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What is wind energy? How is it generated? How do wind turbines work? What is the difference between onshore and offshore wind energy? What are the advantages and disadvantages of wind energy? How can wind energy be stored? These and many more questions are answered in this article. So that you can make an informed decision as to whether you want to participate in the wind energy business as a wind energy producer or as an investor.
The target is quantified. With a draft law to increase and accelerate the expansion of onshore wind turbines (WEA) (so-called Wind-an-Land-Gesetz), which was approved by the federal cabinet in mid-June, Germany wants to accelerate the expansion of onshore wind energy.
This is because the expansion of wind energy is crucial both to strengthen independence from fossil imports and to achieve the climate targets. The draft of the EEG 2023 therefore significantly raises the expansion paths for onshore wind energy. In order to ensure that sufficient areas are available for onshore wind energy, about 2 per cent of the federal territory is necessary in the medium to long term. This goal was anchored in the coalition agreement. Currently, 0.8 per cent of the federal state's area is designated for onshore wind energy, of which only 0.5 per cent is actually available.
The Federal Environment Agency explains this discrepancy on its website as follows: If one takes into account the restrictions resulting from settlement distances, such as the 10-H regulation in Bavaria, other height restrictions, the prohibition of wind energy in forests, such as in the Thuringian Forest Act, and the widespread requirement that the rotor radius must lie within the territorial boundary, the available area is reduced to a share of 0.52 per cent of the state's land area.
The law to increase and accelerate the expansion of onshore wind energy plants obliges the federal states to make a share of 1.8 to 2.2 percent of their land area available for the expansion of wind energy by the end of 2032, according to the associated press release. Accordingly, the city states would have to designate 0.5 per cent of their state areas. The distribution takes into account the different conditions of the federal states. The law provides for an interim target of 1.4 per cent for the end of 2026.
The bill therefore also contains a new conception of the Länder opening clause for minimum distance regulations under Land law. "We are dividing this up fairly regionally, taking into account wind conditions, nature and species conservation and spatial orders," Vice-Chancellor and Federal Minister of Economics Dr Robert Habeck told the press. "It remains up to the Länder to decide how they meet their land targets. However, we rule out any prevention planning," Habeck emphasised.
Wind is primarily the result of the sun's activities. When the sun's rays hit the earth, some of them are absorbed. Heat is generated in the process. As the earth's surface warms, so does the air above it. Warm air expands, which causes it to become thinner and lighter. This causes the warm air masses to rise.
This creates low pressure near the ground. In places where it is cold, on the other hand, the air sinks and high pressure forms on the ground. To equalise the pressure between neighbouring air masses with different temperatures, colder air flows to where the warm air rises.
The following applies: The greater the temperature difference, the faster the flow. This means that a stronger wind blows. Wind energy is therefore energy that air masses possess due to their movement.
Wind energy can be harnessed with the help of wind turbines, also called wind power plants (WKA) or wind turbines. This is because the wind power that hits the rotor blades of the turbines sets them in motion so that the associated rotor turns. A generator finally produces usable electrical current (electrical energy = electricity) from all the kinetic energy (mechanical rotational energy).
The following applies: The higher the wind turbine is and the stronger the wind blows, the higher the electricity yield of the system.
Wind energy is renewable energy; no CO2 is emitted during its production. Like solar energy, wind is free energy that is available almost everywhere around the globe. Like the sun, it is considered an inexhaustible source of energy.
The English expression "on shore" means: "on land". And the expression "off shore" means: "off the coast". Accordingly, a wind turbine located on land is an onshore turbine, while one located off the coast in the sea is an offshore turbine.
The following applies: On average, more electricity can be generated per wind turbine at sea, but the construction of an offshore turbine is also significantly more expensive than that of an onshore turbine.
In this country, it is regulated by law where a wind turbine may be built. The basis for this under building law is the Building Code (BauGB). In principle, it stipulates that wind turbines may be erected in so-called outdoor areas, i.e. outside built-up areas and residential areas.
