Micro Wind
The turbine on every rooftop is one of the most romantic images in clean energy, and one of the most reliably defeated by physics. Small wind is genuinely good in the right place and almost nowhere else. Even Project Drawdown files it under “keep watching.”
The effect compounds within years. Put it in place and it keeps working.
Project Drawdown classifies this as Keep Watching.
Origins
Catching the wind is ancient. Persian vertical windmills were grinding grain by the ninth century; the European post mill and the great Dutch drainage mills reshaped whole landscapes long before anyone spoke of energy in watts.
Small wind’s truest ancestor is American. Daniel Halladay’s self-regulating farm windmill of 1854 — the iconic multi-bladed steel fan on a lattice tower — did not make electricity. It pumped water, and by doing so it made the dry interior of a continent habitable. Perhaps half a million of them turned above the plains, watering cattle and filling the tanks that let the railroads cross the arid West. It is one of the most quietly consequential machines in American history.
Electricity came later, with the Jacobs Wind “light plants” of the 1920s and 1930s, which brought power to farms that the grid had not yet reached. They worked. And then they were killed — not by a better turbine, but by the Rural Electrification Administration of 1935, which ran grid lines to those same farms and offered power that was cheaper and never becalmed. Small wind’s first death was simply the grid arriving.
Its modern revival came with the oil shocks of the 1970s and the environmental awakening that followed, then with net metering and feed-in tariffs. But it has always lived in the shadow of two larger things: the utility-scale turbine that does its job at a hundredth the cost, and, more recently, the solar panel that does distributed generation with no moving parts at all.
What it actually is
Everything about small wind is governed by a single, merciless relationship: the power in wind rises with the cube of its speed. Double the wind and you get eight times the power. Halve it and you get one eighth. There is no arguing with this; it is arithmetic.
At utility scale, the cube is a blessing. Site a machine in a steady twenty-mile-an-hour corridor, lift it two hundred feet into smooth fast air on a rotor the width of a football field, and the numbers are extraordinary. That is why big wind now produces some of the cheapest electricity ever generated.
At rooftop height, the same cube is a curse. Near buildings and trees the air is slow, gusty, and constantly changing direction — turbulent, in the exact way a turbine most hates. A machine rated at five kilowatts reaches that rating only in a wind of roughly twenty-five miles an hour; at fifteen, it may make a single kilowatt. The rating on the box describes a wind that rarely blows where people actually live.
And height is not a detail, it is the whole game. Because of the cube, a twenty percent increase in wind speed yields about seventy percent more power — which is why viable small wind needs an eighty- to a-hundred-and-twenty-foot tower to reach cleaner, faster air. Which means small wind was never really a rooftop technology at all. It is a tall-tower-on-an-open-acre technology, wearing a rooftop costume that suits it badly.
None of this makes it a bad machine. It makes it a machine with a narrow envelope, sold as though the envelope were wide.
The numbers
Drawdown’s own verdict. Project Drawdown does not count micro wind among its global climate solutions. It classifies the technology as “keep watching” — promising, but below their threshold to matter at planetary scale, because the total suitable market is limited and the economics are too variable.
The cost gap. Small wind runs roughly six to twelve dollars per watt installed, against about two-and-a-half to four for rooftop solar. Paybacks are commonly fifteen to twenty-five years for wind versus six to ten for solar — and on a poor site the payback can exceed the turbine’s own twenty-to-twenty-five-year lifespan, meaning it never pays back at all.
The energy debt. Per unit of energy delivered, the emissions from manufacturing and installing a small turbine can be several times higher than for a large utility-scale one. On a weak site, the machine may never generate enough clean energy to repay the energy that built it.
The upkeep. Moving parts in the weather need service: five hundred to two thousand dollars a year is typical. Solar, by contrast, mostly just sits there.
Where the arithmetic flips. Give it a measured twelve-mile-an-hour average, an acre or more, a tall tower, and a rural site, and small wind can supply half to four-fifths of a home’s electricity with a payback under ten years. Those conditions are real. They are just uncommon, and almost never present on a suburban roof.
Why it matters
We are fond of small wind, and we want to be honest about the fondness, because the fondness is the trap.
There is a deep pull to a turbine turning on your own land. It is visible, kinetic, and unmistakably yours. Solar just sits there in silence; wind moves, and moving things feel alive, feel like power in a way a dark panel never will. That romance has put a great many turbines onto sites that could never carry them.
The failure here is rarely fraud. It is a rated number — five kilowatts! — describing a wind that does not blow at that address, meeting a hopeful homeowner who reads the rating as a promise. The machine is honest about what it can do in the wind it was tested in. Nobody checked whether that wind was ever coming.
And the lesson generalises, the way these lessons do: a clean technology in the wrong place is not clean. A turbine that never repays its own energy debt is worse for the climate than the solar array that would have gone up in its place. The rooftop with the disappointing turbine is usually a rooftop that solar would have served well.
