THE WATER cycle is endless and hydropower is the second most highly utilised source of energy in the world. Slovakia is a country criss-crossed by rivers that can be harnessed to produce electricity. And while large rivers have been extensively used for this purpose, other, so-called small hydropower plants can still be built on smaller rivers.
“In general, we can say that utilisation of the hydro energy potential of our rivers is one of the most environmentally acceptable ways of generating electricity,” Environment Ministry spokesman Maroš Stano told The Slovak Spectator.
Greenpeace Slovensko notes that small hydroelectric plants are a renewable resource with stable output, compared to, for example sun or wind. Their main disadvantage can be permanent and large-scale interference with the environment.
“Small hydropower plants represent a decentralised source of electricity production,” Miroslava Ábelová from Greenpeace Slovensko told The Slovak Spectator.
Global solutions and local problems
In Slovakia hydro-energy dates back to the 14th century, when water mills were built to run the machinery in mines. In the 19th century, water plants started to be used to generate electricity. Nowadays, water energy makes up almost 90 percent of all energy generated from renewable sources, which provides 16.6 percent of the country’s energy consumption.
The Regulatory Office for Network Industries (ÚRSO) registers 21 big power plants and 212 small ones with less than 10 MW of installed capacity. The dominant power producer, Slovenské Elektrárne, operates all the big plants except for the Gabčíkovo hydropower plant which is operated by the state Vodohospodárska Výstavba. The majority of the small plants are constructed by private investors.
In 2011, Prime Minister Iveta Radičová’s cabinet adopted a concept for increased hydroelectric capacity by 2030, in which it identified 368 locations for small hydropower stations. The plan called for increasing the capacity of electricity generated by small hydropower stations from 250 GWh/year in 2005 to 850 GWh/year in 2030. The total hydro-energy potential of rivers in Slovakia is 13,682 GWh/year, according to the 2011 concept paper.
That large number of potential small hydropower stations raised concerns and opposition from nature protectionists as well as citizens in affected municipalities, but the Environment Ministry explained that 368 is not the number of small hydropower stations that would be actually built. Moreover, the current ministry has halted allocation of profiles for construction of small hydropower stations and none have been cleared for construction during its term, Stano said.
Greenpeace considers the proposal as too ambitious.
“This topic requires more public discussion, mainly when during the creation of this concept the opinions of the public were not accepted,” Ábelová said. “Moreover, it should be put in harmony with the directive on the protection of waters.”
According to Marcela Morvová from the Department of Astronomy, Physics and Meteorology of Comenius University, Slovak rivers can sustain a maximum of 118 small hydropower stations without causing permanent damage to the environment.
“If I took into consideration the annual river flow, 118 small water plants could generate about 150 Mwh,” she said.
Morvová warns that to avoid negative effects, small hydropower plants should not be built as a small copy of a large hydropower station.
“A small hydropower should not totally block the flow of the river,” she said, pointing to an existing plan for a small hydropower station to be built on the Small Danube river.
She gives a positive example of a power station built as a bridge from which small turbines are hanging. Such systems are used in several fjords in Norway. Or it is possible to build something like piers from both banks of the river, with one to three small turbines. Such a scheme is used in Interlaken inSwitzerland.
“Both above-mentioned systems completely eliminate all the negatives of the so-called embedding in concrete situation because in either case they do not affect biodiversity, migration of water species, pH and the content of oxygen in water, self-cleaning ability of water, water tourism and navigability of the river,” said Morvová.
Ábelová added that each small hydropower plant must be assessed from the point of view of its impact on the environment.
“In principle we support construction and development of small hydropower plants, but under the conditions of strict protection of nature and water sources,” said Ábelová, adding that a power plant can be an obstacle for migrating fish and damage the water bed, which affects the whole ecosystem. “If incontrovertible interference with protected areas and serious damage of the environment can occur, then we are unambiguously against such projects.”
Permitting the construction of small hydropower plants follows construction laws, according to which the pertinent construction office, the municipality, issues a development permit, the Environment Ministry explained. This is followed by the building permit process at a special construction office.
Although the Environment Ministry is not responsible for the permit process, it is ready to take action against small hydropower plants, either in the preparation, construction or operation phases. This has happened recently in the cases of the small hydropower plants Čirč and Eliášovce.
In Čirč, the owners of a small hydropower station built an illegal dam on the Poprad River. Offices supervising the matter have discovered a violation of water and construction laws and ordered the removal of the dam.
In September 2015, people from Eliášovce signed a petition against the construction of a small power plant on the Malý Dunaj (Small Danube) river that reportedly violates the European regulation on waterways.
The investor responsible for the particular project, Prvá produkčná, rejected all the allegations. Yet about 50 groups of opponents, including city mayors, fishermen and agricultural cooperatives joined the opponents and managed to postpone construction.
“We are convinced that the negative influences of the construction and operation of the small hydropower station highly exceed its declared benefit,” reads the petition.
Universal alternative source does not exist
Carbon dioxide gases in the atmosphere reached all time highs in 2014, the World Meteorological Organisation reported in a press release on November 9, which puts the planet at risk. It can result in irreversible climate change. With the global conference on climate change set to open in Paris, alternative energy sources again top the agenda.
Ábelová of Greenpeace Slovensko suggested more effective utilisation of Slovakia’s potential in solar and wind energy, as well as geothermal energy and biomass. However, combustion of biomass from organic material increases the level of CO2 emissions. This excludes biomass from the list of large-scale renewable energy sources as there is always some residual CO2 emitted into the atmosphere.
Morvová believes that it is neither sensible nor possible to put some types of renewable energy sources (RES) at an advantage or suppress their usage.
“RES have the advantage that they are relatively well diversified and especially that they mutually supplement each other,” said Morvová, stressing that RES methods do not include only production of electricity but also heat, transport and introduction of all available possibilities for energy storage.
“Advancing to a higher share of RES in the energy portfolio is a long-distance run, not a sprint,” said Morvová, adding that in Slovakia a closely connected area is waste management. In Slovakia most waste ends up in landfills, while it could otherwise be used to generate electricity and heat.
Slovakia has a commitment towards the EU to increase the share of renewable sources to 24 percent by 2020, which will result in lower usage of coal or other fossil fuels, recalled Stano.
“The hydro-energy concept is being updated at the moment and the result will be stricter requirements in terms of protection of the environment, including water,” said Stano. “Construction of power plants will have to include fish ladders, various bio-corridors and measures to eliminate hydrologic changes in the water flow.”