River water is directed onto paddle wheels, which are set in motion and drive generators, which in turn convert the mechanical energy into electricity. The principle of a hydropower plant is simple. With this technology, which provides "clean energy" 24 hours a day, seven days a week, it’s a challenge the devil is often in the details.
Alexander matthes (49), hartmut kolb (58), thomas weberpals (52) and stefan weigel (46) can tell you a thing or two about it. All four are operators of "small hydropower plants". Whereby the designation "small is an understatement, because with the plants in kulmbach, unterzettlitz, kauerndorf, neuenreuth and kleinziegenfeld, several villages can be supplied with power at the same time.
Compared to wind farms and solar parks, mills offer several advantages: for example, electricity from hydropower is produced continuously and largely independent of the weather, making it an important factor in base load supply. He also scores points in terms of sustainability: while the disposal of wind turbines and photovoltaic modules after their useful life has not yet been fully clarified, as questionable materials are used, the components of a hydroelectric power plant can usually be recycled without any problems. Further plus points are the high efficiency (around 90 percent) and the longevity of hydropower plants.
With all these advantages, the question arises as to why the use of hydropower is often treated stepmotherly in the context of the desired energy turnaround? Why not invest more in hydropower instead of disfiguring the landscape with wind turbines and open-air PV plants??
One reason is certainly that this energy policy issue has been strongly influenced in the past by the lobbyists of the large energy suppliers. "Centralized instead of decentralized" was the motto in the past. In addition, there are legal obstacles. Hartmut kolb: "to operate a hydropower plant, you have to own a water usage right." And this is usually inherited with a muhle or other property. A reallocation is subject to very high requirements.
Moreover, the operation and maintenance of a hydroelectric power plant is not everyone’s cup of tea. As a private citizen, it already requires special skills. This includes a pronounced enthusiasm for technology, rough craftsmanship and commercial thinking. "You have to be able to do and repair a lot yourself. If you need a company for every little thing, it doesn’t pay off", weib alexander matthes, who, like his three colleagues, is a tufter and addresses another problem: "every plant is different, has its special features, about which mostly only the operator knows."
It is true that there are some specialized companies in germany. But their services are often simply too expensive, which is why mathes& co. Relying on on-site lots, the experience with this is very good.
In "standby mode
The "standby mode is another common feature of the hydropower workers, who exchange ideas regularly and by no means see each other as competitors. "Which is why? No one is taking anything from anyone else", according to matthes.
Compared to wind power and PV plants, the time required for regular maintenance is much longer. In order for the water-powered plants to produce electricity without problems, the rakes in the intake must be cleaned regularly. It can happen that floating debris has to be fished out on a daily basis. "It’s nothing unusual to go into the cold water with the motorsage to cut up and remove a wedged tree", tells hartmut kolb.
Shortly before christmas, stefan weigel was startled by an error message while on ski vacation. A rough stump of deadwood had broken through two so-called stumpage protectors. In particular, the removal of the 16-meter-long tree proved to be difficult.
Other problems occur during the months of low precipitation. When the water level drops, less electricity is produced. In the past two summers, electricity production fell by up to 40 percent. Hartmut kolb even had to shut down operations for a few weeks in 2018 so that the plant would not be damaged.
Although hydroelectric power generation is considered environmentally friendly, there are critics here as well. Animal rights activists point out the dangers to fish, which is why operators are required by law to take appropriate precautions, which are also regularly and unannounced inspected by the authorities. The maintenance of a small hydropower plant is also associated with a high financial risk for the operator. Alexander matthes invested a six-figure sum in the overall renovation of the limmersmuhle in 2012.
A kind of old-age provision
The expenses for renovation and maintenance measures are offset by the income from the sale of electricity. However, it takes many years to reach the break-even point, which is why many operators also view their investment as a retirement plan.
However, it is difficult to calculate the hours worked by the operators and, above all, the risk of higher levels of violence. Stefan weigel and his colleagues are assuming that "the general conditions will worsen and the outflow will increase". In the future, there will be a lot more heart and soul at the hydropower plant …