Bill Gates backs novel device promising wind energy at 1/3 the cost

Bill Gates backs novel device promising wind energy at 1/3 the cost
An oval-shaped track supports a series of vertical wings, which harvest wind energy to pull themselves around in a loop
An oval-shaped track supports a series of vertical wings, which harvest wind energy to pull themselves around in a loop
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An oval-shaped track supports a series of vertical wings, which harvest wind energy to pull themselves around in a loop
An oval-shaped track supports a series of vertical wings, which harvest wind energy to pull themselves around in a loop
An early small-scale Airloom prototype is already operating
An early small-scale Airloom prototype is already operating

It looks nothing like a typical "fan on a stick" wind turbine, but this oval track with evenly spaced wing blades could be an enormously disruptive addition to the renewable energy mix, since it slashes the cost of wind power to unprecedented lows.

Wyoming's Airloom Energy has come out of stealth mode with a new CEO fresh out of Google[x], US$4 million in seed funding, led by Bill Gates's Breakthrough Energy Ventures fund, and a radically different technical approach that it says fundamentally upends the financial equation for wind farms.

Wind turbines are getting absolutely enormous, with some new designs standing taller than the Eiffel tower, as some of the largest moving machines in history . And they'll continue getting bigger, because the bigger they get, the greater the energy incentive becomes to make the blades even longer.

But their sheer size increases cost at every step; the materials, manufacturing, transport, logistics, construction and maintenance budgets all take a severe hit when you're dealing with long blades, tall tower structures, and massive generators that have to live at the top of them and support the blades.

Airloom's approach makes everything much smaller and much closer to the ground. A 2.5-MW Airloom setup would use a number of 25-m (82-ft) poles to suspend an oval-shaped track, into which a series of 10-m (33-ft) wing blades are set, joined by a cable.

Like sailboats, which can harvest motion energy from wind in any direction except dead-ahead or straight behind, these blades harvest wind energy as they travel around the track, which is oriented such that its long sides are angled for maximum wind capture and its short ends are spaces where the blades can change direction as the rest of the blades haul them around.

Power takeoffs harvest linear motion from the cable to run generators. Where a regular wind turbine gets maximum torque from the tips of its blades and very little from the bits closest to the hub, the full length of each of the Airloom system's blades will contribute to hauling the whole loop around, with effectively a short break twice per revolution as they turn around at the ends.

Thus, a 2.5-MW Airloom track will fit on a single truck, it won't require enormous turbine tower cranes (or indeed the remarkable climbing cranes that are starting to pop up), the parts can be built in relatively small factories, from non-specialist materials, and every part of installing and maintaining them becomes easier, cheaper and safer.

Compared with a regular turbine, for example this 2.5-MW-rated GE unit – a 100-m-diameter (328-ft) fan supported by a hub held 85 m (279 ft) high on a tubular steel tower – Airloom says a wing track will be less than 10% of the cost, at somewhere under US$225,000. Add in the land requirements and whatnot, and a full wind farm setup promises to be less than 25% of the capital cost, at less than $6 million for a 20-MW wind farm.

And at the brass-tacks level, Airloom claims its design will bring the Levelized Cost of Energy (LCoE) of wind energy down to about one third of what it costs today per kilowatt-hour, somewhere around 1.3 cents per kilowatt hour – making one of the cheapest forms of renewable energy much, much cheaper.

An early small-scale Airloom prototype is already operating
An early small-scale Airloom prototype is already operating

It also promises to be far less visually intrusive than tall wind turbine towers, potentially making it relevant to a wider range of sites and reducing NIMBY opposition. It's capable of scaling horizontally, to the point where the tracks could run for miles, and the height of the system can also be altered to make maximal use of a given site.

“For decades, the wind industry has lowered the cost of energy production by scaling ever larger turbines," said Carmichael Roberts of Breakthrough Energy Ventures, in a press release. "Although this has been extremely successful in driving down overall costs, the approach now faces challenges in terms of both siting and cost of materials. Airloom’s unique approach can solve both these problems, opening new market opportunities for wind energy that will further drive down costs. We look forward to [new CEO] Neal [Rickner]'s leadership in bringing this revolutionary technology into the market.”

With smallish-scale prototypes already up and running, Airloom will use its seed funding to prove the technology with a 50-kW test device, and will move to commercialize and scale it from there.

We'll be interested to learn what kind of capacity factor these wingtrack setups will achieve in a wind farm setting, as compared to the average 35% capacity factor of on-shore wind turbines in the USA. You'd think that being lower to the ground, the Airloom system might miss out on the higher wind speeds further up.

Airloom also says the idea will work offshore, where the bulk of the best wind resources can be found. That's interesting; presumably it'll simply require longer poles, anchored in the sea floor.

