Small hydropower plants
If a stream or river flows through your property, or you have access to a spring, a small hydropower plant can be an economically attractive, long-term energy source. Unlike photovoltaics, hydropower generates electricity continuously, regardless of the time of day and weather conditions. Conversio Energie plans and builds small hydropower plants for private landowners, farms and municipalities in Austria.
When is a small hydropower plant worthwhile?
Not every watercourse is suitable for generating electricity. The economic viability of a small hydropower plant depends on two key factors: the available water volume (flow rate in litres per second) and the usable vertical drop, or head. The greater the flow and head, the more electricity can be generated.
Suitable locations
Streams and rivers with sufficient year-round flow, springs with a constant discharge and usable head, and drinking water or irrigation pipes with an unused pressure drop can all potentially serve as locations for small hydropower plants.
Who is this solution suitable for?
Farms with their own watercourse benefit particularly because generating their own electricity permanently reduces operating costs. Municipalities with suitable streams and private landowners in mountainous areas are also typical candidates.
How does a small hydropower plant work?
Water is directed through an intake structure to a turbine, which is driven by the water's kinetic energy. The turbine transfers its rotation to a generator, which produces electricity. An inverter conditions the electricity so that it can be fed into your own network or the public electricity grid.
Turbine types
The right turbine depends on the head and flow rate. Pelton turbines are used for high heads and low flow rates, Francis turbines for medium heads and medium flow rates, and Kaplan turbines for low heads and high flow rates.
Water wheels are a simpler alternative for very small installations with minimal flow.
A preliminary hydrological assessment determines which turbine is suitable for your site.
Service life and maintenance
Properly designed and built small hydropower plants can operate for more than 50 years. Compared with other renewable energy technologies, they require very little maintenance, as there are no moving parts outside the turbine and no wear caused by UV radiation or temperature fluctuations.
Planning and permits
Building a small hydropower plant in Austria requires a water permit under the Water Rights Act (WRG). The approval process includes a hydrological site analysis, an ecological assessment of the watercourse, an assessment of residual flow and, for larger installations, an environmental impact assessment where required.
This process is complex and time-consuming. Depending on the federal state, authority and installation, it can take several months to more than a year. Submitting complete documentation early is essential to avoid delays.
Small hydropower subsidies in Austria
Small hydropower plants can receive investment funding and/or a market premium for electricity fed into the grid under the Renewable Energy Expansion Act (EAG). The market premium guarantees a fixed supplement to the market price for a specified period and significantly improves the plant's economic viability.
Some federal states also offer their own small hydropower funding programmes, particularly regions with a long hydropower tradition such as Tyrol, Styria and Carinthia. Our advisory team will explain the programmes currently available for your location.
Frequently asked questions
How much electricity does a small hydropower plant generate?
This depends directly on the flow rate and head of your watercourse. As a rough guide, a system with a flow of 50 litres per second and a head of 5 metres generates around 2 kW of power, producing approximately 15,000 to 17,000 kWh of electricity per year. A reliable yield forecast is only possible after hydrological measurements at the site.
How much does a small hydropower plant cost?
Investment costs depend on the site and vary considerably. Simple micro installations with water wheels start at a few thousand euros. Larger turbine installations with hydraulic structures and a grid connection can cost several hundred thousand euros. A reliable cost estimate is only possible after site analysis and concept development.
Do I need my neighbour's consent?
This depends on the location of the watercourse. Where water flows across several properties, coordination with neighbours or the municipality may be required. The water permit procedure formally clarifies these issues.
How long does the approval process take?
Depending on the federal state, installation size and completeness of the submitted documentation, the process can take between six months and more than two years. Early contact with the relevant water authority and careful preparation of the application documents are essential.
Can I combine a small hydropower plant with a PV system?
Yes, and it often makes sense. Hydropower reliably generates electricity in winter and during rainfall, while photovoltaics produces strongly in summer and sunshine. Combining the two technologies evens out annual electricity production and significantly increases self-sufficiency. Conversio Energie plans both systems and can take their integration into account from the outset.