Against the background of the Kyoto targets and the EU Directive on the promotion of renewable energies (2001/77/EC), there are still initiatives being created, which, after the end of the construction boom at the beginning of the 1990s, still tap existing potentials.

Austria and particularly the federal capital have lately massively supported Slovakian small hydropower advocates. The most important reason is the intensified anti-atomic lobbying against the extension of the atomic power station Mochovce, which is only 150 km away from Vienna.

Vienna offers as an alternative an increased transfer of know-how with regard to alternative energy sources. The latest example for these efforts was the symposium “Small Hydropower Plants”. The top-class expert meeting, presented by the Vienna Environment Attorney Andrea Schnattinger and Peter Ben Šus Ška (Europahaus Bratislava), took place on 14 September in Bratislava.

In her opening statement, Vienna’s Executive Councillor of the Environment Ulli Sima emphasised that not only numerous Austrian enterprises had vast experience in the field of small hydropower, but also the federal capital itself.

Sima referred in this context to the 13 drinking water power stations, which have been operated by Vienna’s Waterworks (MD 31) and Wienstrom for decades along the 1st and 2nd High Spring Water Pipeline. Friedrich Rödler (MD 31) and Thomas Feige (Siemens Industrial Solutions and Services) presented in this context the recently revitalised Drinking Water Power Station Mauer, designed as a PPP model of the Municipality and Siemens.

Alfred Schmitt of VA TECH Hydro GesmbH & Co, Richard Kellner (VERBUND-Austrian Hydro Power AG), and Werner Panhauser of the Lower Austrian turbine specialist Kössler GesmbH offered an overview of the latest technological developments.

Alfred Schmitt presented the turbine/generator system “Compact Hydro” and the “ECOBulb” turbine. Richard Kellner’s presentation dealt with the successful application of a further VA TECH-product, the “Hydromatrix”, in the Small Hydropower Plant Nußdorf.

Werner Panhauser’s presentation concerning the projects “Gönes Hes” (Western Anatolia), “Dorfmühle” (near Kematen/Yybbs) and “Una – Kostela” (near Bihac, BiH) proved that the small hydropower “renaissance” presently observed in many places, did not only concern new constructions, but even more so, the revitalisation of old plants.

What conditions, however, prevail in Slovakia in the face of this concentrated know-how? The information of the West on local hydropower mainly bases on a study carried out in the framework of the Thematic Network on Small Hydropower under the auspices of the European Small Hydropower Association/ESHA. ESHA President Berhard Pelikan: “The statistical data on small hydropower (output over 10 MW) in Slovakia show great differences depending on sources.

Even national institutions only have little reliable data on the number of small hydropower stations. The main reason for this is the fact that output limits for small hydropower stations are differently defined.” However, the Slovakian and Austrian experts largely agree that about 180 plants with a total output of approx. 67 MW were in operation by the end of 2002 and generated about 250 GWh/a eco-electricity.

Further 35 are presently being planned. When in operation, this would be an additional energy of 55 MW, or 240 GWh/a. Remarkable because the fact is atypical that as much as half of these plants have been built only during the past twenty years (see chart).

As expected due to the topography of the country, low-pressure power stations prevail in Slovakia (about 50 %) with a head of maximally five metres. Medium-pressure power stations (head 5–15 metres) account for one third, and high-pressure power stations with heads of over 15 m are rather rare (15 %).

Data differ again on the theoretical small-hydropower total potential, but there is agreement on the technologically possible potential, which is 1,200 GWh/a. The economically developable potential is estimated to amount to 1,000 GWh/a (with an output of 267 MW).

Thus, only 25 % of the potential are presently exploited in Slovakia or – according to Igor Ilias Š of the Energy Centre Bratislava – only about 5 % of the renewable energy sources are covered by small hydropower. Ilias Š: “Renewable energy sources in our country presently supply about 6.6 TWh/a, which corresponds at least to about 20 percent of energy consumption. Meanwhile, the Government has lowered the development target of 31 percent set by the EU until 2010 to 19 percent.”

Nonetheless, according to Pelikan, efficient supporting instruments for the “renewables” would be required (also throughout the EU). The expert quotes in this connection “reasonably high feeding tariffs for eco-electricity; 4.5 euro cent are the lowest limit!”, and an urgently required simplification (but not easing!) of approval procedures.

Pelikan also subtly criticises the EU Water Framework Directive. He claims its pragmatic translation in national legislation. In addition, it would be necessary to provide for small hydropower, too, an investment security for about 15 years and a reliable legal basis.

Pelikan: “Slovakia-specific obstacles for small hydropower development come from fishery and land use. Thus, the construction of small hydropower stations in national parks and landscape preservation areas is forbidden. An environmental impact assessment is required for all plants above 20 kW. The losses from minimum-discharge amounts range between 5 and 10 percent.”

In Slovakia, there exists a master plan for the further development of small hydropower. On the other hand, there is no intention to create more specifying local or regional development plans. Approvals for water extraction for power generation are issued for a maximum of 30 years (against payment of a water-use fee).

Authorisations for power production are not limited in time. According to Kvetoslava S Šoltésová, CEO of the Slovakian Energy Agency, national funds would also be available for the promotion of small hydropower in addition to EU funds for structure programmes, but they are split between the different ministries.

“About 10 million korun of the provided funds had to be returned lately, because they were not claimed,” says S Šoltésová, thereby sending also a signal to foreign investors.
(Source: aqua press Int. 3/2005, Mag. Christof Hahn)