Wind Turbines: Questions and Answers
Answers to the most frequent customer questions about the ElvWiS® wind turbines and their operation.
For which areas of application are the ElvWiS® wind turbines suitable?
The wind turbines are suitable for the efficient generation of electricity in places that are often not connected to the public power grid. This can be e.g. Campsites, measuring stations, remote buildings (mountain hut, garden shed) or boats. On the one hand, the turbines can be installed stationary and, due to their compact dimensions, low weight and efficient operation, are also suitable for mobile applications. The advantage of these usage variants results from the self-sufficient power generation, in which there is no connection to the public power grid or this is simply too expensive and/or too labor intensive in comparison.
In principle, feeding into the power grid or supporting home supply is possible, but at the moment it is at least financially not profitable in relation to the purchase price. However, if in such an application case the energy sypply takes place primarily for environmentally conscious and future-oriented reasons, then this is exemplary and welcome in view of a low-emission future. Here applications variants make sense, for example, where it is important to generate as much energy as possible yourself and from known environmentally friendly sources or to store the generated energy yourself and then use it for own use.
What advantages do ElvWiS® wind turbines offer in terms of energy generation?
The user often has to deal with very different wind conditions at different locations. Our wind turbines were consequently developed so that they can produce electricity efficiently even at low wind speeds and remain operational even at high wind speeds. In addition, strongly changing wind directions are used sustainably for energy production. The background of this concept is the highest possible energy yield at various locations throughout the year.
The performance values of our turbines often appear at first glance to be relatively low due to the comparatively small rotor areas, but when looking at the medium and long-term energy production, the picture is completely different. Knowing that pure maximum power values do not allow a good estimate of the long-term energy yield, we deliberately avoid specializing our turbines in the low or high wind design. The strengths of our turbines lie primarily in the universal application for a wide wind force range and demanding wind conditions as well as in a high as possible system efficiency. The seemingly disadvantage of the relatively low maximum power values compared to other, mostly larger turbines is effectively converted into an advantage in the medium and long term by the combination of these properties.
How loud are the ElvWiS® wind turbines in operation?
Assuming that the installation of the turbine and the adjustment in the holder has been carried out correctly, the turbines are virtually inaudible compared to the surrounding wind noise. The wind noise heard in many of our videos is generated solely by the wind on the camera's unprotected microphone. The generator of the turbine can produce a quiet whirring during operation, which is typical for electric generators in power production. For real wind energy fans, this sound is also a sure and good sign that they are currently receiving free energy.
How do the ElvWiS® wind turbine models and series differ?
The design of the wind turbine results largely from the conditions of use and then from the personal requirements and capabilities of the user. Particularly suitable for mobile use are the ADVENTURE models, which can be easily assembled and connected, and there are also various demountable variants that are very easy to transport. The ALUMINUM models are primarily designed for permanent installation, although there are also fixed variants of ADVENTURE turbines. For the ALUMINUM models, you need a little manual skill in the assembly, the electrical connection and the adjustment, this is largely eliminated in the ADVENTURE models. If you just want to have as much power as possible, then you are well supplied with the large ALUMINUM models. The ALUMINIUM hybrid models are ideal if you need a turbine for permanent installation that combines all the design advantages of the ALUMINUM and ADVENTURE series. Here are important features, such as a user-friendly assembly, highest performance and excellent material quality vividly combined.
About features such as quality, appearance, conspicuousness, etc., you can decide according to your own wishes based on the specific article descriptions. As a small help, we have created under "Help/Information" the page "The right Wind Turbine - Product Finder", where we will try to guide you to specific questions about the best choice of your wind turbine.
What performance can be expected from the ElvWiS® wind turbines?
First of all, the performance of a wind turbine is generally dependent on its design, the associated efficiency and then primarily on the available rotor surface and the wind supply. The mechanical power of the turbine thus results from the size of the rotor and its efficiency. Our brushless and cogging-free disc generators are optimally matched to the respective rotors and achieve efficiencies up to 96% when converting the mechanical power into electrical energy, which is a very good value.
