Old, discarded wind turbine blades don’t biodegrade. They do, however, float if sealed. Finnish startup Reverlast is capitalizing on that fact, by taking end-of-use blades and converting them into stylish floating docks.
Although wind turbines are a prominent symbol of the green energy movement, their giant mostly-fiberglass blades typically have to be replaced every 20 to 30 years. Recycling them is a challenge, as it’s quite difficult to break fiberglass down into its glass-fiber and epoxy resin components.
As a result, decommissioned blades are most often crushed and burned in kilns as part of the pyroprocessing stage of cement production. Unfortunately, the crushing process is energy-intensive, and the burning process generates greenhouse gases. More infamously, the blades are also sometimes simply buried intact in landfills – out of sight, out of mind.
That’s where Reverlast comes in.
Founded last August by alumni of Aalto University’s schools of technology, art and commerce, the company currently takes old turbine blades, cuts them up into shorter sections, then fills those sections with expanded polystyrene foam. Plans call for the sections to instead be sealed with fiberglass caps at the exposed ends, eliminating the need for the foam filling.
Aalto University
The end product is sleek, stable pontoons that are used as floatation for the company’s line of floating docks. Those pontoons are quite durable, as their fiberglass shells are up to 6 cm thick (2.4 in), depending on what part of the blade they’re cut from. For reference, the fiberglass used in sailboat hulls is typically only about 1 cm thick (0.4 in).
In an initial demonstration of the product, Reverlast is building a floating platform for Aalto University’s new community sauna. The structure utilizes pontoons cut from the midsection of four turbine blades, each polystyrene-filled pontoon tipping the scales at over 300 kg (661 lb) – the planned non-foam-filled pontoons should be considerably lighter.
Reverlast
“We repurpose turbine blades to build floating docks and pontoon structures,” says company co-founder Ossi Heiskala. “This reduces the need for traditional pontoon materials like concrete and polyethylene plastic, making the solution even more environmentally friendly. Our prototype dock prevents roughly 2.6 tons [2.4 tonnes] of carbon dioxide emissions, and the larger and more numerous the docks we build, the greater the impact.”
Of course, this isn’t the only proposed use for decommissioned turbine blades we’ve heard of in recent years. Other examples have included utilizing them in asphalt, stand-up paddle boards … and even gummy bears.
Sources: Aalto University, Reverlast