only four countries out of the 196 on earth generated 100% of their power from hydroelectricity – Paraguay in South America, Lesotho in Africa, Bhutan in Asia, and Albania in Eastern Europe. Fifteen nations generated over 90% of their electricity from hydroelectric sources, with New Zealand and Norway producing the most of their power per capita from this renewable resource.
History of Hydroelectric Power
The energy of flowing water has been utilized by man for many thousands of years. The first recorded use of a waterwheel to grind grain was by the Ancient Greeks, who invented the Perachora wheel in the 3rd century BC. These simple devices transferred the energy of flowing water into mechanical energy to grind grains for food production.
Hydroelectric power was first created in the late 1800s when newly invented electric generators were coupled with waterwheel technology that had been used for thousands of years for mechanical means. The world’s first hydroelectric generator was built in Cragside, Northumberland, England, by William George Armstrong to provide power for a solitary light bulb in his art gallery.
The first small-scale domestic hydropower generation took place in the US in 1880 in a chair factory in Grand Rapids, Michigan. Our first hydropower utlility plant opened on the Fox River near Appleton Wisconsin in September 1882, with other plants springing up on the East Coast of the US over the next decade, until there were over 200 hydropower plants in the United States in 1889.
The Hoover Dam, built in 1936, generated 1,345 megawatts and was the largest generator of hydropower in the world until the Grand Coulee Dam in Washington State went online in 1942. The enormous amounts of electricity it generated went to power the production of plutonium as the US developed the first atomic weapons that brought World War II to a close.
How does it work?
Hydropower is generated via several different methods. Conventional power is produced via damming a river, and funneling the river water from the resultant reservoir through turbines to generate electricity. Pumped storage generation is a variation of conventional hydropower where water is pumped through a system of reservoirs with different elevations in order to produce more power in times of peak need.
Run-of-the-river hydro systems produce power without reservoirs, in that generators and turbines are placed directly in the water flow. These systems can only produce electricity when the river is flowing at sufficient levels. Other types of hydrogeneration include underground facilities where tunnels are used to drain water from one source down beneath the earth through generating facilities and out into another waterway. Tidal fluctuations can also be used to generate power; this renewable energy resource will be covered in a future Spotlight column.
Where is Hydropower Successfully in use?
More than 50% of the US hydropower capacity lies on the West Coast in CA, OR, and WA. The Grand Coulee Dam still puts out 29% of the total hydropower in the US.
The biggest hydroelectric project in the world is the Three Gorges dam in China. This facility produces 22.5 GW of electricity. It is estimated that the Three Gorges Dam will pay back its construction cost within 5-8 years after it reaches full capacity in May of this year. This dam inundated a total of 244 square miles.
Coming in second is the Itaipu Dam in Brazil, which provides 14 GW of electricity for that nation and its neighbor Paraguay (which you will remember received 100% of its electricity from this dam in 2010). The Itaipu Dam flooded almost twice as much land, at 520 square miles.
What Negative Impacts are There?
Hydropower is one of the most environmentally-friendly means of generating electricity – as long as you discount the terribly adverse environemntal effects of the dams that store the water. Other than the obviously negative impact of inundating large swaths of land, damming rivers causes drastic changes to river temperatures, silt levels, flood characteristics, water chemistry, and habitat loss. Effects can be felt thousands of miles away where river deltas once deposited lush loads of sediment, devastating entire ecosystems.
In addition to negative environmental impacts, construction of hydropower dams use massive amounts of concrete. The Three Gorges Dam required over 27 million cubic yards of concrete, and 463,000 tonnes of steel – materials which required substantial amounts of greenhouse gases to produce and install.
Nonetheless, hydropower still remains the cleanest, most efficient power source. This might change in the near future though as solar technology advances and the efficiency of that nearly limitless and ubiquitous power source increases.
Do Ski Areas Use Hydropower?
Aspen, Colorado has more than just beautiful women. In its early days, the city was entirely powered by hydroelectricity, and its citizens enjoyed what many called the best-lighted city in the American west. In 1885, Aspen was the first American city west of the Mississippi to run electric lights on streets and in homes and businesses – all powered by hydroelectric generation. In fact, Aspen generated enough power to be able to sell it to other communities until the city’s plant was scrapped in 1958.
As of a few years ago, Aspen still got a sizeable chunk of its power from hydrogeneration (36.8%), but most of that is imported from outside of the city. Nevertheless, Aspen still hosts three operating microhydropower generation systems – one on Maroon Creek that puts out 450-500 KW, a 20 KW system in the basement of the Mountain Chalet in Snowmass, and a 40 kW system at a private homeowner’s property.
Snowmass Ski area performed some crafty reverse engineering in 2005 and retrofitted their snowmaking system into the area’s fourth hydropower system. Since the snowmaking system already consisted of a network of connected pipes, pumps, and reservoirs, all they had to do was add a turbine and a generator in order to turn it into a hydroelectric plant. In a small building on Fanny Hill, a Pelton Wheel creates 115 KW of electricity from water funneled from a pond located about 800’ higher up the mountain, fed by Brush Creek.
In January, the Aspen Times ran an excellent two-part story on what is powering Aspen. Read the story here. A large hydro project by the name of “Castle Creek” hydro is on the books for Aspen, and it has proved to be divisive to the environmental community. The proposed energy center would produce about 8% of Aspen’s electricity demand. Already, 75% of Aspen’s electricity comes from renewable resources, so a further 8% would give it a sizeable boost. As the venerable Hunter S. Thompson realized when he ran for sheriff in 1970, Aspen likes to position itself as a trend and policy setter for the national political stage, so it’s worth paying close attention to what goes on there.
Up north in Canada, Whistler has also jumped on the hydropower train. The Fitzsimmons microhydro power generation facility on the mountain there produces ~32 GW of electricity – which is said to be equal to Whistler-Blackcomb’s annual consumption. Clif Bar awarded Aspen it’s Golden eagle award in 2010 for adopting this power generation scheme.
Hydro dams are not without controversy. A growing number of them are becoming obsolete across Northern california and the Pacific Northwest. Check out this incredible timelapse of a dam being removed in Washington State:
Another film worth watching is “Chasing Water,” in which filmmaker Joe McBride attempts to follow the Colorado River to its outlet in the Pacific Ocean, and in doing so explores the myriad issues of damming mighty rivers for irrigation and hydropower.