Careful planning is crucial to maximizing the efficiency and economic viability of a small wind turbine. It helps ensure that the small wind turbine operates optimally and meets the specific requirements of the site. Planning requires consideration of various aspects, including site factors, power demand, regulatory requirements, and economic evaluations. The following sections describe the necessary steps for planning a small wind turbine:
1. Location analysis
2. Power consumption
3. Dimensioning and selection of the small wind turbine
4. Revenue forecast
5. Economic efficiency and profitability of a small wind turbine
6. Legal framework
Steps in planning a small wind turbine
1. Location analysis
Location, location, location. This applies not only to real estate, but especially to the location of a small wind turbine. Factors such as average wind speed and the unobstructed wind flow onto the turbine are considered in the site assessment.
Information from wind atlases, measurement data from nearby weather stations, or online tools can be used to determine wind speed. However, these only provide an indication of the wind potential. Since small wind turbines are predominantly installed at heights below 30 m, they are exposed to wind conditions in the air layers close to the ground. In this range, the wind can be repeatedly deflected and swirled by obstacles such as buildings, trees, or hedges, and even locations close to one another can have very different annual wind speeds. Therefore, ideally, wind measurements should be carried out over a period of at least 3, and preferably 12, months. Appropriate measuring systems can be rented or purchased from specialist retailers. According to experts, a good location should have an average annual wind speed of approximately 4 m/s.
A clear flow of wind from the prevailing wind direction onto the small wind turbine is also crucial. As a rule of thumb: If an obstacle in the prevailing wind direction is of a certain height, the distance between the small wind turbine and this obstacle should be 20 times the height of the obstacle. For example, if a 10 m tall tree is in the prevailing wind direction, the small wind turbine should be installed approximately 200 m away from this tree.
2. Power consumption
Determining the electricity demand serves as a guide for dimensioning the small wind turbine and can be determined using existing electricity bills. If these are not available, guidelines can be used. For example, a family of four in a single-family home has an average annual electricity demand of approximately 5,000 kilowatt hours. When planning electricity demand, long-term changes such as the purchase of an electric car or a heat pump should also be considered.
3. Dimensioning and selection of the small wind turbine
The size of the small wind turbine depends on the planned power consumption, the wind conditions at the location and whether additional components such as photovoltaics or storage systems are integrated.
The goal when designing a small wind turbine is to utilize the generated electricity as much as possible. The value of the energy costs saved by a small wind turbine is usually significantly higher than the compensation for feeding it into the grid.
When selecting a suitable small wind turbine, it is important to ensure that it is certified according to the IEC 61400-2 standard. While this is not mandatory in most countries, including Germany, it is a sign of quality. There are also independent recommendations for small wind turbine manufacturers. Furthermore, it is important to check whether independent test results for noise emissions, power curves, and yield are available. For grid connection, grid operators in many places require a type certificate confirming the small wind turbine's grid disturbances. A manufacturer's declaration is only valid for a limited period of two years and must subsequently be verified with a certified certificate.
4. Revenue forecast
From the wind measurement data and the power curve of the selected small wind turbine, a forecast of the expected annual electricity yield can be made.
5. Economic efficiency and profitability of a small wind turbine
The profitability analysis considers the financing of the small wind turbine and the long-term cost savings through self-generated electricity generation or grid feed-in. Based on this, statements can be made about the long-term profitability of the small wind turbine and a financially viable financing strategy can be developed.
The investment costs for a small wind turbine can vary depending on the size, output, and technical components. Traditional equity financing and debt financing are the main options for financing a small wind turbine. Furthermore, potential funding programs and tax benefits should also be considered in your investment planning.
6. Legal framework for the construction of a small wind turbine - From building permits to reporting requirements
Before purchasing and constructing a small wind turbine, the applicable building permit requirements, legal provisions, regulations and reporting obligations must be checked. Compliance with these requirements ensures the smooth operation of the small wind turbine and protects against unexpected costs or legal consequences.
Due to the federal structure of building law in Germany, the building permit process for small wind turbines depends on the location. The key criterion is the total height of the small wind turbine, measured from the ground to the highest point of the rotor blade tip.
In some federal states, the construction of small wind turbines with a total height of 10 m does not require a permit; in almost all federal states, a building permit is required for small wind turbines with a total height of more than 10 m. Before erecting a small wind turbine, it is advisable to contact the local building authority to find out whether the construction project can be approved and to clarify any questions regarding other building regulations such as distance regulations, noise protection, environmental and nature conservation concerns, or monument protection regulations. In addition, small wind turbines must be registered in the Federal Network Agency's Market Data Register. Before commissioning a small wind turbine, there is also a mandatory notification to the responsible grid operator, which is usually carried out by the commissioned electrician. Although consent from neighbors is not required, it is advisable to involve them in the project to rule out potential disputes from the outset.
Construction of a small wind turbine
The construction of a small wind turbine involves several phases, beginning with site preparation. This includes marking and securing the construction area and preparing the foundation. A solid foundation must ensure the stability of the turbine and absorb the loads caused by wind forces. To avoid structural hazards, it is advisable to involve a qualified structural engineer to construct the foundation. After the foundation is laid, the mast is erected and the turbine is installed. This requires special lifting and assembly equipment, as well as expertise to ensure that all components are correctly installed and connected. Electrical wiring and connection to the power grid are important steps that ensure the efficient use of the generated electricity. The wiring and connection of the turbine to the local power grid must be carried out by professionals in accordance with applicable standards. Before the turbine is commissioned, extensive testing is required to ensure that all systems are functioning properly. This includes mechanical testing, electrical testing, and verification of the control systems. Only after these tests have been successfully completed can the turbine be officially commissioned.
Challenges and risks when building a small wind turbine
Technical problems and potential sources of error can be minimized through careful planning and quality control. Regular inspections during the construction phase and the use of high-quality materials help prevent defects. Safety measures must be observed throughout the entire construction process. This includes training personnel in dealing with specific hazards and implementing safety regulations to prevent accidents. Financial risks can be reduced through careful budget planning and risk management strategies. These include considering cost buffers and insurance coverage. TWE can help minimize these risks and provide comprehensive support services.
Maintenance and operation of a small wind turbine
Regular service and maintenance work is required to maximize the performance and service life of the turbine. This includes inspection and testing of the foundation and tower structure, rotor blades, testing of mechanical and electrical components, and possible updates to the control software. A well-maintained turbine can provide reliable energy for many years. TWE offers a comprehensive maintenance service that includes regular inspection and maintenance of the turbine. This ensures that the turbine is always in optimal condition and delivers its maximum performance. ```
The careful planning of the small wind turbine is always in focus
Careful planning is crucial to maximize the efficiency and economic viability of a small wind turbine. Important elements include a thorough site analysis, consideration of legal requirements, and careful selection of the small wind turbine. Future challenges and opportunities in this area lie in the further development of technology and improved economic viability. Continuous innovation and research in the field of small wind turbines will help further promote the use of this sustainable energy source and make its benefits widely available.
