Frequently asked questions about offshore wind power
Below, we have gathered questions that arise in discussions about offshore wind power, and answers supported by facts and sources.
Vanliga frågor och svar
FAQ
Does wind power create emissions?
Wind power, unlike fossil energy production, does not generate any emissions during operation. According to the Swedish Environmental Protection Agency (Naturvårdverket), it is essential to identify emission factors in the production chain of activities, to analyze the total amount of emissions throughout the life cycle. All energy production creates emissions during:
- Raw material extraction.
- Construction.
- Placement.
- Maintenance.
- Decommissioning.
A common way to analyze emissions in electricity production is to measure in grams of carbon dioxide equivalents per kilowatt-hour produced. According to the Swedish Energy Agency (Energimyndigheten 2022), the greenhouse gas emissions from different energy production sources throughout the life cycle can be ranked as follows:
- Hydropower ~4 g CO2e/kWh
- Wind power ~11 g CO2e/kWh
- Nuclear power ~12 g CO2e/kWh
- Solar power ~41 g CO2e/kWh
- Natural gas 290-930 g CO2e/kWh
- Oil 510-1170 g CO2e/kWh
- Coal 740-1689 g CO2e/kWh
These calculations vary depending on the technological development of individual power plants.
How does wind power affect marine life?
All activities have an impact on the environment. When establishing offshore wind power, it is important to balance the benefits of renewable energy production with the least possible negative impact on wildlife and the environment. Environmental impact assessments are conducted during the project's planning phase to identify and mitigate potential environmental effects.
"Vindval" is a research program that conducts wind power-related studies on people, nature, and the environment. The program is a collaboration between the Swedish Energy Agency and the Swedish Environmental Protection Agency. Vindval has produced a synthesis report on the effects of offshore wind power on marine life during the various life cycle phases of wind turbines. According to the report, the most significant disturbances were observed during the construction phase, in the form of underwater noise and sediment disturbance (the noise is influenced by the type of foundation). The noise can affect the behavior patterns of sound-sensitive species, and the sediment disturbance can lead to habitat changes.
Offshore wind power can also have positive effects on marine life. The fixed structures can create reef-like effects, providing habitats for sessile species. Over time, this can contribute to the aggregation of marine life around the structures.
Read the full report on the Sedish Environmental Protection Agency's website (In Swedish)
How does offshore wind farms affect birds and bats?
It is well documented that wind turbines and larger infrastructure can pose a threat to birds and bats that fly in the vicinity of wind farms and can become obstacles for flight routes. According to Vindval, it is important to identify flight routes and areas with high bird populations, especially those used for breeding, overwintering, or resting, during the early stages of wind farm planning.
The advantage of offshore wind farms, apart from their distance from significant bird areas, is that seabirds are more likely to avoid flying within areas with wind turbines compared to land-based sites. Deviations in flight routes may result in longer flight distances, but according to Vindval, this does not have a significant effect.
Read the full report on the Swedish Environmental Protection Agency's website (In Swedish)
Do wind turbines create microplastics?
There are studies regarding the wear and tear of rotor blades throughout the lifecycle of wind turbines. The focus area relates to what is known as "leading edge erosion," where the outer contact surface of the rotor blades is subjected to wear during rotation. According to Lopez et al. (2023), the levels of erosion are influenced by harsh weather conditions and the choice of protective coatings used on the blades. The conclusion suggests that the wear primarily affects aerodynamics and production efficiency, rather than the generation of microplastics, which depends on the choice of materials.
Microplastics are plastic particles that are less than 5 millimeters in diameter. These particles come from degraded plastic products that end up in the ocean in one way or another. The discussion on microplastics in the ocean is becoming increasingly relevant as researchers have observed their global distribution in various fish, whales, seabirds, and even humans. Studies show that microplastics have a negative impact on marine life, but further research is needed to understand long-term effects. Current research indicates that the most significant sources of microplastics are consumer products and textiles.
The problem with microplastics is that plastic products exist in all aspects of society, making it challenging to trace the origin of particles after degradation. Wind turbines, like other energy facilities, use plastic materials that could be potential sources of microplastics. However, in studies addressing the issue, the contribution of wind power to microplastics in the ocean is considered very small compared to items like plastic bags, household products, and car tires, among others.
Read more about the different sources for microplastics in EU's factsheet on microplastics.
Read more about leading edge erosion on ScienceDirect's portal for publications:
Read more about microplastics on SpringerLink's portal for publications:
What happens when the wind doesn’t blow?
To enable a 12 MW wind turbine to generate electricity, a wind speed of approximately 4 meters per second is required (varies depending on the size and rotor diameter). This means that there are periods when wind turbines do not produce electricity, which is a challenge for all weather-dependent energy resources. However, according to the Swedish Energy Agency (2021), there is no energy production that operates continuously, as operational disturbances, maintenance, and supply security are factors that affect the production capacity of all energy resources.
The advantages of wind power are that these operational disturbances are often short and easily overcome, whereas other energy sources such as nuclear power take longer to start up in the event of an operational disturbance. An additional positive development for wind power is the potential for further processing the electricity into hydrogen. Hydrogen can be stored, which mitigates the weather dependency of wind power. By selling the electricity generated from wind power when the electricity price is high and further processing the electricity into hydrogen when the electricity price is low, wind power can play a balancing role in the electricity market.
Read more about the conditions for wind power on the Swedish Energy Agency's website (In Swedish)
The Sunnanvind project is led by the Government of Åland. Sunnanvind's mission is to enable offshore wind power in the northern maritime areas, maximizing the benefits for Åland as quickly as possible. The project is conducting preparatory work for the auctioning of the rights to utilize these maritime areas.