Still, energy is primarily a cost game, and if this machine can pump out energy at a third the price of a tall tower, capacity factor won't matter, and land resources will become available. We're fascinated to learn how this idea progresses, although we expect progress to be painfully slow. And while it's hardly a shining example of a source, we were interested to chance upon this Glassdoor review, in which an anonymous and unsuccessful job interview candidate reports Airloom has been having "many issues" with their first prototype, which they've been working on for seven years.

Source: Airloom Energy via the excellent Recharge News

Guy Wind
Complete joke. This rubbish has been tried before. 1980s in California. Late 90s in Spain. Chinese company tried to push a design in the 2000s. Psssst, there's no wind at ground level, at least none you want to use.
I agree with the first comment although the writer indicates this will work better off-shore which puts a huge cost burden to more than 1.3 cents per kilowatt.
Also, the analogy of: Like sailboats, which can harvest motion energy from wind in any direction except dead-ahead or straight behind—-the writer has no conception of how a sail boat works if he/she believes a sail boat doesn’t work with the wind behind it.
Bob Stuart
Every wind and current generator design I see would probably benefit from using guy wires as much as possible to reduce the costs of the foundations and masts.
Is this idea puny and pathetic? At least it is very cheap. Energy output looks minimal, and it doesn't look very appealing. Next!
Being low to the ground means lower wind speed and larger area means problems with wind gusts and turbulence. Maybe they should try putting wings on a ski lift instead of chairs.
They suggest that this could be extended to miles long. I think that would lower efficiency, since wind velocity will probably vary over that distance, so some blades would be travelling at non-optimum speeds, unless each blade has a fairly complex (and thus unreliable) angle adjusting mechanism.

I don't see why this design should be significantly better than the rail-mounted version from many decades ago, which never proved viable. I see more chances for vibration, blades striking the towers, and other such failure modes.

I put this design in the "You've got plenty of money, so prove that it works." category.
He's a computer programmer, or atleast used to be. There has never been any evidence they he's good at judging technologies.
Since all the comments so far are negatory, I'll be perverse and offer a few in favor of the general idea.

First, there ARE places where there are fairly steady wind resources -- pretty much anywhere near the coast for example. It doesn't have to be actually offshore, just unobstructed relative to the oceanic winds. A second place where there are often consistent winds are up the sides of of at least some mountains.

Second, a second advantage is that one could likely install solar electric underneath the track and double dip on the renewable energy produced by any given chunk of real estate. Sure, not for a solar farm surrounded by woods as one often finds them inshore, but in the plains states or up on a south-facing mountain slope, why not?

Third, it costs me personally nothing for them to play with the idea and see if they can make a design that wins the ROI/cost-benefit-analysis game with vertical giant turbines, which are expensive, dangerous, and obvious targets for the NIMBY crowd to be found almost anywhere one want to build them in the US (but not Europe, where they are already in everyone's back yards). NOT being 100+ meters high is sometimes a practical advantage in other ways than just cost.

With that said, I still have some difficulty believing that vertical fins on a track is an optimal design for lowdown energy harvesting from wind. I can think up several alternate designs offhand that could be used to produce raw torque from wind pressure on greater surface areas that would still be "cheap" compared to huge composite-fiber windmill blades atop enormous towers. I await with interest their 50 KW "prototype" -- either they prove their design is good, or that it isn't, and if it isn't, well, Bill Gates can afford the loss on a speculative investment. Or even on ten of them. All it takes is one hit to pay off all the losses and make a ton of money on a real winner. And there is plenty of competition out there for alternate wind-farm designs, several showcased on New Atlas every month, or it seems that way. In the US at least the NIMBY problem probably trumps the technical problems or practical efficiency -- we simply don't seem to want (collectively) giant propellers mounted on giant towers all over the landscape.

Personally, I'm still hoping -- and even expecting -- practical fusion in the next 3-10 years, which will make most of this moot over the next fifty years. But I won't be around to see it.
It has many advantages to be sure, but seems quite a bit more complex with regards to wing angles changing and the cable system and it's pulleys and friction. I guess the beauty of the normal design is it's relative simplicity. It's just a fan on a wheel (I know it's more complex than that, but there's no cables, and the angle of the blades are easy to change centrally)...
Rick O
This seems like it would have far more parasitic losses from the whole cable system. And as others have mentioned, ground level wind is pretty weak. I personally think that offshore tidal power is a better bet for the future. For one, water can exert more force than air. And for another, removing some of that energy before it gets to the coast can help with erosion issues. Then there's the aesthetic aspects of it all. You likely won't ever see most tidal generation systems. Some designs are underwater. Other designs barely have any height to them, so you won't see them unless you're very close.
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