For an exact estimation of the expected performance you will find under „Help/Information" the "Power Calculator for Wind Turbines"; on this page we provide you with the model-typical surface dimensions and efficiencies, with which you can play through using the linked performance calculator all imaginable combinations of different parameters. In our article descriptions, we only specify the rotor power that the rotor can convert into mechanical energy under optimal conditions, as the actually delivered electrical power can vary greatly depending on e.g. the load, charge controller and state of charge of batteries. Also note that the location and environment of the turbine significantly affect the wind conditions; The highest possible performance can only be achieved with a free wind access without turbulences.
Important: The rotor performances given by us are not to be confused with the generator power, with which the indicated power values refer to the generator operating condition under full load with power adjustment.
What is the energy yield that can be gained from the wind?
The maximum achievable power of the wind energy is 59% according to Betz. Depending on the degree of efficiency, each wind turbine can convert only a certain proportion into a mechanical and a coupled generator thereof into electrical energy. To get a feeling for the wind power, it is important to know that the energy in the wind increases eightfold when the wind speed is doubled. This means that the turbines can generate relatively little power at low wind speeds, but at higher wind speeds, power production increases dramatically. For this reason, it is decisively that the planned location of the turbine is as accessible to the wind as possible, especially at low average wind speeds.
Can you combine the ElvWiS® wind turbines with solar systems and how does that work?
Yes, that is highly recommended. First of all, solar and wind power complement each other almost perfectly during the year. When there is less sun, there is usually more wind and vice versa. Wind power also has the advantage that it is also available at night, which the solar energy logically can not afford.
If you e.g. operate an existing solar system with a 12 volt battery system, you can easily connect the turbine with the help of our wind charge controller parallel to the solar charge controller. Each system then has its own charge control and is independent by itself. From the point of view of the battery, it does not matter which charge controller it is charged from, whether several regulators charge at the same time or one regulator charges slightly higher than the other. It may be necessary to ensure that the battery system has a sufficiently high capacity, otherwise the battery voltage can be increased so much by the dominant charger, so that the charge controller of the weaker charger detects the battery as full and stops its charging activity. Basically, however, this is also not harmful and enables a good charge even with smaller capacities when solar and wind power alternate during the day or supplement. If you use a battery system with a different voltage than 12 volts, just look at the following response to the battery voltages.
For which battery voltages are the ElvWiS® wind turbines suitable?
In general, the generators of the vertical wind turbines are optimized for a system voltage of 12 volts, for which we offer the right wind charge controller. If you use other system voltages, the solution depends on whether the system consists of 12 volt components. If yes, the charge may be on a single 12 volt component when the charge is distributed to the other battery components via a so-called balance charger/battery balancer. These balance chargers are recommended for the longevity of the battery system anyway, as this is always ensured a balanced battery state of charge. When choosing the balance charger, make sure that it actually redistributes the charge and not, as is the case with some models, destroys the excess charge.
If there are no 12 volt components, the output voltage can be increased with appropriate equipment. These can be voltage cascades or certain step-up/boost charge controllers that are capable of doing so. You can also use our boost charge controller for 24 volt systems that do not consist of 12 volt sub-components. However, you then need higher average wind speeds and/or good wind conditions in order to comfortably reach the starting voltage of 15 volts on the charge controller, which is required for 24 volt systems. In this case, low wind strengths would not be utilized to generate energy.
Which charge controllers can be used for the ElvWiS® wind turbines?
The 12 volt wind charge controller we offer has proven itself for many years and is therefore highly recommended. This wind charge controller contains a rectifier and regulates the charge of the battery, in addition it slows controlled down the speed of the wind turbine with full battery or disconncted battery cables. For other charge controllers, it is important that the input voltage range is wide enough, even the maximum current (Ampere) must be able to be processed.
Many solar charge controllers disconnect the circuit when the batteries are full, etc., which causes the turbines to idle and spin unnecessarily fast. Although the turbines have an automatic speed limitation due to their design, such an uncontrolled operating state is not advantageous with regard to material and longevity. In the case of MPPT charge controllers, the applicability must also be checked on a case-by-case basis, since the mode of operation of a wind turbine is very different from that of a solar panel. For example, the MPPT controls are often too slow to follow the rapidly changing operating conditions. On the other hand, other MPPT controls simply choke the turbine in an attempt to extract the maximum power from the generator.
