Fifty years of large machines, then a small one.

The company is young. The engineering is not. TESUP was established in London in 2018, but the expertise runs back to 1974, through hydroelectric, wind and solar power plants totalling more than 1,000 MW of installed capacity. Utility scale, national scale, the kind of project where a bearing that fails early is a headline rather than a warranty claim.

Most companies in small wind began with a small turbine and worked outward. We spent half a century building the large ones and then brought that discipline down to something that fits on a roof. The scale changed. The standards did not. A 15 kW continuous-rated motor running a household turbine at under 7% of its rating is not an accident of sizing; it is what happens when people who used to specify megawatts are asked to specify a kilowatt.

Decision one: build both halves of the day.

Almost every company in small-scale renewables makes one thing. Wind companies make turbines and point at somebody else’s panel. Panel companies make panels and have never machined a blade. Two industries, one customer, nothing shared. We decided early that a household does not buy a turbine or a panel; it buys a battery that stays charged, and the sun and the wind keep different hours. The sun sets every day, everywhere, without exception. The wind blows hardest in the months the sun is weakest. Build only one half and you have built half a day.

So we build both: the Atlas vertical turbine and the Magnum horizontal turbine on one side, and the semi-flexible Flex panel on the other. It bends to the surface, carries no frame and weighs a fraction of glass, which is why it goes on the roofs, boats, vans and cabins where a rigid panel cannot. Building both halves is also why we can tell a customer which one they actually need, and sometimes that the honest answer is the panel alone, or rigid glass from somebody else.

Decision two: cut it ourselves.

Blade sets are laser-cut in our own building, from 1.2 mm high-strength aluminium, on our own fibre laser. Three profiles come off the same stock on the same bed: 2 to 20 m/s, 4 to 25 m/s, and a six-blade set for 5 to 35 m/s built for exposed coastal sites. Owning the machine means owning the shape. A subcontracted blade is a purchase order and a six-week conversation. A blade on our own bed is a file, a test cut and an afternoon.

When somebody else cuts your parts you pay for four things: the part, their margin, the freight and the wait, and you accept their minimum order, which is how a company ends up carrying four hundred of something on a shelf. Cutting in-house removes the margin, removes the freight, removes the minimum and shortens the wait from weeks to that afternoon. It is not a strategy. It is arithmetic, and it is most of the reason a household turbine from us costs what it does. Manufacturing runs mainly in Slovakia and London, with Turkey as well, and it is the reason we could hold our prices this year while aluminium climbed on the London Metal Exchange.

Decision three: go to every country properly, or not at all.

Global is not a word you earn by shipping abroad. We run 38 retail storefronts in 34 countries plus a rest-of-world store, in 23 languages, each with its own currency, its own tax treatment, its own shipping and its own terms, and every one mirrored again for wholesale. A customer in Osaka, in Rio, in Riyadh and in Trégunc each opens a page written for them and priced for them, and none of them can tell which one we built first.

The shipping side is less romantic and matters more. Since 2018 more than 100,000 orders have left us, from a single blade set to a full turbine, and in the last two and a half years alone they have gone to 75 countries, carried by DHL and UPS to the customer’s door, every carton labelled individually rather than by the pallet so that a single unit can be traced after it has been split off a delivery. Germany, the United Kingdom, the Netherlands and the United States are the largest markets; Turkey, Spain, Italy and Portugal follow. It is the largest household wind turbine installation footprint in the world, and it is why we use the word leader.

The part most companies leave out.

Leading a market is not the same as selling to everyone in it. If your roof sits deep in a dense old city, walled in on four sides, do not buy a turbine from us; buy the panel. If you are inland with no real wind, measure first, then decide. If you have a strong flat roof that will carry the weight, buy rigid glass instead of semi-flexible, because for that job it is the better panel. We can say all of that because we build both halves and because a customer who was told the truth comes back.

It is the same reason we print the air density beside the power curve, publish a 2 m/s start-up speed and then say it is a fair-weather number, and tell you that a photograph of ten finished units is ten finished units and not a promise about your delivery date. Number one is a position you keep by being the company people can check.

Fifty years of engineering. Both halves of the day. Cut in our own building. Sent to 75 countries. That is the whole method.

What comes next.

A machine that runs is an asset. In a year the laser will be an unremarkable thing in the corner of a workshop, covered in swarf, with somebody’s coffee on the control cabinet, and the only trace of it will be a price that did not go up. That is what growth looks like from inside a factory: not a launch, but a bill of materials that gets a little shorter every quarter, and a map of deliveries that gets a little denser.

The mission has not changed since London: to be the world’s leading provider of household clean energy products, at the best possible price, for everyone. We are number one because we started there and kept checking our own claims. We intend to stay that way the same way.

Anyone can sell you a machine.
Only a company that builds both halves can tell you which one you need.
That is how you become number one, and how you stay it.

