Wind Power: Yesterday, Today, Tomorrow
Historical background in brief
People have been using wind power from the time immemorial.
Originally they learnt to transform kinetic energy of wind stream into mechanical one. There appeared lots of different wind mills making men’s life much easier in those times.
An idea of a wind turbine for electric power generation using wind power started up around 100 years ago.
Inventors created wide range of various types of wind power generator designs:
– by axis (horizontal, vertical, inclined);
– by number of blades (one, two, three and more);
– by capacity (from tens W to several MW);
– by blade design, by generator design etc.
But in an attempt to raise WTG’s capacity inventors faced new problems:
1. Mechanical properties of materials modern wind generators are made of become serious constraints due to the generators’ size and dynamic loads they bear. Further expanding capacity (size) of wind generators calls for application of the latest which means more expensive materials which is reflected on the rise of prices of generated power that are rather high even without that.
2. Wind generators of higher capacity require higher wind speeds. Nowadays it becomes more and more difficult to find areas for construction of wind farms but people require more and more power.
Today wind energy market grows up to 30% annually. But with wind power generation enthusiasts along there lately appear more and more skeptics. Wind power generation being clean and using renewable sources has number of substantial disadvantages: low quality of generated power, TV and radio signals interference, bad sound influence on fauna and need in additional reserve power generating capacities of traditional design etc.
More and more people being worried about negative trends in wind energy generation reasonably ask such questions as: What are the prospects of wind power generation? Will wind power generation take economically significant place in world economy? Will the investments in wind power generation be fruitful etc.?
World oil and gas market situation stimulates development of power generation using renewable sources. High price and low quality of such electric power does not make estimates of wind energy generation prospects more optimistic.
People need new reliable sources of electric power meeting following requirements of today’s life:
1. Low price of generated power
2. High quality of generated power
3. Power output should satisfy constantly growing demand
4. Clean power generation
One of the alternative power generation solutions meeting most of the requirements mentioned above is presented below.
Everything new is long forgotten old
Wind energy generation is fundamentally based on two elements: energy source (wind) and energy receiver (wind turbine generator).
Since first steps in wind power development and until now inventors have been improving energy receiver but energy source (wind) has been considered to be a gift of nature that is beyond any control.
In many ways it reflected in various disadvantages of modern wind power generation.
In technical system “wind – wind generator” both elements are equally important.
Only control over all elements of a system allows reaching highest working efficiency.
Improving energy receiver they dropped an idea of controlling wind for no need. But in vain!
Level of modern technical development allows arrangement of quite an effective control over such systems.
We decided to develop a brand new technical system which could allow controlling both energy source as well as energy receiver. Using men’s experience and knowledge in construction and operation of wind generators we can sufficiently increase their working efficiency by controlling of air flow parameters (energy source).
One of the results of our long year researches and tests is a tower wind turbine. It gives a possibility more or less to control all the elements of the system “wind – wind generator”.
Tower wind turbine consists of the following main elements: energy collecting device, generator, energy concentration device and control system.
Energy collecting device is designed as a vertical cylinder the walls of which are framed of profiles making end-to-end channels connecting outer side of the cylinder with its inner vertical channel (input convergent channels). Their aim is to “catch” incoming air flow and turn it vertically up along the vertical axis of the unit and to send it to generator blades.
Generator with blades is places inside the energy concentrating apparatus. Generator transforms kinetic energy of wind into electrical one.
Energy concentrating device is contractually designed as a vertical hollow tower inside dimensions of which converge in the central part where the generator is placed. Inner part of the tower is continuation of the vertical inner channel of the energy collecting device. Such design allows concentration of kinetic energy of wind on generator blades.
Control system (is not shown in the picture) provides timely opening of convergent channels of the tower from the side of the incoming wind and closing of all the other convergent channels.
What are principal differences between tower wind turbine and conventional wind generators, transforming energy of incoming air flow?
1. It allows controlling wind energy concentrating on generator blades.
2. Rotor blades do not need to be “tuned” to wind. Vertical axis generator is fixed in the upper part of the unit. Wind is “tuned” to the generator itself owing to design of the energy collecting device.
3. Speed of wind rises significantly when it reaches generator blades. Design of the energy concentrating device allows raising wind speed in the inner vertical channel of the unit increasing its capacity accordingly.
Experimental tests of the unit models in aerodynamic tunnel showed growth of power output of the generator placed inside the tower more than 4 times, and at low wind speeds – more than 10 times.
To prove received results a 100:1 scale production prototype was constructed. Diagram of comparative tests is similar to laboratory tests diagram.
Analysis of received results shows significant efficiency growth of the generator placed inside the concentrating tower in comparison with wind generators of conventional design:
– Wind initial velocity is 2 times lower;
– Rated wind speed is 2 times lower;
– Utilization factor of installed equipment can reach 0,6…0,7 (was calculated) ;
– Power output is 2-3 times higher;
– 5 times more energy is collected from wind stream area unit at all wind speed ranges, at low speeds – more than 10 times;
– Area of allotted land per unit of rated capacity of the TWT is the lowest among all types of generation.
Tower wind turbine concentrates wind energy on generator blades like a lens collecting sun light into the focus.
Design features of the TWT allow elimination of various disadvantages of conventional wind generators:
1. Noises and radiation harmful for people that can appear during operation of the generator of the TWT do not leave the tower as generator and blades are placed inside of it. Modern materials allow reduction and absorption of harmful noises and vibrations. For the same reason generator and blades of the TWT do not interfere TV and radio signals.
2. TWT can not cause any injuries for birds. To prevent birds from getting onto generator blades one may place protective nets at the entry to the convergent channels. To avoid birds clashing into the TWT at night its outer surface is lighted. It could also improve tower’s appearance.
Technical characteristics of the TWT surpass all the modern convention wind turbine generators using incoming air flow.
Tower wind turbine can be a worthy substitute for conventional wind turbine generators:
– TWT can work at low wind speeds.
– TWT allows reaching larger power output.
– TWT’s effectiveness is in no way lower than that of conventional power stations using carbon fuel such as: gas, coal, black and crude oil and its ecological cleanness has no analogues.
– TWT becomes very effective in areas with low wind speeds.
– Area of allotted land per unit of rated capacity of the TWT is the lowest among all types of generation
– Due to its compactness TWT can become an autonomous self-sufficient power source.