BLOG: Wind power: How to make wind turbines more efficient

The Global Wind Energy Council claims that the global wind-power capacity will make up one fifth of the global electricity supply by 2030.1 Wind power is therefore a potentially major source of renewable energy for the world, and it is vital that it be utilized to its full extent. The vision is therefore making wind turbines more efficient, durable and reliable so as to produce clean, renewable, wind energy to all people regardless of where they live.

Presently, in big cities where there is a high density of people, there is a relatively small amount of land. Wind turbines are therefore currently unable to supply sufficient energy to people in cities due to the wind-power efficiency being low,2 especially for the smaller wind turbines that fit into urban environments. The amount of land available for wind turbines in cities is unlikely to change, but wind turbine efficiency can be improved so as to provide energy to people no matter where they live. According to research from 2010, the maximum efficiency of a wind turbine is 59.3%.3 Therefore, there is a lot of opportunity to improve efficiency and utilise this renewable resource of energy.

There are many different approaches to making wind turbines more efficient and durable. For example, a Spanish engineering company has designed blades for small wind turbines which, compared to other small wind turbine blades, are more aerodynamic, at a better angle to the wind and wider.4 Other Spanish researchers have developed an algorithm that tells the turbine how to adjust to varying conditions by matching the rotations of the turbines to the wind speed.5 Currently, however, the algorithms do not have the capacity to adjust to different situations and, as wind turbines will be located in different environmental conditions, the turbine must be able to adjust. Elsewhere, a Dutch company has researched noiseless shell-shaped wind turbines that put the turbines at the optimum angle towards the direction of the wind.6 All of these approaches are for small wind turbines, however, which are almost always located in suboptimal wind conditions. Consequently there is only potential for low impact.

Using radar technology

Weak points in the blades of the wind turbines can cause huge upkeep costs over the lifetime of a wind turbine.7 According to a team in Germany, this problem can be solved using radar technology.1

Some background information about wind turbines: Rotors usually have three blades attached1 and, as shown in Figure 1, transform the kinetic energy of the wind to mechanical energy of the blades and a generator generates electricity.8 The blades must be designed to withstand large loads and elastically absorb energy (so that the material returns to its original shape when deforming forces are removed9,1). The blades are therefore made from glass fibre and carbon-fibre-reinforced plastics.7 Problems arise when numerous sheets of glass fibre are layered and glued on top of each other for each blade.1 For this, the glass-fibre sheets must be flat before they are attached so no lumps or folds arise.1 Radar technology detects any faults at high depth resolution and accuracy.7 Using expert software, a 360-degree view of the blade is formed from the material scanner that contains the radar technology.1 Faults are documented to a higher accuracy and precision than other methods (e.g. ultrasound).7

Radar technology can also decrease the ‘downtime’ of wind turbines by avoiding the current lengthy process of manual testing to check for defects (e.g. from birds flying into the wind turbines).10 Upkeep costs are therefore reduced because the problem of getting to the turbine—which can be expensive and time consuming, particularly when the wind turbine is in the ocean—and manually testing the turbine is eliminated.

Radar technology has advantages over other solutions since it helps make the wind turbines more efficient, more durable, and more cost effective all at once. It also allows more of the current wind turbines to be used, rather than using more resources to produce new ones. Building and setting up new wind turbines generates carbon dioxide and burns fossil fuels because of the transportation involved.11

This is a relatively new technology, however. As such, there hasn’t been sufficient time to properly test it. It’s therefore likely that more testing will be required before this technology can become a large scale, global success. It’s also currently unknown how big of an impact this radar technology could make on the wind turbine efficiency. Nevertheless, it is known that the efficiency will increase,10 which is important.

In the future, resolution of the radar blade 360-degree view will be enhanced, improving efficiency further.1 Compared to some other approaches to improving wind turbines, radar technology improves the efficiency and also reduces upkeep costs.

Overall, radar is an exciting new approach for wind turbines that should be taken seriously. If the technology can be implemented globally, the viability of wind turbines will be greatly improved. By improving the efficiency, durability and reducing the upkeep costs, it should be easier for companies to persuade governments to invest in wind turbines, thereby increasing the quantity of renewable energy, decreasing carbon dioxide emissions, and slowing the effect of climate change.

References

1. Loughran, J. Flaws in wind turbine blades detected with radar vision. https://eandt.theiet.org/content/articles/2017/04/flaws-in-wind-turbine-blades-detected-with-radar-vision/ (accessed 9 November 2017).
2. Wind Turbine Facts. Efficiency of Wind Turbines. http://www.windturbinesfacts.co.uk/efficiency.html (accessed 15 November 2017).
3. Rapin A, Commet S, Monroe A, Hendley J, Pourmovahed A. Design and testing of horizontal axis wind turbine blades and components to increase efficiency. InEnergy (IYCE), 2015 5th International Youth Conference on 2015 May 27 (pp. 1-10). IEEE.
4. Loughran, J. Energy generation for miniature wind turbines boosted with super-efficient blades. https://eandt.theiet.org/content/articles/2017/01/energy-generation-for-miniature-wind-turbines-boosted-with-super-efficient-blades/ (accessed 9 November 2017).
5. Pultarova, T. Algorithm improves efficiency of small wind turbines. https://eandt.theiet.org/content/articles/2014/03/algorithm-improves-efficiency-of-small-wind-turbines/ (accessed 9 November 2017).
6. Pultarova, T. Noiseless shell-shaped wind turbine for households unveiled. https://eandt.theiet.org/content/articles/2014/05/noiseless-shell-shaped-wind-turbine-for-households-unveiled/ (accessed 9 November 2017).
InEnergy (IYCE), 2015 5th International Youth Conference on 2015 May 27 (pp. 1-10). IEEE.
7. Fileedge. Using Radar Technology To Increase Wind Turbine Efficiency. http://www.fileedge.com/using-radar-technology-increase-wind-turbine-efficiency/ (accessed 18 November 2017).
8. Watson, D. Wind Turbines and the Energy in Wind. http://www.ftexploring.com/energy/wind-enrgy.html (accessed 19 November 2017).
9. Khan Academy. What is Hooke’s Law?. https://www.khanacademy.org/science/physics/work-and-energy/hookes-law/a/what-is-hookes-law (accessed 24 November 2017).
10. Science News. New radar scanner tests wind turbine blades for defects. https://www.sciencedaily.com/releases/2017/04/170410085314.htm (accessed 18 November 2017).
11. eurostat. Wind Energy. http://ec.europa.eu/eurostat/web/environmental-data-centre-on-natural-resources/natural-resources/energy-resources/wind-energy (accessed 19 November 2017).

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