The founding dates, the 1974 lineage and the 1,000 MW figure are our own company history as published on our corporate page. The storefront, country and language counts are drawn from our own store configuration and can be checked against the store switcher at the top of this page. The order figure is our own company record since 2018 and includes small parts and accessories as well as turbines and panels; the countries-shipped figure is a count from our order records from February 2024 to September 2026. The product ratings, blade ranges and per-unit labelling are our own published product-page specifications. “Number one” and “largest installation footprint” are our own assessment of the household wind turbine market and are not a statement by any independent body. The photographs are our own, taken in our own factories and warehouses.

Where the wind comes from.

Niigata faces north-west, across the Sea of Japan towards the continent. In winter the pressure pattern over Asia sends cold, dry air out of Siberia and across that water. The sea is warmer than the air, so the air fills with moisture; then it meets the mountains that run down the spine of Honshu, is forced upward, and lets go. The Niigata side of those mountains gets the snow. The Tokyo side, a short train ride away, gets the sunshine.

The same pattern is why the wind here is a winter wind. The north-westerly comes in off the sea steadily and hard from December to February, exactly when the days are shortest and a solar panel under half a metre of snow is producing nothing at all. A house in Niigata that wants to make its own electricity through the winter needs something that works in the dark and in the cold. That is the whole case for putting a turbine next to the panels rather than instead of them.

What cold air is worth.

A wind turbine does not make power from wind speed alone. It makes it from the mass of air passing through the rotor, and cold air is heavier. Our published power curve is quoted at the standard air density of 1.225 kg/m³, which is sea level at 15 °C. Niigata’s coast in January sits close to sea level and close to freezing. At 0 °C the same wind carries about 5% more mass than the curve assumes; at −5 °C, about 7% more. A winter gust that would read 960 W on the curve at 12 m/s is worth a little over 1 kW in Niigata air.

That is a small bonus, and we would rather state it precisely than let it grow in the retelling. The larger point is that the wind is there at all, in the months when it is needed, on a coast where the sea keeps the air moving.

What snow does to a machine.

Snow country earns its name. Towns in the Niigata hills routinely measure their winter snow in metres, not centimetres, and the houses are built for it: steep roofs, raised entrances, heated pavements in the town centres. A turbine going there has to be built for it too.

The Atlas is a vertical-axis machine. It does not have to turn to face a wind that swings round the compass in a storm, and it has no tail to be loaded up with ice. Its windings carry Class 200 °C insulation (IEC 60317-13 GR 2), which is a thermal margin the machine will never use in Niigata but which says something about how it is made. The body is aluminium, which does not care about salt from the sea or meltwater from the roof.

The honest caveat is start-up. We publish a 2 m/s start-up speed and it is a fair-weather number. Bearing grease stiffens as it cools, and a still, freezing morning wants more than 2 m/s to break the rotor away from standstill. In Niigata that hardly matters, because a still morning on that coast in January is the exception, but we would rather say it than have an owner discover it.

The mountain takes the snow. The sea sends the wind. A house in between can use both.

The blade set decides the winter.

An Atlas is ordered as a body and a blade set, and the set is the decision that matters. Low-wind blades run from 2 to 20 m/s and must come off before sustained winds above 20 m/s. Moderate-wind blades run 4 to 25 m/s. High-wind blades run 5 to 35 m/s on six blades with a smaller swept area, and that is the set the 4.5 kW peak belongs to.

On a coast that sees winter gales off the sea, the choice is between the blades that flatter the average and the blades that survive the storm. We say the same thing to every customer: choose the set for the worst wind your site sees, not the mean, and let the quiet days take care of themselves.

Rice, snow and a pallet from Europe.

Niigata grows more rice than any other prefecture in Japan, and the terraces in the photograph at the top of this page are the reason it can: the same snow that buries the villages in January melts into the paddies in April. It is a landscape that has always run on what the weather delivers for free. A small turbine on a house there is not a novelty. It is the same idea, with copper in it.

The Atlas and its blades are being packed at our factory in Europe now, each carton labelled individually, and will cross a good deal of sea of their own on the way. When they arrive, the winter wind will already be waiting.

Snow country.
Winter wind.
Atlas, on its way.

The power-curve figures, the 2 m/s start-up speed, the three blade ranges, the 4.5 kW peak system output, the Class 200 °C wire grade (IEC 60317-13 GR 2) and the per-unit labelling are our own published product-page specifications and can be read there. The cold-air figures are the ideal gas law applied at constant pressure: air at 0 °C is about 5.5% denser than at 15 °C, and at −5 °C about 7.5% denser. The description of Niigata’s winter climate, snowfall and rice production is general geographic knowledge. The order is described only by prefecture and product; no customer, address or installation is named or shown. Photographs: Hoshitoge rice terraces, Tokamachi, by Fumihiko Ueno via Wikimedia Commons, CC BY 3.0, cropped; Sasagawa Nagare coast, Yuzawa ski slope and Minamiuonuma morning licensed via Adobe Stock; the Atlas photograph is our own.

Why a ship wants a wind turbine at all.

