The Future for Wind Farms May Lie In Compact And Efficient Vertical Turbines

The now-familiar sight of conventional propeller wind turbines might be substituted in the years to come with wind farms consisting of an extra compact and efficient vertical turbine design.

A new study from Oxford Brookes University has found that the vertical turbine concept is far more effective than conventional turbines in large-scale wind farms. When arranged in pairs, the vertical turbines enhance each other’s efficiency by as much as 15%.

Researchers from the School of Engineering, Computing, and Mathematics (ECM) at Oxford Brookes led by Professor Iakovos Tzanakis carried out an extensive investigation utilizing more than 11,500 hours of computer simulation to demonstrate that wind farms can perform more efficiently by replacing the conventional propeller-type Horizontal Axis Wind Turbines (HAWTs), with compact Vertical Axis Wind Turbines (VAWTs).

The superior efficiency of vertical turbines

For the first time at a practical scale, the investigation demonstrates the potential of large-scale VAWTs to outcompete present Horizontal Axis Wind Turbine (HAWT) farms.

VAWTs spin around an axis vertical to the ground and display a different behavior of the widely known propeller design (HAWTs). The investigation found that VAWTs enhance each other’s efficiency when organized in grid formations. Placing wind turbines to maximize outputs is critical to the design of wind farms.

Professor Tzanakis commented on the subject, saying that the research shows that the future of wind farms should be vertical. Vertical axis wind farm turbines can be developed to be significantly closer together, enhancing their performance and ultimately reducing electrical power costs. In the future, VAWTs can assist in speeding up the eco-friendly shift of our power systems to ensure that more clean and sustainable power comes from renewable sources.

With the UK’s wind power capacity predicted to almost double by 2030, the results are a stepping stone in designing more efficient wind farms, comprehending big scale wind energy harvesting strategies, and eventually enhancing wind power technology to faster substitute fossil fuels providers of energy.

Meeting wind power goals

Ads stated by the Global Wind Report 2021, the planet needs to be installing wind power three times faster over the following ten years so as to comply with net-zero targets and prevent the worst effects of climate change.

Lead author of the paper and Bachelor of Engineering graduate Joachim Toftegaard Hansen said that modern wind farms are among the most effective solutions to produce green energy. On the other hand, they have one primary problem: as the wind comes close to the front row of the turbines, turbulence will be produced downstream. The turbulence is harmful to the efficiency of the subsequent rows.

Hansen continued by saying that, put simply, the front row will convert around half the kinetic energy of the wind into electrical energy, whereas for the back row, that number is down to 25-30%. Each turbine is priced at more than ₤ 2 million/MW. Hansen added that, as an engineer, it naturally struck him that there should be a more economical method.

The research is the first to comprehensively evaluate several facets of wind turbine performance regarding the direction of rotation, array angle, number of blades, and turbine spacing. It is, in addition, the first study to explore whether the efficiency enhancements apply for three VAWT turbines assembled in a series.

Dr. Mahak, co-author of the paper and Senior Lecturer in ECM, said that the relevance of using computational techniques in understanding flow physics could not be underestimated. These concept and improvement studies are a portion of the cost compared to the substantially massive test centers. This is especially important at the preliminary design stage and is incredibly helpful for the industries attempting to attain the best design efficiency and power output.

Reference: “Numerical modelling and optimization of vertical axis wind turbine pairs: A scale up approach” by Joachim Toftegaard Hansen, Mahak Mahak and Iakovos Tzanakis, 4 March 2021, Renewable Energy.
DOI: 10.1016/j.renene.2021.03.001