Hydropower plants use the potential and kinetic energy of water to generate electricity:
The European Union adopted the following breakdown of hydropower plants:
- small hydro plants: installed capacity to 10 MW
- large hydro plants: installed capacity above 10 MW
In technical terms, we can distinguish:
- run-of-water power plants
- power plants on reservoirs with periodic flow regulation
- plants in a compact cascade
- pumped storage power plants and power plants with pumping units
Hydropower in Poland:
According to the data of the Energy Regulatory Office, at the end of 2012, 770 hydropower plants were in operation in Poland with a total capacity of 966 MW. Compared to 2011, there was an increase of nearly 15 MW. For years, in many EU countries, in the whole world and in Poland, water has been the dominant source of energy produced from renewable sources.
History, potential and perspectives of the development of hydroelectric power plants in Poland:
Most Polish hydropower resources are concentrated in the area of the Vistula River, particularly its right-bank tributaries. Favourable conditions for the construction of small hydropower plants exist in the Carpathians, the Sudetes, the Roztocze, as well as on coastal rivers. The potential of the Oder is also important. It has a potential for power engineering provided that the river is dammed up. This can be done using dams or weirs. Such damming of rivers with large flows (such as the Vistula) require the construction of large facilities (reservoirs), which on one hand is used to regulate water levels in rivers e.g. in the case of a flood, but on the other hand causes changes in the river ecosystem. This is not the case of small hydropower plants (SHP), which do not require the construction of high dams (a relatively small weir, damming water to a height of about 1.5-2 m, is enough), and thus minimising the impact on the environment. A small hydropower plant does not require the construction of a reservoir (it uses only the amount of water that flows at a given moment in the river).
Small hydropower plants come from water wheels working once on the rivers, used to power mills, saw mills, fulling mills, granaries, etc. Their use dates back to the fifth century BC, and on the Polish lands they are known since the thirteenth century. Over time, due to the low efficiency of water wheels, they were replaced by water turbines. Installing a water turbine in place of a water wheel allowed to obtain several times more power from the same water conditions. However, turbine speed is too high to use it directly to drive machines. Thus, the turbine generates electricity.
Unfortunately, the process of replacing water mills with power plants was stopped in Poland after the war. As indicated in the table below, in the 1930s in Poland there were about 8,000 plants which used water power. Today, there are only 770 and more than 81% of the existing technical potential of water in our country is left unused.
European Small Hydropower Association's (ESHA) Guide on How to Develop a Small Hydropower Plant. Investor Guide (published in 2010) indicates that the use of technical potential of small hydropower plants in European countries is on average about 47%, and in Poland only 19%. In this respect, Poland holds one of the last places in Europe.
According to ESHA's data, in European hydropower sector it is possible to increase the annual production from about 41 TWh (data from 2006) to nearly 80 TWh by modernising existing hydropower plants and constructing new ones. In Poland, there is a possibility of more than a fivefold increase in production in hydroelectric power plants up to 10 MW - from 900 GWh (data from 2006) to more than 5 TWh in the future.
In policy documents, such as the Poland's Energy Policy until 2030 and the National Action Plan in the Field of Renewable Energy, hydropower development is expected to be mainly based on the use of existing damming to produce electricity. The list drawn up by the National Water Management shows that in Poland there are over 14,000 damming structures (with a damming height above 0.7 m) owned by the State Treasury. The degree of utilization of these damming structures for hydropower is only 4.5%.
Source: Presentation "Survey of Damming Structures, M. Kowalczyk, KZGW, Today and Tomorrow of Hydropower in Poland and the EU" Conference, RENEXPO, Warsaw, 18.10.2012