Wind energy is key to fulfilling the objectives of the Paris Agreements, but today’s wind turbines exhibit significant limitations. In onshore applications wind turbines face spatial constraints and public acceptance issues, while deeper waters offshore are heavily constraining deployment possibilities. The “MegaAWE” consortium of 26 partners, has formed to mature an alternative which addresses these issues: utility-scale Airborne Wind Energy Systems (AWES).

AWES can unlock new frontiers for wind energy harvesting, such as floating offshore and rural onshore locations. This is possible because energy is harvested efficiently at higher altitudes where wind is strong for a greater proportion of the year. By using an aircraft to more efficiently reach these altitudes, the reliance on materially intensive structures is reduced dramatically. This yields cascading benefits including a lower carbon footprint and reduced visual impact for neighboring populations. Studies have shown that AWES can cut the carbon footprint of wind energy in half and reduce the amount of used material per MWh by 80%.

The project

The MegaAWE project aims to bring utility-scale AWE systems closer to commercial reality and to prepare the supply chain in North West Europe (NWE) for a utility-scale prototype demonstration. The partnership covers a wide range of stakeholders to support knowledge transfer and to strengthen innovation capability in the region, including both users and technology providers. This network will facilitate discussion on AWE solutions, provide opportunity for technology demonstration, and pair needs with the technological capabilities available from Europe’s SMEs and established industry.

The total budget of MegaAWE is €12.3M, of which €6.8M have been granted by the European Regional Development Fund Interreg North-West Europe. “This is a big achievement for us, our partners in the consortium and the entire sector. With the Interreg funding we will lay the ground to scale this technology by about a factor 10 in terms of power output, and demonstrate it in the region”, says Stefan Wilhelm, Product Assurance Officer at Ampyx Power.

The consortium is led by Mayo County Council, Ireland and Ampyx Power is the main technological solution provider. User partner RWE Renewables will develop an AWES test hub in Mayo County. The regions of South Holland, Nordrhein-Westfalen, Brittany and the French Mediterranean region Occitanie will contribute with supply chain, demonstration sites and deployment opportunities. Innovation centers from Ireland, the UK, The Netherlands and Germany will support regions with evaluation of the solutions from a technical and public perception point of view. Technology partners SABCA, Parkburn Precision Handling Systems, Siemens SISW, Infracore, Stellar Space Industries will support up-scaling of the Ampyx Power solution to megawatt scale and the development of affordable series production processes. Sector organization Airborne Wind Europe will ensure knowledge-sharing between the MegaAWE consortium and the wider AWE community, and work on the necessary financial support instruments for AWES development within Europe.

The key challenges in developing megawatt scale airborne wind energy have been identified and are actively being addressed with technical partners in the MegaAWE consortium. Firstly, there is a need for a safe and fully automatic endurance demonstration. This will be done with our 150-kW commercial demonstrator AP3 on the AWES test center in County Mayo that is being developed by RWE Renewables. Other challenges include the development of the aircraft’s composite structure for cost-effectiveness and mass reduction, characterisation and improvement of tether handling and wear, and the development of cost-effective drivetrain and energy storage solutions.

Key Technologies that are developed in the project:

1. The AP-3 airframe design and manufacturing followed traditional aviation guidelines, and this proved to be both tedious and costly. With partners SABCA and Siemens, Ampyx Power will simplify the design and production methods, bring down the weight by 20%, and reduce the cost by an order of magnitude.
2. The tether is made from Ultra High Molecular Weight Polyethylene, which is strong, lightweight, and smooth for handling. However, the tether wears down over time and must be replaced at regular intervals. This maintenance represents a significant fraction of the Levelized Cost of Energy (LCoE), a common indicator used to assess the attractiveness of different power generation technologies. Thus far, little research has been conducted on the mechanisms and indicators of tether wear for heavy duty tethers operating at high speed. The tether handling design, including winch and sheave configuration, will be dictated by the need to minimize such wear mechanisms. This problem is being addressed in cooperation with Parkburn as part of an initiative to assess tether handling and lifetime characteristics at full scale.
3. The third key technology is the megawatt-scale drivetrain. In order to provide constant power output, a fast cycling energy storage solution is required. This is because power is generated in short durations typically lasting only 1 minute or less. Between power generation cycles the system must reel the tether in under low tension and at very high speed. The trade-off between electrical or hydraulic drivetrain technologies depends on the scale of the system. To better understand this relationship a hydraulic solution will be designed, built and demonstrated at megawatt scale.

Aside from technological challenges, other significant considerations relate to engagement with future users, regions, certification authorities and the general public in order to understand their needs and requirements. This input will inform the early stages of technology development as well as a detailed plan to develop and demonstrate a utility-scale commercial AWES as a major step toward expansion of AWES applications in North-West Europe and beyond.