Today, the worldwide wind power capacity is estimated at 840 GW (1). In comparison, Europe now has 236 GW of wind capacity and is expected to install 116 GW of new wind farms over the period from 2022-2026 (2). Thus, Europe is leading the transition towards renewable energies and the number of wind turbines worldwide is on the rise.
How do wind turbines work? The functioning principle is simple. Wind turns the turbine’s blade around a rotor, which spins a generator (mechanical power), which creates electricity. The specific design of the blades allows to maximize the operating time of the turbines and thus the generation of electricity (3). Based on this principle, two types of wind farms are identified: onshore and offshore wind farms.
Onshore wind farms are located on land, while offshore wind farms are in water near the coasts. Both technologies have their advantages and drawbacks. Onshore wind farms are easily connected to power grids and are far less expensive than offshore wind farms. Consequently, last year 81 % of new wind installations in Europe were onshore (2). Nevertheless, they are often criticized for their noise pollution, their impact on the environment and their low energy efficiency. For information, in 2020 onshore wind turbines in France produced 26,3% of their full energy capacity, while offshore wind turbines produced around 40% (4). As highlighted by these numbers, offshore wind farms are more consistent in their capacity to generate energy (wind speed is higher and more consistent in water). Nevertheless, their installation remains low in 2022 due to their high price (hard access and connection to the grid) (5).
Finally, according to a Life Cycle Analysis conducted in 2019 by Piasecka et al., onshore wind turbines have an overall more adverse environmental impact due to the use of rare materials, their installation, operation, and maintenance processes (6). Thus, a challenge in the coming years will be to reduce the installation/maintenance price of offshore wind turbines to switch from onshore to offshore. The development of new technologies might help in that sense (7).
- Piasecka, I., Tomporowski, A., Flizikowski, J., Kruszelnicka, W., Kasner, R., & Mroziński, A. (2019). Life cycle analysis of ecological impacts of an offshore and a land-based wind power plant. Applied Sciences, 9(2), 231.
- Kaldellis, J. K., & Kapsali, M. (2013). Shifting towards offshore wind energy—Recent activity and future development. Energy policy, 53, 136-148.