Hydropower is energy derived from flowing water. More than 2,000 years ago, the ancient Greeks used waterpower to run wheels for grinding grain; today it is among the most cost-effective means of generating electricity and is often the preferred method where available. Hydropower plants (HPPs) convert the power of flowing water to electricity. The amount of energy in the water flow is determined by the flowing or falling rate of water. In large rivers, the water contains massive amounts of energy. Or when the water falls from a very high point, substantial amounts of energy can be generated. In both approaches, the water is channeled to a turbine through canals or pipes and rotate turbines that generate electricity. The turbines are connected to generators which convert mechanical energy to electric power.


In Norway, 99% of electricity comes from hydropower. The world’s largest hydropower plant is the 22.5 gigawatt Three Gorges Dam in China. It produces 80 to 100 terawatt-hours per year, enough to supply between 70 million and 80 million households. 24 countries in the world derive 90%, and 63 countries derive 50% of their total national power output from hydropower plants.


Small-scale micro-hydropower projects can make a big difference to communities in remote locations. The basic principle of hydropower is using water to drive turbines. Hydropower plants consist of two basic configurations: with dams and reservoirs, or without. Hydropower dams with a large reservoir can store water over short or long periods to meet peak demand. The facilities can also be divided into smaller dams for different purposes, such as night or day use, seasonal storage, or pumped-storage reversible plants, for both pumping and electricity generation.
Hydropower without dams and reservoirs means producing at a smaller scale, typically from a facility designed to operate in a river without interfering in its flow. For this reason, many consider small-scale hydro a more environmentally-friendly option. HPPs are the only resource where energy can be stored, as the water stored in a reservoir can produce power when and as needed.


Hydropower is one of the most potentially substantial form of renewable energy resources in Turkey. The country has a gross hydropower potential of 433 billion kWh/year, a technical potential of 216 billion kWh/year, and economic potential of 164 billion kWh/year (DSİ, 2013). Based on these values, Turkey possesses 1% of total global technical hydropower potential, and 16% of European economic potential, second in Europe after Norway.

In Turkey, hydropower plants have been erected across 26 main river basins. Euphrates and Tigris are two of the major ones, and the Southeast Anatolian Project (GAP), implemented in this region, is Turkey’s largest power generation, irrigation and regional development drive. When completed, GAP will comprise 22 dams and 19 HPPs, generating 27 billion kWh/year of power with an installed capacity of 7476 MW. Also, 1,82 million hectares of farmland will gain access to irrigation.
Turkey’s technical hydropower potential corresponds to 1,5% of global and 17,6% of European technical potential.



Hydropower Plants (HPPs) do not drain rivers. They generate electricity by diverting some (never all) of the water away from the river to a power plant over a distance through a transmission line. After rotating the turbine, the water is discharged back to the riverbed, without impairing its qualities. No pollution or loss occurs during this process. On the contrary, the portion of the water stream used in the HPP is released back into the riverbed after filtering out any waste materials that it may contain. In this sense, a HPP is the windmill of our time, except it turns a turbine instead of a millstone.


The streams are not sold in any sense of the word. Operators who wish to build a HPP are granted authorization to use the water for 49 years, based on a Water Usage License agreement with the DSİ. The agreement clearly provides that the operator may use the water solely for generating power, and must release the water back into the riverbed upon request by DSİ for any reason, without indemnification.


Building HPPs on all streams is not technically possible or economically viable. After detailed studies by the agencies concerned, only those locations which match the requisite technical, economic, environmental and social specification are selected as a potential HPP site. Because of these reasons, today it is possible to build HPPs for a total capacity of 165 billion kWh compared to 433 billion kWh, which it is possible to generate if HPPs were erected all the way from the springing point through the disemboguement point. The DSİ ensures that HPPs are not authorized at locations where it is not technically and economically viable to do so.


Paid-for HPP licenses have been granted for 25.061 hectares of forest land across Turkey. This area corresponds to less than 0.1% of our total forest coverage. In Rize, where HPP projects are particularly numerous, paid-for licenses have been granted to HPPs, for 135 hectares of forest land, corresponding to 0.08% of total forest coverage in Rize. Moreover, HPP operators are required to commit to planting not less than 5 times the number of trees that they have damaged, in species which are higher in economic value then the ones that have been removed.


Hydropower is the cleanest way to produce electricity. Because they do not cause carbon emission, HPPs should be supported to counter global warming and climate change. HPPs are clean energy producers that use the power of water streams and produce no waste as a result of power generation. As an example, a 25 MW HPP on a river generates 80 million kWh of green energy per year, corresponding to preventing emission of 47.000 tons of carbon dioxide or removing 9.000 vehicles from the roads, which equals the amount of clean air generated by approximately 3 million trees. In other words, contrary to the misperception that “HPPs cause great harm to the environment,” HPPs are environment-friendly facilities.