There is a quieter point too, about credibility. It does the cause no favours to oversell. The trust we spend overpromising on a suburban turbine is trust we no longer have later, for the things that genuinely scale. Better to say plainly where small wind wins and where it does not.
Because where the wind is truly there — the open plain, the exposed ridge, the island croft, the off-grid cabin miles from the nearest line — small wind is a genuinely fine answer, and sometimes the only one. We would simply rather it were sold as exactly that.
What it actually takes
Measure before you buy. Twelve months of real anemometer data at hub height. Wind atlases alone carry twenty to thirty percent error — enough to turn a good site into a bad investment or the reverse. Almost nobody measures. Everybody should.
Be honest about height. If the site cannot take an eighty-foot-plus tower, it almost certainly cannot carry wind. That sentence disqualifies most suburban lots, and saying so is a kindness.
Pair it with solar, don’t pit it against solar. Wind tends to peak in winter and at night; solar peaks in summer at midday. On a genuine wind site the two together cover far more of the year than either alone.
Off-grid and rural first. The strongest case is the site with no line to the pole, where the honest alternative is a diesel generator. There, a turbine on a tall tower is not a lifestyle statement; it is infrastructure.
Stop bolting turbines to suburban roofs. This is where most of the harm is done: small machines in turbulent, slow, obstructed air, guaranteed to underperform, quietly discrediting the entire category for everyone else.
Where it matters most
The Great Plains and High Plains are small wind’s honest heartland — the same open, ceaselessly moving air that turned half a million farm windmills a century ago. Here the technology tells the truth about itself.
The Scottish Highlands and the exposed northern coasts are among the windiest inhabited places on earth. Off-grid crofts and island communities, far from any mainland line, are a genuine home for a well-sited turbine.
Patagonia — where the wind roars almost without pause across the bottom of the world, and much of the land lies far from any grid — is about as close to small wind’s natural country as the planet offers.
The Great Basin and the interior West hold scattered off-grid homesteads where a tall tower on an open acre genuinely beats hauling diesel.
The Pacific Northwest and the Texas Hill Country are the cautionary middle: ridgelines and gaps that funnel real wind, sitting right beside valleys that kill it — which is precisely why measurement, not a map and not a brochure, has to make the decision.
How to tell it’s being done well
What is the measured average wind speed at hub height? Below roughly ten to twelve miles an hour, stop. This is the entire question, and a twelve-month measurement is the only honest way to answer it.
Can the site take a tall tower, with proper setbacks? If the plan is a mount bolted to a house in a subdivision, the answer is almost always no, whatever the brochure implies.
What is the payback on measured output, not the rated number? If it exceeds the turbine’s own lifetime, this is not a climate solution. It is a lawn ornament that occasionally makes electricity.
Would solar have gone here instead? If yes, and the site is not exceptionally windy, solar almost always wins on cost, simplicity, and reliability.
Off-grid or grid-tied? Off-grid and rural is the strong, defensible case. Suburban and grid-tied is the weak one, and the source of most of the disappointment.
Where this matters most
Who is working on this
We are researching which organizations in our directory of 8,493 actively work on this solution, and we only list an organization once we have verified it. That research is ongoing. In the meantime, search the directory yourself:
Questions
Can I put a wind turbine on my roof?
You can, and you almost certainly should not. The air next to a building is slow and turbulent, the two conditions a turbine most dislikes, and because power rises with the cube of wind speed, a small drop in speed is a large drop in output. Viable small wind needs a tall tower on open ground, not a rooftop mount.
Is small wind cheaper than solar?
No. It typically costs two to four times more per watt installed, with fifteen-to-twenty-five-year paybacks against six to ten for solar, plus real annual maintenance because of the moving parts. For most homes, solar is the better distributed-generation choice.
Why does Project Drawdown say keep watching instead of endorsing it?
Because even across all the world's suitable sites, micro wind cannot reach the scale to matter globally, and its economics swing wildly from site to site. It is promising in the right place and marginal almost everywhere else, so Drawdown watches it rather than counting it as a global solution.
When does small wind actually make sense?
When you have a measured average wind of twelve miles an hour or more, at least an acre, room for an eighty-foot-plus tower, a rural setting, and ideally either an off-grid site or a solar array to pair with. Meet those and it can be excellent. Miss them and it disappoints.
Does it really emit more than big wind?
Per unit of energy, the footprint of building and installing a small turbine can be several times that of a utility-scale machine, and on a poor site it may never generate enough to repay that energy debt. Scale matters, and small wind sacrifices it.
Sources
- Project Drawdown - Deploy Micro Wind Turbines (classified Keep Watching) Framework and classification. Cited, not reproduced.
- US Department of Energy - Small Wind Guidebook (WINDExchange)
- IRENA - Renewable Power Generation Costs
- US DOE / PNNL - Distributed Wind Market Report
The solution taxonomy follows the framework popularised by Project Drawdown. The analysis above is our own; for their carbon modeling and rankings, visit them directly.