IEA (2019), Tracking Power, IEA, Paris https://www.iea.org/reports/tracking-power-2019
Onshore wind-generated electricity increased an estimated 12% in 2018, remaining the largest non-hydro renewable technology and generating more than all the others combined. Generation growth was slower than in 2017, however, following the lower global capacity expansion of 2015‑17 and the return to normal levels of wind generation in Europe after a windy 2017. Globally, onshore wind capacity additions increased by 7% to 46 GW in 2018.
Onshore wind is not fully on track to reach the levels envisioned in the Sustainable Development Scenario (SDS) and therefore needs improvement. Despite a modest recovery in recent years, onshore wind annual additions need to grow much more quickly.
Reaching the SDS level by 2030 would require annual generation increases of 12%, while the IEA forecasts only 8% annually through 2024. To get on track with the SDS, yearly net capacity additions need to expand continuously from 47 GW in 2018 to 108 GW in 2030.
China's onshore wind capacity expansion rebounded from 14 GW in 2017 to 19 GW in 2018 as the government lifted development bans in certain regions in response to relaxing curtailment levels since 2016.
In the European Union, onshore wind growth declined by 20%, with only 7.5 GW becoming operational due to slower growth in Germany and the United Kingdom. The policy transition and auction design issues have created a lull in German project development, while the UK government decided to end its onshore wind auction scheme in 2016.
In the United States, onshore additions rebounded slightly from 7 GW in 2017 to 7.6 GW in 2018. This growth was lower than expected, however, because project development in the first three quarters was much slower due to temporal uncertainties surrounding corporate tax changes.
A rush by developers in India to lock in support under the previous incentive scheme, as well as the decrease in an accelerated depreciation incentive, resulted in record-level wind additions in 2017. However, deployment levels in 2018 almost halved to 2.4 GW due to uncertainties in the policy transition to competitive auctions.
Increased efforts in wind technology R&D are essential to realising the SDS, with a main focus on reducing the investment costs and increasing performance and reliability to reach a lower unit cost of energy. Good resource and performance assessments are also important to reduce financing costs. Wind energy technology is already proven and making progress, and while no single element is like to dramatically reduce costs, taken together improvements can ensure the cost trajectory is maintained.
In particular, innovation efforts are needed to aid in resource planning that minimises the impact of scaling up wind power capacity, and system-friendly integration of wind power through digital solutions and advanced power electronics.
Wind power generation creates well-known challenges for electricity grids and power systems through its variability and uncertainty and distributed nature. Wind power plants in many cases already contribute to their own integration through a range of upgrades, but their contribution will need to be ramped up in the SDS through a combination of regulation and grid codes and more innovative solutions for providing ancillary services and other services related to dispatchability.
Wind farm planning, both onshore and offshore, will require enhanced sensitivity assessment of the surrounding environment to ensure long term turbine efficiency and attractive return on investment.
Large rotor diameters and higher hub heights have higher upfront and per unit power costs but increase production and decrease costs per unit energy while making better use of the resource and decreasing variability of output.