In the outer area, construction is only allowed under very strict legal conditions. According to § 35 paragraph (1), wind turbines enjoy a so-called privileged status - they are therefore considered "privileged building projects". However, this is only the case if, according to § 35 paragraph (3), no "public concerns" such as "land use plans, landscape plans or harmful environmental effects" stand in the way and sufficient development is ensured. To ensure that there are no obstacles to "public concerns", the German legislator has enacted further laws that define these in more detail. If all other requirements for a permit are met, it must be granted.
In order to regulate where exactly a wind turbine may be built, the municipality concerned can draw up a so-called land use plan that designates areas for it. Very specific criteria must be met for this, including:
- Minimum distances from residential areas: Different distances are set here depending on the federal state, for example 1,000 metres (Brandenburg, Saxony). In Bavaria, the 10-H distance rule applies, where 10 H stands for ten times the height of the turbine. In the course of the new laws on the expansion of German onshore wind energy described at the beginning, the federal government explains that the federal states would still be allowed to decide on minimum distances, but in future they would have to ensure that they achieve their area targets from the Wind Energy Area Requirements Act and thus make their contribution to the expansion of wind energy. To this end, the Länder opening clause in the Building Code would be redesigned to allow blanket statutory minimum distance regulations by the Länder.
Excursus: The federal government answered the question of what the new legal regulations actually mean for existing distance regulations under Land law, such as the Bavarian 10-H rule or the 1,000-metre distance regulations in Brandenburg and Saxony, as follows:
Existing distance regulations of the Länder would have to be adapted. A transitional period until 31 May 2023 applies for this, the reason being that in future, distance rules may no longer extend to wind energy areas according to the Wind Area Requirements Act (WindBG). If the existing distance regulations were not adapted in time, they would no longer be valid. Accordingly, the so-called Länder opening clause would continue to exist. This means that the federal states could in principle continue to enact minimum distance regulations on the basis of the Länder opening clause.
However, the Länder opening clause would be linked to the new WindBG. If a federal state violates its obligations under the WindBG, i.e. fails to achieve the 2026 and 2032 area targets (see above) or cannot demonstrate sufficient implementation steps on the way to achieving the targets as early as 2024, the distance regulations under federal state law would become inapplicable, i.e. they would then automatically cease to apply.
In addition, minimum distance regulations should not lead to land restrictions in the future, which would run counter to the implementation of the 2 percent land area target.
- Nature conservation and species protection: Wind turbines may only be erected in nature conservation areas or landscape protection areas in exceptional cases.
- Bird protection: Minimum distances must be maintained from existing nests of bird species sensitive to wind power. And sites where the capercaillie lives permanently must not be built on.
- Radar installations and air safety: Precautionary distances must be maintained around airfields and radar installations.
- Water protection: Water protection areas or protected spring areas must not be built on with wind turbines. Air safety and road traffic laws must be observed.
- Landscape protection: When erecting wind turbines, impairments to the landscape can (but do not have to) be taken into account.
In the course of presenting the new laws on accelerated wind energy expansion, the federal government told the press that it would be legally ensured in the Federal Nature Conservation Act (BNatSchG) that in future landscape protection areas could also be included in the search for areas for wind energy expansion. At the same time, protection zones for endangered species would be defined and high ecological standards guaranteed.
In order to simplify and accelerate approval procedures for onshore wind turbines, uniform federal standards would be set for the assessment of species protection. A list of breeding bird species at risk of collision will be defined for the significance test. In addition, there would be staggered, species-specific and breeding site-related distance requirements with a taboo area and test areas.
To facilitate the granting of exceptions, it is first clarified that the operation of wind turbines is in the overriding public interest and serves public safety. According to the federal government, the alternatives assessment and the species protection exception assessment will be simplified. For the repowering of onshore wind turbines, species protection-related requirements would be incorporated into the Federal Nature Conservation Act and further specified there.
In addition, the Federal Agency for Nature Conservation will be mandated to set up national species assistance programmes to support species affected by the expansion of renewable energies.
