Before buying a private wind turbine for your own home, you have to know the most important factors for success. A wind turbine for the home is subject to its own rules, not comparable to solar systems.
Especially in the market segment of home wind turbines, there are not only good manufacturers and specialist companies but also questionable providers who do not give consumers honest advice.
A small wind turbine can be the perfect complement to photovoltaics and electricity storage, provided you know the basic conditions.
Here are a few honest tips from neutral experts…
Performance and size of private wind turbines
Most private wind turbines have a nominal output of up to around 5 kilowatts. It is not possible to give a general statement on annual electricity generation, as is the case with photovoltaic systems (solar power).
It’s easy with photovoltaics: you can expect an average of 1,000 kWh of electricity per year per kilowatt of output. In the case of a small wind turbine, the size of the rotor and the wind available at the location determine the earning power.
Regarding annual electricity production: Depending on the wind strength at the installation site of the small wind turbine, a system with a 5 kW output can generate between 2,500 and 10,000 kWh of electricity per year. A huge difference. A very high yield is possible, for example, in an open location near the coast. But be careful: In the slipstream, a wind turbine will generate almost no electricity.
The height of a small wind turbine is defined by building law in the form of the highest blade tip of the turbine. Private wind turbines rarely exceed 65 feet of overall height. In many states, wind turbines can be erected up to 32 feet tall without a permit. The higher the pole, the stronger the wind on the rotor. Very low wind turbines therefore often do not have enough wind.
You shouldn’t be looking for returns
Anyone who pursues profitability and saving electricity costs as their main motive will not get very far with a wind turbine for their private home. The first step should always be the installation of a solar power system, which can be operated economically in most cases.
When are small wind turbines worthwhile financially?
a) If your own wind power is cheaper than the electricity price of the energy supplier and
b) if most of your own electricity is consumed by yourself, i.e. it is not fed into the grid.
The costs of the electricity produced by the wind turbine are referred to as electricity production costs. Roughly speaking, the electricity production costs of private wind turbines would have to be less than 20 cents per kWh to be lower than the price for household electricity. This can only be achieved with a private wind turbine with an output of up to five kW at very windy locations. Many private plots of land in residential areas do not have such a location.
The motives for purchasing a private wind turbine should be environmental and climate protection, fun with technology and/or the desire for self-sufficiency.
Efficiency and returns are possible above all for commercial enterprises with higher power consumption and small wind turbines from 10 kW output.
Installation on the roof?
The small wind turbine should be installed on a ground mast near the building. Installations on the roofs of wind turbines for single-family homes are usually not crowned with success. Mainly due to insufficient wind conditions. A roof installation could work, for example, if one side of a gabled roof has a free flow from the prevailing wind direction and the pole is of sufficient height. Many private homes do not meet this requirement.
If you have serious use of green electricity technology and significant electricity production in mind, you will choose a pole installed on the ground. Does a provider mainly recommend roof systems? Then look around for another provider.
Self-sufficiency = photovoltaics + small wind power + electricity storage
A big advantage of a small wind turbine: it produces a lot of electricity, especially in autumn and winter. A perfect addition to the solar power system. Of course, the nocturnal power generation of a wind turbine is also a plus point.
A power storage unit can be powered by photovoltaic and small wind turbines, provided it has been planned correctly. AC-coupled power storage should be used. The electricity from the wind turbine is fed into the house network by its own inverter (110 – 230 volts) and thus reaches the battery.
With the combination of solar + wind power + electricity storage, you can achieve a very high level of self-sufficiency with environmentally friendly electricity over the year. An electric car, which can then be charged with solar and wind power, is ideal in this context.
Even if a wind turbine is primarily used to generate electricity, it can also be used to generate heat. After all, the windy season is also the heating period. Excess electricity from the wind turbine is fed into a heating element and produces hot water.
If you have a heat pump, i.e. a heating system that requires electricity as an auxiliary energy, then the wind power is also used to operate the heat pump.
Conclusion: Photovoltaics and (if desired) electricity storage should be installed first. The mini wind turbine fills the solar power gap in winter.
A windy location is particularly important!
It cannot be repeated often enough: the #1 success factor for wind turbines is the wind speed at rotor height (annual average).
Even if profitability is not the focus when purchasing a private wind turbine, you will not have fun with the wind turbine if hardly any electricity is produced due to insufficient wind potential on the property.
If the electricity production is low, the ecological balance of the wind turbine for the home will not be rosy. A wind turbine is only climate-friendly if it generates more electricity during the entire operating time than was needed to manufacture the system.
Small wind turbines are much more location-critical than solar systems: a small wind turbine cannot be operated on every property. There will be no success with the private wind turbine if several thousand dollars are invested and only a few kilowatt-hours of electricity are produced per year.
Strong wind locations can occur on the western outskirts of settlements, in individual locations as well as on slopes and at high altitudes.