The problem of energy transfer is the most important in the wind turbine generator. If you look at any project, it is the method of energy transfer that is decisive for the rest of the layout.
The Magenn project initially looked like the ideal solution, but it was the lack of attention to the transmission method that led to the closure of the project. The weight of the electric cable turned out to be so great that when the task was to transfer kilowatts, the more megawatts of energy, the lifting capacity of the balloon became catastrophically scarce.
Let’s list the known possibilities of energy transfer, including exotic ones (I do not pretend to have a full list, I hope they will help me), as well as brief comments:
1.The mentioned transmission of the electric wire by direct or alternating current.
Electricity losses are quite significant. You can reduce losses by increasing the cross-section, but this greatly increases the weight of the cable. Also, to reduce losses, an increase in voltage is possible, but this requires a powerful and heavy transformer at the point of the catcher.
For an estimation I will give an example: at a voltage 380в 10кВт a section of a copper cable 2,5мм х 3 at a cable length 500м weight of copper will make 32кг. To this we need to add a braid and a transformer.
High-frequency electricity of high voltage along the waveguide.
As already mentioned, a heavy transformer is required to convert the voltage, the mass of which increases with the conversion factor. In the case of creating a waveguide (transfer of energy according to the Tesla principle), there is a great danger of a lightning discharge, or a weaker static voltage. Experiments with a fatal outcome are known.
Mechanical draft of a large period (5 … 10 min.) With a winch.
The most popular way at the moment is the transfer of energy in AWE projects. The disadvantages include:
– cable rewiring;
– unstable energy production due to constant altitude change;
– relative low work height;
– the existence of a long phase of the lack of energy production and even reverse consumption.
At the same time, the mechanical transmission method is the most energy efficient of the calculation per kilogram of weight of the retaining cable.
High-frequency mechanical vibration (reciprocating motion of the cable).
A positive property is the stationarity of the flying apparatus.
Experiments have shown the impossibility of transferring energy to certain amplitudes in connection with the inertia of the sagging wire.
Large frequencies have not been investigated, a more positive effect is assumed.
There are experiments of Japanese inventors on transferring thus energy from the satellite. This technology is very expensive and dangerous in case of a beam shift from the receiving device.
Raising-lowering containers with energy storage.
In connection with the development of electric vehicles and quadrocopters in the past few years, the amount of energy stored per kilogram of weight has increased dramatically. This technology becomes the most competitive in comparison with mechanical thrust. This method can be referred to as electroaccumulators, and hydrogen generators.