07 April 2023
By Will Lockett
 

Wooden Wind Turbines Are A Game Changer

prototype wooden wind turbine — Modvion

Wind power is an incredible source of energy, with some of the lowest carbon emissions of any energy source and a far more reliable power output than solar, particularly in windy countries. With these credentials, wind power is already set to drastically reduce humanity’s climate impact over the coming decades. But this planet-saving technology has two huge problems. Firstly, it makes sense to build taller wind turbine towers, as there is more powerful and more reliable wind higher up, but it costs too much to build steel towers that tall, making this approach unviable. Secondly, the majority of a wind farm’s construction-related carbon emissions come from building these giant steel towers. So if wind power is to further reduce its carbon footprint and become more powerful and reliable, it needs a new way of reaching into the sky. Luckily, this is where Modvion and their wooden turbine towers come in. But will they be enough to turn wind power into the ultimate renewable energy source?

Modvion’s towers aren’t just a solid lump of wood, as that would be incredibly wasteful and not particularly strong. Instead, like a steel turbine, they are hollow inside with regular bracing. This design mimics bamboo, making the tower highly durable and lightweight. But instead of steel, Modvion uses laminated wood. Boat builders have used this type of wood to build super-light, high-performance boats for decades, as it is resilient, lightweight, durable, and plentiful. Furthermore, laminated wood is far less carbon-intensive than steel and much cheaper.

Now, your gut might be telling you that a turbine tower built from wood would inherently be inferior to our current steel ones. You might even picture them buckling in a strong wind. But you’d be wrong. Let me explain.

Laminated wood is made of thin layers laid on top of each other, with their grains positioned in varying directions, which are then either glued or resined together. In this way, laminated wood is very similar to carbon fibre, as the wood itself is a form of carbon filament (lignin), and the layers of wood stuck together mimic the weave and resin of carbon fibre. This makes it both extremely strong and very light. In fact, its weight-to-strength ratio is much better than that of steel.

When building tall structures, your weight-to-strength ratio is essential. Otherwise, the weight of your structure increases too much as you build taller, meaning you need to use extra bracing, making it both more expensive and heavier, which can restrict how high you can build. While laminated wood is about as strong as steel, it is far lighter, making it better suited to building tall structures. In other words, it is easier and cheaper to build taller towers from laminated wood, as it uses far less material while being just as strong.

This is why Modvion’s towers can be used to either make much cheaper or much taller turbine towers. In fact, using Modvion’s technology, the upper limit of how tall you can build towers is 1,500 m, about ten times higher than current towers! Now, that height isn’t commercially viable, but towers 50% to 100% taller are well within their capabilities. And don’t forget, taller turbine towers mean the turbine can access more powerful and reliable winds, allowing the turbine itself to have a higher output, which overall lowers the cost of its energy. So both options actually lead to reduced costs while having a tower that is just as strong.

However, Modvion’s towers go far beyond simple economics. You see, their towers are actually carbon-negative!

Trees build their giant, carbon-rich bodies from the carbon dioxide they have captured from the air. Like all plants, they use photosynthesis to combine carbon dioxide and water and turn it into sugars like glucose and oxygen. But trees tie these glucose molecules together into a long, chemically stable chain known as lignin, which they then use to create wood.

Now, the amount of carbon dioxide Modvion emits during the production of their wooden towers is less than the carbon stored within them. As such, they are overall carbon-neutral. In contrast, steel is incredibly carbon-intensive, as it has to be mined, refined, shipped, and manufactured at high temperatures. This is why the steel tower is by far the most carbon-intensive part of a wind turbine and is a significant contributor to its lifetime emissions.

So by switching to a Modvion wooden tower, a wind turbine can become far more eco-friendly. In fact, a wooden tower reduces emissions by 90 percent when compared to a conventional steel tower of the same height and load! What’s more, Modvion sources its wood from sustainable locations where e-growth exceeds logging, ensuring they aren’t powering deforestation and keeping their eco-credentials squeaky clean.

Modvion can now make wind power cheaper, more powerful, and a lot more eco-friendly, and it seems the industry has started to take notice.

Modvion and Sweden’s RWE have joined forces to supply the first wooden towers to RWE’s future onshore wind farms. Lars Borisson, Head of Onshore Origination & Development Nordics at RWE Renewables, stated, “We see that modular towers in laminated wood have significant market potential and can contribute to lowering the cost of new renewable electricity production by replacing steel and concrete with environmentally friendly and climate-smart wood. RWE will be assessing Modvion’s wooden tower for potential use in future wind farms.”

If this partnership is successful, I’m sure Modvion will be swamped with demand from the wind turbine industry. While their technology is simple, it solves some of the core problems of wind power while offering astonishing eco-credentials. So yes, I think Modvion has the potential to turn wind power into the ultimate renewable energy, and I can’t wait to see where they go from here.