Supporters of alternative energy supply today are offered a variety of solutions – from solar panels to wind turbines, whose output reaches several thousand kilowatt-hours per year. The latter option enjoys well-deserved popularity. Our fellow citizens prefer to take the example of Europe, where the use of wind energy has reached an industrial scale and in some areas has almost replaced the centralized power supply. And they should be taken into account when choosing and calculating the payback period of a wind turbine generator, so that the expensive device will justify the investment and bring tangible benefits.
Peculiarities of wind turbines application
For the device to work at full capacity and managed to surpass its nominal characteristics, it is recommended to install it at a high altitude – about 30-40 m, where wind gusts are stronger than at the ground surface. In the conditions of dense buildings, it is problematic to meet this requirement. Therefore, the height should be calculated by adding about 4-5 m from the surface of the tallest building near the site for the generator. Optimal place of its installation is the steppe or an area without vegetation with a radius of about 200 meters relative to the point of installation.
Given the intermittent nature of winds, the wind generator is best used to power appliances and equipment that do not have special requirements for the quality of energy supply. But it is not recommended to connect directly to the device sensitive devices. As a result of frequent power surges, they will quickly fail. The solution to this problem can be the use of power rectifier, the selection and installation of which should be carried out in accordance with the manufacturer’s recommendations.
Developers of alternative power supply sources strongly advise using the possibilities of uninterruptible power system. Its functions will include accumulation of reserves of “excess” electricity and its supply to the house during a long windless period, when the generator is in the forced idle mode. The basis of the system is a battery, for the timely recharging of which it is necessary to connect a rectifier to the network. It will equalize the indicators of the received energy and reduce the risk of overcharging in case of a sudden jump in voltage with an increase in wind force. And to turn the direct current from the generator into alternating current, suitable for powering household devices, an inverter is installed in the system.
If the region is characterized by multi-day periods of no wind, it is recommended to connect a gasoline or diesel generator to the uninterruptible power system. In the case of complete discharge of the battery and temporary inactivity of the wind turbine, the device will supply the required amount of electricity to the house, and interruptions to the electricity supply will be avoided.
Calculation of the payback of a wind turbine generator
Having invested several thousand dollars in the purchase of the device, the new owner is entitled to count on its obvious benefit and payback on the wind turbine. Let’s try to calculate the price of a kilowatt of electricity on a standard generator model with a capacity of 4-5 kW. At wind speed of 4-5 m/s the device will give about 350 kW per month, or 4200 kW per year. The service life of the generator is about 25 years, the cost of most models of devices – in the range of 4315 dollars. Divide the cost by the product of the annual output and the service life:
4315 / 4200*25 = $0.04
Thus, the cost per kilowatt of energy of the paid-off wind generator will be just over $0,04. Compared to the current price level, there is a benefit, but it is not as great as we would like it to be with alternative energy sources.
The above calculations give a different result if the wind speed is about 7-8 m/s. A 6-7 kW wind turbine will give about 780 kW per month or, 9000 kW per year. With the cost of such wind turbines about, 4778 we get the following result:
4778 / 9000*25 = $0.02
This cost is an obvious benefit, especially for energy-intensive facilities.
To summarize the above: is a wind turbine profitable
The above results clearly prove the payback on the cost of purchasing and running a wind turbine generator. All the more so:
- The cost per kilowatt is constantly increasing due to inflation.
- When using a wind turbine, facility becomes energy-independent.
- “Surplus” generated electricity can be accumulated and stored in case of windless weather thanks to an uninterruptible power system.
- Many facilities, remote from the centralized power supply network, are forced to exist in the absence of electricity, as their connection is unprofitable.
So, the wind generator is profitable. Its purchase for power-intensive consumers without power supply is economically feasible. Hotel in the countryside, an agricultural farm or livestock enterprise, cottage community – in any case, the cost of connecting an alternative power supply will be justified. It remains only to choose a suitable model of wind turbine and install it, guided by the recommendations of the manufacturer. The power of the device should match the average wind speed in your area. It can be clarified by a special wind map or according to the local weather station.
Please note: for wind turbines from Chinese manufacturers, the rated capacity of the device is calculated taking into account the wind speed of 50-70% of the ground level. It is problematic to install a wind turbine at such a height. Too high a mast is expensive, and there are strict requirements for its strength. In addition, at this height, wind gusts form strong eddies. They not only slow down the wind turbine, but can also cause the blades to break. The solution – install the device at a height of 30-35 m, which will provide access to the strong wind, but exclude the breakage of the wind turbine.