Accordingly, plant operators are also to contribute to the financing of these programmes.
Do you need a permit or not? - In the case of wind turbines, this depends on their height. According to the Federal Immission Control Act, the actual approval procedure applies to wind turbines over 50 metres high.
It is important to know that a permit under this law has a so-called concentration effect: it therefore includes all permits that would be due separately, for example the building permit.
The actual approval procedure for the wind turbine starts with a written application. The subsequent process depends on whether
- a simplified
- or a formal
approval procedure is used. The following applies: If more than 19 wind turbines are planned, a formal procedure is required. The law also stipulates when an environmental impact assessment (EIA) is required and when it is not.
Excursus: Simple and formal procedure - what is the difference?
The main difference between the two approval procedures is that public participation is not required for the simplified procedure. The formal procedure is different: There it is mandatory. This means that the building project in question must be made public - in the form that the application and the associated documents must be put on public display for one month.
During this period plus two additional weeks, the public can address any objections to the authority responsible for approving the wind turbine(s). The authority then decides whether or not to hold a hearing at which those concerned can explain their objections in more detail. After this hearing and the participation of other authorities concerned, a decision is then taken on the application. The corresponding decision is to be published again.
A so-called environmental impact assessment (EIA) must always be carried out if a wind farm consisting of at least 20 wind turbines is to be erected. In terms of the EIA Act, a wind farm is characterised by the fact that the turbines are
- are more than 50 m high
- their impact areas overlap
- and that they are functionally interrelated.
However, this does not necessarily mean that the turbines have the same operator.
An EIA is also required if
- for 6 to 19 installations, a general
- or, for 3 to 5 installations, a site-specific preliminary
Site-specific preliminary assessment has shown that the construction project could have significant adverse environmental impacts. This case is rather rare.
Important: If an EIA is announced, there is always an obligation for public participation.
In the course of the environmental impact assessment, the so-called developer must prepare a report in which he describes his project in concrete terms and describes the likely significant environmental impacts of his project.
On the basis of this report, the competent authority is to be able to examine the environmental impacts.
For its part, the permitting authority must obtain opinions from all other authorities concerned and also involve the public in the process.
The expansion of renewable energies is accompanied by the expansion of storage technology to store surplus renewable energies for later use. Various storage technologies, including battery storage, pumped storage power plants and compressed air storage, are already in use. Research laboratories around the world are working on others.
So far, there is no storage solution for wind energy that pays off on a large scale. That is why wind millers, i.e. the operators of wind turbines, (still) switch off the wind turbines or turn them into the wind so that they stand still in order to avoid grid overload. Sometimes the electricity is also diverted to other grids at so-called negative prices, whereby the costs are not borne by the turbine operator, but are imposed on the consumer.
According to the Federal Environment Agency, wind turbines would pay for themselves in terms of energy after approximately three to seven months. Payback means that after the payback period, the turbine generates as much energy as has to be spent on its production, operation and disposal.
The UBA explicitly points out that the three to seven month payback period mentioned is very short - compared to other renewable energy generation technologies. And that conventional energy generation plants would never pay for themselves in terms of energy. This is because more energy in the form of fossil fuels would always have to be used to operate them than the amount of useful energy obtained.
In addition, the use of wind energy scores points because it has the most economic expansion potential of all renewable energies in the short to medium term.
Although the cost of a wind turbine varies, depending on the size of the turbine (capacity) and the location, the average cost of a turbine can be estimated at between 1 and 4 million euros.
It is important to know that most of the costs are for the construction and installation of the turbine, with the rotors and the tower being the most expensive.
The remaining costs are usually for the construction work, especially on the foundation, as well as permits. After installation, the wind turbine has comparatively low operating costs. Maintenance costs are usually low. Only the electricity needed to operate the turbines is still a larger item on the turbine's operating cost bill.
This is also the reason why wind turbines are considered a very cost-effective way to generate renewable energy.