Wind turbine blades to get second life as long duration energy storage

A joint venture between Italian renewables giant Enel Green Power and Swiss tech group Energy Vault is seeking to use recycled wind turbine blades as a key ingredient for an innovative, long-duration energy storage system.

In a statement this week, Enel Green Power says the two companies aim to integrate gravity energy storage technology with the recycling of end-of life wind farm materials, “applying a circular economy across the entire wind power value chain.”

Energy Vault is behind a kinetic energy based, long-duration energy storage solution that is inspired by pumped hydro, but uses blocks of solid material instead of water.

The blocks, weighing around 35 tonnes each, are lifted to store electricity and lowered when it is needed again, using gravity to generate the power as they descend.

The solution, which is controlled by proprietary software and “computer vision,” has the advantage of a much lower cost than pumped hydro, according to Energy Vault, and greater ability to be replicated in any geographical context and with greater storage efficiency.

Compared to batteries, Energy Vault says its technology has further advantages of not being exposed to storage medium degradation or risk of fire, while offering a long lifespan of 30-35 years and easy dismantling and decommissioning.

At this point, the company has a 5MW commercial demonstration unit of the technology up and running in Ticino, in southern Switzerland.

For its part, Enel Green Power has been looking for recycling solutions for end-of-life wind farm parts, including the “shredding” of obsolete blades to use as a raw material for the manufacture of products in other sectors, such as construction.

Together, the two companies have found that Energy Vault’s recently announced upgraded “EVx” product storage platform could be “ideal” for the use of reclaimed wind blade fibres.

“The use of this material gives the blocks greater stability and robustness, increasing their durability and further lowering costs,” said Enel Green Power’s head of innovation Irene Fastelli, in a statement.

“The partnership with Energy Vault involves feasibility studies for integrating the composite material from Enel Green Power’s decommissioned turbine blades into the blocks used by the energy storage system.

“All of this occurs as part of a circular process, which includes the decommissioning of the wind plant, the treatment of the composite material at a shredding plant, its processing and reintegration into the energy storage system, Fastelli said.

“Our technology-enabled solutions were created for this exact purpose – to allow clean energy companies to be 100% sustainable, and to overcome the final hurdle in the journey towards a fully circular economic approach,” said Robert Piconi, Co-Founder and CEO of Energy Vault.

“Thanks to this strategic partnership with Enel, we join forces and accelerate the transition towards renewable energy.”