Accelerating deployment of offshore wind energy alter wind climate and reduce future power generation potentials

Abstract

The European Union has set ambitious CO2 reduction targets, stimulating renewable energy production and accelerating deployment of offshore wind energy in northern European waters, mainly the North Sea. With increasing size and clustering, offshore wind farms (OWFs) wake effects, which alter wind conditions and decrease the power generation efficiency of wind farms downwind become more important. We use a high-resolution regional climate model with implemented wind farm parameterizations to explore offshore wind energy production limits in the North Sea. We simulate near future wind farm scenarios considering existing and planned OWFs in the North Sea and assess power generation losses and wind variations due to wind farm wake. The annual mean wind speed deficit within a wind farm can reach 2–2.5 ms−1 depending on the wind farm geometry. The mean deficit, which decreases with distance, can extend 35–40 km downwind during prevailing southwesterly winds. Wind speed deficits are highest during spring (mainly March–April) and lowest during November–December. The large-size of wind farms and their proximity affect not only the performance of its downwind turbines but also that of neighboring downwind farms, reducing the capacity factor by 20% or more, which increases energy production costs and economic losses. We conclude that wind energy can be a limited resource in the North Sea. The limits and potentials for optimization need to be considered in climate mitigation strategies and cross-national optimization of offshore energy production plans are inevitable.

Climate Change in the Baltic Sea Region: A Summary

“…Although projections of future winds are uncertain, the number of off-shore wind farms can be expected to increase due to the politically driven shift to renewable energies, and the limited space and low acceptance for wind mills on land. Offshore wind farms may in turn affect the regional climate by absorbing atmospheric energy on the regional scale (Akhtar et al, 2021), but the magnitude of this effect is uncertain (Lundquist et al, 2019).…”

Human impacts and their interactions in the Baltic Sea region

“…In contrast, Wang and Prinn (2011) and Huang and Hall (2015) found a potential cooling effect in the vicinity of the offshore wind farms due to an increase in latent heat flux. Airborne observations confirm that wind farm wakes can extend 50-70 km under stable atmospheric conditions (Platis et al, 2018;Akhtar et al, 2021). These https://doi.org/10.5194/esd-2021-54 Preprint.…”

“…Moreover, the variability and expected technological development in turbine effectivity are expected to be larger than the estimated climate effects (Tobin et al, 2016). Irrespective of future wind conditions, problems regarding wind wake effects are to be expected in very 1735 large wind farms, with consequences for the efficiencies of these large farms (Akhtar et al, 2021).…”

“…• There may be a certain impact on the regional climate (+) by offshore wind farms through absorbing atmospheric energy. There is little information on the magnitude of this effect, and modelling exercises have found varying impacts 1770 on the regional climate at current densities of wind warms (Fitch et al, 2013;Vautard et al, 2014;Akhtar et al, 2021). Considerable impacts cannot be excluded in the future with an extensive development of renewable energy production to meet climate goals.…”

Projected Near-Surface Wind Speed Trends in Lithuania

“…Because of this reason, wind power plants should be planned and designed with care. The pay-off period is going to be longer than expected while planning [38,39]. The current investigation shows that the best region for wind power plant building in Lithuania is the coastal area, where a wind speed increase was projected.…”