3 sustainable materials powering the renewable energy transition

As the energy transition gains momentum, attention is turning from renewable energy sources to the materials they are made from as a way to bolster decarbonization efforts.

Incorporating sustainable materials into clean energy solutions helps reduce their environmental impact and could potentially improve their output or efficiency.

Renewable energy deployment has grown exponentially, but innovation in next-generation energy technologies is necessary, according to the World Economic Forum’s Fostering Effective Energy Transition 2023 report.

Here are three energy transition innovations built using sustainable materials.

Wind-powered turbines are nothing new. In many countries they dot the landscape or form part of large offshore wind farms at sea.

But engineers at a start-up in Sweden have constructed the world’s tallest wooden wind turbine, replacing the steel construction used in traditional designs. Its 2-megawatt generator has just begun supplying clean electricity to Sweden’s grid, with capacity to supply around 400 homes.

The turbine’s tower stands 105 metres high – 150 metres to the tip of the highest blade – and is constructed using 144 layers of laminated veneer lumber (LVL), which is glued and compressed to form curved sections. The result is a thick, strong and flexible column.

As wood is lighter than steel, taller turbines can be constructed using fewer materials, the concept’s co-designed David Olivegren told the BBC. Even taller towers are planned for the future.

While generating wind power doesn’t create emissions, producing the steel used to make traditional turbines is carbon intensive.

However, substituting steel for wood is carbon negative, as no carbon is emitted during manufacture of the turbine tower and the wood acts like a store for the CO2 trapped by nature when the trees were alive.

The science behind wind farms indicates that the bigger the blades, the more electricity each turn generates, giving rise to an industry trend for larger and larger designs.

As the race for size gains pace, transporting supersized steel turbine towers and blades to both land-based and offshore sites has become increasingly challenging, requiring specially built vehicles to transport them and reinforced ports and loading infrastructure to support additional weight.

The wooden turbine’s construction is modular, so it can overcome many of these challenges.

Renewables like wind and solar power are generated on a use-it-or-lose-it basis, unless any surplus energy can be stored for later use when needed.

Storage mediums like batteries are one solution, but these often require critical minerals that are at risk of shortage and could pose an environmental impact if not well managed.

However, Vatajankoski power plant in Finland is home to the world’s first commercial-scale sand battery, a solution that is simple, abundant, sustainable – the planet has plenty of sand – and cheap.

The facility consists of 100 tonnes of low-grade sand unsuitable for construction, which is surrounded by thick insulation to retain heat. Renewable energy from wind turbines and solar installations in Finland power a resistance heater that heats the air inside the battery, which is circulated through heat exchange pipes by a fan.

At a constant temperature of up to 600 centigrade, the sand battery has capacity to store 8 megawatts of thermal energy. When demand increases, the battery discharges about 200 kilowatts of power through heat exchange pipes, which is enough to provide heating and hot water to around 100 homes and a public swimming pool, supplemented by grid power.

The battery is recharged overnight when electricity demand, and therefore prices, are lower. As the system is fully automated, running costs are minimal.

While sand stores between 5 to 10 times less energy (per unit volume) than traditional chemical batteries, no chemical reaction takes place in sand batteries so they don’t degrade and are not flammable. Sand also has a much lower environmental impact than lithium-ion batteries, making it a sustainable way to store energy until it is needed, helping overcome the intermittency challenges associated with some renewable energy sources.

Energy storage is a critical component of the switch to cleaner energy. By 2028, renewable energy sources are predicted to account for more than 42% of global electricity generation, says the International Energy Agency, with wind and solar together accounting for 25%.

A leading global tyre manufacturer is developing a new type of ‘self-generating’ tyre for electric vehicles, capable of adapting to different road or weather conditions, or changing profile to suit individual drivers’ journey preferences.

The tyre is linked to a refillable container housed in the vehicle’s wheel hub that contains biodegradable tyre tread compound, a biological substance strengthened with fibres to enhance its durability.

A capsule propels the compound to replace worn tread on the tyre surface, or to change the tyre’s profile over time to suit different driving conditions, all without the hassle of having to remove the wheel and replace the tyre.

The result is a convenient, highly durable and biodegradable solution that eliminates the problem of what to do with all those discarded, worn-out car tyres.

These are just a few ways that more sustainable materials have been incorporated into clean energy solutions to help efforts to decarbonize.