Resolve Composites, Siemens Gamesa partner in Second Wind project

The Second Wind Project, an initiative led by Resolve Composites (Nova Scotia, Canada) and Siemens Gamesa (Zamudio, Spain), has resulted in the successful recycling of a 6-meter spar cap section from a wind turbine blade into a 5-meter custom boat hull using ReceTT, Resolve Composites’ scalable recycling process that supports different types of solvolysis treatment. ReceTT is reported to efficiently separate full-sized composite products.

Founded by boatbuilders in 2023, Resolve Composites has a clear understanding of composite materials and the environmental impact they have at EOL. The company’s research into composites sustainability for the marine industry began with flax fibers, bio-resins and recycled PET foams. Transitioning to bench-scale testing, Resolve next wanted to assess the properties and advantages of novel recyclable resin systems such as thermoplastics, recyclable epoxies and vitrimers.

Through in-house testing of available resin systems, the team created the challenge to construct and deconstruct a boat, and then reconstruct it using those recovered materials. Practical considerations for on-site recycling played a key role in the resin selection process, taking into account factors such as solvent accessibility, the need for specialized equipment, processing temperature ranges and solvent disposal requirements.

After selecting a suitable resin system, Resolve worked with the Composites Research Network (CRN) at the University of British Columbia on comparative mechanical testing of virgin and recycled materials. The scope included tensile, facesheet and flexural testing, while considering the impact of fiber misalignment and sizing removal on specific property losses.
Test results demonstrated the recovered materials maintained sufficient strength for boat manufacturing, having an average property loss of 10%.

By constructing test coupons with recycled material, the team at Resolve gained practical experience, familiarizing themselves with the resin system and its recovery process. This highlighted the logistical challenges of recycling larger composite products, even with all the capabilities of an advanced resin system. The necessity of obtaining high-quality, unshredded feedstock to build a boat led to the company’s next step: developing ReceTT. 

“We developed this method for solvolysis with limited resources, funding, and specialized equipment, reinforcing its accessibility for builders and recyclers across all industry levels,” explains Nick Bigeau, CTO, Resolve Composites.

Scaling ReceTT from bench testing, Resolve experimented with a prototype boat bow section, generating the first data on ReceTT’s efficiency in recycling larger complex geometries. According to the company, results included complete material recovery and an 89% reduction in solvent use
compared to using an immersion tank for a component of the same size and geometry.

Its success indicated ReceTT’s potential for other end markets in the industry, which led to Resolve’s eventual collaboration with Siemens Gamesa and initiation of the Second Wind Project, aiming to validate Resolve’s recycling process and Siemens’ RecyclableBlade application across multiple industries.

From its facility in Denmark, Siemens shipped part of a RecyclableBlade, built using the same recyclable epoxy resin system that Resolve had already been testing with. The project, resulting in the construction of a custom boat hull entirely from recycled fibers, reportedly achieved 100% glass fiber recovery and a 70% reduction in solvent use compared to an immersion tank setup. From a 254-kilogram spar cap section, 170 kilograms of fiberglass was recovered, with both unidirectional and biax fiber architectures remaining fully intact. The longest sheet of recovered fiberglass, just under 6 meters in length, reinforced the effectiveness of Resolve Composites’ ReceTT process in preserving fiberglass integrity while maximizing material recovery. The resin was also cleanly separated from the fibers, though no additional tests were conducted on the recovered resin.

“We focused on the materials we were familiar with for the project,” explains Bigeau. “We are boatbuilders, not chemists, and fiberglass is a material we know very well.” After rinsing and drying, the reclaimed fibers were directly repurposed into a boat hull made entirely from the reclaimed fiberglass and foam core manufactured from recycled PET.

Resolve made the calculated decision to build the boat hull with a thermoset resin with the intention of recycling the prototype. “The idea here is that we would take the opportunity to demonstrate ReceTT as a pre-separation tool for legacy materials and highlight the innovation beyond recyclable resins,” Bigeau says.

Building on the success of the Second Wind Project, Resolve sees significant potential using ReceTT as a first-stage separation of a multistage process: reducing contamination while maintaining fiber length and streamlining the logistics of EOL composite products. In the short term, Resolve is looking to expand its workforce and make ReceTT widely accessible through licensing, establishing it as a fundamental recycling tool within the composites
industry.