Governments and industries around the world have pledged to reduce their greenhouse gas emissions to zero during the next 2 to 3 decades, supporting the Intergovernmental Panel on Climate Change recommendations to limit the warming of the planet. Decarbonizing the energy sector, shifting the electricity supply to renewable sources within the next 2 decades (Cole et al., 2021; Denholm et al., 2021; IPCC, 2022), is a first step. Projections by leading energy observers (IEA, 2021a; GWEC, 2021; Larson et al., 2020) are that the new electric sector will rely on 70 %–90 % variable renewable generation. The increase in renewables is expected to be roughly split between wind and solar energy. Therefore, to achieve a carbon-pollution-free electricity sector near-term and net-zero greenhouse gas emissions by mid-century, wind energy must increase its contribution to power generation from its current 5 % level of global penetration to supply 35 %–50 % or more of future electricity demand in a highly electrified global energy system (IEA, 2021a).

Clearly, wind will be a foundational energy source in the electricity grid at the heart of a future integrated-energy system, replacing traditional electricity generators powered by fossil fuels and providing grid reliability services in addition to energy (Hodge et al., 2020; Holttinen et al., 2020). Future capabilities and functions of the wind energy sector will evolve apace with the future expansion and needs of global energy infrastructure (e.g., manufacturing green fuels to create demand flexibility and decarbonizing sectors that are difficult to electrify). However, wind turbines, as designed today, will not be able to provide the services needed to form and to stabilize the grid as a majority supplier. Meanwhile, wind power plants will have an ever-expanding footprint that will inevitably multiply social and environmental impacts. Efficiently and affordably deploying wind plants at larger scales, in diverse landscapes, and in deep water offshore will be extremely challenging. The notion that we can simply take hardware that has been successful to this point and multiply the deployment by a factor of 5 or 10 fails to appreciate the harsh reality that the technology demands of the future will be significantly different than they have been to date. The International Energy Agency (IEA) observed (IEA, 2021b) that in moving toward a new energy economy “every data point showing the speed of change in energy can be countered by another showing the stubbornness of the status quo”, which could not be more applicable to wind.

The new energy economy will be more electrified, efficient, interconnected and clean. Its emergence is the product of a virtuous circle of policy action and technology innovation, and its momentum is now sustained by lower costs … At the moment, however, every data point showing the speed of change in energy can be countered by another showing the stubbornness of the status quo (IEA, 2021a).

A review article in Science (Veers et al., 2019) emerged from an IEA Wind Topical Experts Meeting assessing the “Grand Challenges” for wind energy to meet its full potential (Dykes et al., 2019). The Science article condenses the outcome of that workshop to make the case that wind technology has grown to turbine sizes, plant scales, and grid impacts that force a re-evaluation of the very scientific underpinnings of wind energy. Three critical technical challenges emerged: the atmosphere, the turbine, and the plant–grid interaction. Wind energy systems are so intrinsically interconnected that continued progress requires attention to all three challenges – progress in any single area is insufficient. Crosscutting opportunities in digitalization and integrated education of the next generation of researchers and technicians were also noted. The publication quickly elicited two insightful letters to the editor pointing out that the focus on issues of the physical sciences missed the equally critical areas related to environmental impacts (Katzner et al., 2019) and social interactions (Firestone, 2019). In addition, the Small Wind Turbine Technical Committee of the European Academy of Wind Energy (EAWE) assessed the status of small-turbine technologies and identified needs for contributing to distributed energy production; these lie in an entirely different realm of physics and application.

Figure 1This graphic illustrates the generations of wind energy development. Each generation's achievements expanded wind energy's impact (shown in the blue boxes on the left); however, in moving quickly from generation to generation, some underlying science was left unresolved (shown in the white boxes on the right). Generation 1 delivered working energy conversion systems, Generation 2 delivered low-cost and reliable turbines, and Generation 3 is beginning to provide controllable wind plants that support the grid. The aspirational goal of Generation 4 is a carbon-neutral future energy system. Wind can be the foundation for the fourth generation, but not until the gap left behind by the previous generations is addressed. Graphic based on Veers (2022).

The Science article was by design a highly condensed statement of wind energy's progress, potential, and high-level scientific gaps. The need still exists to articulate a more detailed and actionable set of recommendations. The original authors engaged a larger group of experts to review each Grand Challenge in more depth and provide recommendations for how outstanding issues might be resolved, including the environmental and social aspects highlighted by the letters to the editor. In an article clarifying the scientific efforts related to the pandemic, Yong (2021) advises that environmental and social issues are part of the integrated problem. He states, “The pandemic made it clear that science touches everything and everything touches science.” In reality, physical, social, and environmental processes all interact to influence the growth of wind energy. We are only now beginning to appreciate and understand these competing issues, with regard to not only wind energy, but also the range of factors – technology development, policy, public acceptance, economics, public–private partnerships, etc. – necessary to ensure a successful energy transition. Continued research efforts and investments are needed to drive customizable solutions that meet local needs and scale up to achieve regional and global decarbonization goals.

Supplying half of our future projected electricity demands requires research, design, and development of wind power plants at scales and in locations where we have little experience. Offshore wind plants will need to access areas with deeper water and rely on floating foundations. Observations of the offshore wind resource and its dynamic environment remain quite sparse. Wind plants in close proximity to others offshore, as well as on land in flat, hilly, and mountainous terrain, will need to be optimized for their interactions, which are also poorly characterized. The new turbines will need to be larger, longer, lighter, and collectively controlled to both optimize plant productivity in lower-resource areas and meet the electrical system operational demands. Wind power plants will be expected to serve as the backbone of the electricity system, forming the grid and providing essential grid reliability services, often hybrid with storage and other renewable energy systems, to enable more comprehensive services. Success to date has been achieved by engineering around gaps in our knowledge, with solutions often driven by experience as much as by fundamental understanding. Unfortunately, this approach can no longer provide the innovation demanded to support the systems of the future. There is both a tremendous potential for wind energy and a massive knowledge gap between where we are and where we need to be. The good news is that the community has developed a plan to address the scientific and technological challenges, which are surmountable, with appropriate investments.

With the support and guidance of the EAWE Publications Committee, draft articles are being submitted to WES throughout 2022. This collection of articles reviews the broad sweep of wind energy research needs and proposes actions that will enable wind to be a foundation for the energy system of the future. The charter for the authors was not to suggest particular innovative solutions or to tout specific technology advances, but to review the literature and to articulate the most critical needs, with the intent to synthesize and clarify. From this assessment of the current status of the field, recommendations for critical actions emerge. These articles are not specifically intended to be road maps but to provide the basis for road maps developed by agencies, governments, or other groups as they seek to prioritize resource allocations.

Shifting the global energy system away from carbon-based sources will require an investment of trillions of euros in wind energy installations. This shift cannot be expected to succeed at current research and development levels of investment. By articulating the magnitude of the gaps, required resources, and roadblocks, these articles make a case for increased resources to respond effectively to the challenge of deploying wind power everywhere.

In total, 10 articles will be submitted this year; each expresses a portion of the total story and recommends needed action to fill critical gaps. To access the articles in this series, visit https://eawe.eu/organisation/committees/publications-committee/ (last access: 7 December 2022).

Individual articles describe the research challenges in each area.