Waterpower station is a power-plant which changes the energy of water into electricity. The basic elements of such construction are water turbines, electrical generators and transformers connected to the electricity network. The disadvantage of hydroelectric power station is a limited number of locations in which they can be built.
The development of technology in Poland
According to the analysis made in the course of establishing a RES national action, hydroelectric potential of our country is relatively small. With the exception of mountainous areas, for most of the land available for managing or construction, the differences in water levels will be relatively small.
Hydroelectric power stations in Poland
Polish hydroelectric resources are estimated at 13.7 TWh per year, of which 45.3% falls on the Vistula River, 43.6% on the basin of the Vistula and the Oder, 9.8% on the Oder River and 1.8% on Pomerania’s rivers. Before Second World War II hydroelectric power stations, placed on the coastal rivers only, were providing electricity for marine port in Gdynia, Kartuzy and Gdansk with its surroundings. This fact gives an idea, how big potential hydroelectric power plants are holding.
To the 80s of the last century there was a common view that hydro is the “cleaner” energy source. It means that are the least harmful to the environment. It was believed that impurities do not enter to the atmosphere during electricity production of the hydroelectric power station and the noise is low level (due to the low turbine speed). However, recent studies showed, that reservoirs can be a source of methane emissions . The amount of emitted methane may vary considerably, depending on local conditions (mainly the amount of organic matter accumulation, temperature, presence of methanogenesis inhibitors).
Construction of the power plant significantly alters the ecosystem and the surrounding landscape. To achieve a high level of water, it is often necessary to flood large areas of river valleys. This entails resettlement of people living on this lands and induces destruction of local fauna and flora. The fast, swift river is replaced by reservoir filled with stagnant water. This causes growth of a completely different organisms. Additionally, a large tank has much greater evaporation and changes humidity on a relatively large area. After leaving the dam, swift river flows very slow usually. This reduces the aeration of water. Furthermore, lack of periodic flooding leads to siltation of reservoir bottom.