How do you carry out the electrical connection of the ElvWiS® wind turbines?
In advance: If you are not sure how to do the wiring, be sure to ask someone who knows it or let this be done by a specialist.
Otherwise: Fix the rotor of the turbine. The generator produces a 3-phase alternating current, therefore connect the charge controller/rectifier with all three phases of the generator cable, the order of the three phases is not relevant for this connection. Then connect the cables of the charge controller/rectifier to the battery or to the consumer (red + / black -).
In comparison to a charge controller, a rectifier can also be used for battery charging, but it has no charge state monitoring and does not work as efficiently. Therefore, periodically check the battery level or use a suitable charge status indicator when using the rectifier for battery charging. The rectifier can also be used very well for smaller DC applications.
Use a sufficiently dimensioned (melting) fuse, this fuse must be installed in the positive lead (red) after the respective power converter. Also note the specifications of the charge controller/rectifier. After connecting all cables and inserting the fuse, loosen the rotor to start normal operation.
How can you use ElvWiS® wind turbines to feed into the grid?
On this subject, it is essential that you also note our explanations in the first section "For which areas of application are the ElvWiS® wind turbines suitable?"
First of all: The generators of the turbines generate a three-phase alternating current, but this is completely unsuitable for a direct connection to the power grid, as the alternating current frequency fluctuates with the rotation speed and is not matched to the grid frequency.
In order to feed into the grid, an alternating voltage that is synchronized with the grid frequency is required, which can be generated with a grid tie inverter. In addition, this inverter must be equipped with all common protection mechanisms that are necessary for the country-specific requirements.
A combination of turbine, wind charge controller, buffer battery and a battery grid inverter has proven to be practicable for a well-functioning grid feed. These grid inverters are able to feed the energy directly from a battery into the power grid. Since such inverters also have a certain self-consumption, we always recommend our largest turbine models in order to be able to implement such an application with excess energy. The advantage of the constellation described here is that you can take the generated electricity from the battery yourself at any time and connect several turbines, each with an inexpensive charge controller, to the same buffer battery. You then only need a single, mostly cost-intensive grid inverter. In addition, you can also connect solar panels with appropriate battery charge controllers in parallel to this battery.
A direct feed-in via solar micro inverter does not seem to be efficient at the moment. The input voltage range of these inverters often does not match the output voltage of the turbines and the regulation is usually too slow and tends to stall the turbines. As with a solar panel, the inverter tries to regulate in the direction of maximum power output, which can also be achieved with a relatively simple control strategy for solar panels, since there are no additional mechanical components. In the case of wind turbines, however, this has the effect that the generator is put under maximum load and the turbine is braked down out of the optimum working speed, which makes operation with these inverters very inefficient.
May I operate the ElvWiS® wind turbine on a motorized vehicle while driving?
No, this is not allowed! If you do this anyway, you may endanger yourself and other people. The turbines are designed for operation in normal wind conditions, including strong gusts and high wind speeds in storms. During extremely severe storms, our turbines, like all other movable objects, must be secured. Make yourself aware that at 80 km / h with a vehicle, the turbines are permanently exposed to wind conditions such as a storm. If there is a headwind, this is added to the speed of the vehicle. When the wind speed is doubled, the power in the wind increases eightfold; in the high range, as is known from storms, this can have dramatic consequences.
In addition: Don't waste fuel, your vehicle is not a perpetual motion machine. You have to use much more energy in the form of fuel for the wind energy that you can generate while driving than you can recover from the electricity from the turbine. In this case, your alternator will generate electricity much more efficiently.
The ElvWiS® wind turbine does not seem to work, what can you do?
Normally you have received a detailed instruction manual for your turbine, which contains a detailed and solution-oriented manual for troubleshooting. Please take the time and work through the points mentioned systematically, often there are only minor things that lead to the solution of the problem. If, despite intensive search, you can not narrow down the problem or solve it, we will be happy to assist you in any case.
How can I correctly estimate the wind force without measuring instruments??
Link to the wind force table by Admiral Sir Francis Beaufort (1774 - 1852).
You still have not found a suitable answer to your question?
Call us or use the contact form of the shop. We look forward to helping you.