A ship at anchor still has a hotel load: lighting, navigation electronics, communications, pumps, battery banks that must not go flat. That load is normally carried by a diesel generator idling for hours at a fraction of its rating, which is the least efficient thing a diesel can do. A small wind turbine feeding the battery bank takes hours off the generator, and every hour off the generator is fuel not burned and maintenance not booked.

Under way, the physics get better, not worse. The rotor does not see the true wind; it sees the apparent wind, which is the true wind plus the ship’s own motion. A vessel making 12 knots into a 10-knot headwind puts roughly 22 knots — about 11 m/s — across the rotor. On our published curve that is close to the 960 W we quote at 12 m/s, from a breeze that on land would barely turn a flag.

That is why the same machine we sell for a farmhouse roof ends up on a supply vessel, a patrol boat, a survey ship or a platform tender. The load is the same shape — a battery bank that must stay up — and the wind is more reliable at sea than almost anywhere on land.

What the sea does to a machine.

Salt is the first enemy. Spray reaches every surface, dries, and leaves a conductive crust that finds its way into anything that is not sealed. The second is vibration: a ship’s structure hums at the engine’s frequency for weeks at a time, and a fastener that would hold for twenty years on a chimney will walk loose in a season on a mast. The third is motion itself. The turbine is never level, the wind never comes from one direction for long, and the rotor is asked to start, stop and yaw thousands of times more often than it would on land.

A turbine that goes to sea therefore needs a body that does not corrode, fasteners that do not loosen, a generator that is sealed rather than merely covered, an electrical brake that can hold the rotor in a gale, and a blade set chosen for the worst wind rather than the average one. Our High-Wind blade set runs 5–35 m/s on six blades with a smaller swept area, and that is the set we recommend for anything that lives on the water.

None of that is exotic. It is the ordinary discipline of building for the wrong conditions on purpose, and it is the same discipline that keeps a rooftop machine alive through a coastal winter.

What a fleet asks before it buys.

A homeowner asks what a turbine does. A shipping line, an oil major or a navy asks how you know. Every figure has to arrive attached to a standard, a test or a document with a number on it, and a fleet engineer is not going to take our word for a power curve. The useful thing about being asked is that it forces a supplier to separate what it can evidence from what it merely believes.

Each line is a published specification with a source, not an adjective. That is the only kind of claim a fleet buyer can act on, and the only kind we are willing to make.

The curve, and what it assumes.

The Atlas reaches 4.5 kW peak system output with the High-Wind blade set. The published curve is 290 W at 8 m/s, 960 W at 12 m/s, 1.85 kW at 15 m/s, 2.15 kW at 18 m/s, 3.8 kW at 25 m/s and 4.5 kW at 35 m/s. It is quoted at the standard air density of 1.225 kg/m³, sea level and 15 °C — which, for once, is exactly where a ship lives. A cold sea will beat the figure slightly, because cold air is denser. A tropical one will fall a little short.

The published 2 m/s start-up speed is a fair-weather number. Bearing grease stiffens as it cools, and a still, freezing morning on deck will want more than that to break the rotor away from standstill. We say so because a fleet engineer will find out anyway, and we would rather be the ones who told them.

A rooftop asks a turbine to work. A ship asks it to survive. We build for the second, and sell it to both.

What this page is not.

It is not a statement by anybody but us. The customers named above are our own account of our commercial relationships; none of them has reviewed this page, approved it, or endorsed TESUP, and armed forces do not endorse commercial products as a matter of policy. No vessel, unit, order, installation or contract is named or described here, and we have not reproduced anyone’s seal or insignia.

The ship photographs at the top of this page are licensed stock images. The photograph of warships within the article is a public-domain image released by the US Navy; its appearance does not imply or constitute endorsement by the US Navy, the US government or any armed service. None of the photographs depicts any customer installation, vessel under contract, or personnel of ours.

A homeowner asks what it does.
A fleet asks how you know.
Every figure on this page has a source, and the source is our own product page.

The 15 kW continuous motor rating, the 4.5 kW peak system output, the power-curve figures, the 2 m/s start-up speed, the three blade ranges, the Class 200 °C wire grade (IEC 60317-13 GR 2), the CE and UL certification, the European manufacture and the per-unit labelling are our own published product-page specifications and can be read there. The apparent-wind example is arithmetic: 12 knots of ship speed plus 10 knots of headwind is 22 knots, or about 11.3 m/s. The air-density figures are from the International Standard Atmosphere. The customers named in the opening line are our own account of our commercial relationships and not a statement made by, or on behalf of, those companies or any armed service. Header photographs: licensed via Adobe Stock. Warship photograph within the article: US Navy, public domain (070318-N-HX866-077).

The air thins fast.

Atmospheric pressure at 1,300 m is about 867 hPa — 85.5% of the pressure at sea level. Put that through the ideal gas law at the same temperature and density follows it down: at 15 °C, sea-level air is 1.225 kg/m³ and air at 1,300 m is 1.048 kg/m³. The mountain has taken 14.5% of the mass out of every cubic metre of wind crossing your rotor. Power is linear in density, so it has taken 14.5% of the power with it.

That is a real loss and we are not going to dress it up. In the same wind speed, on the same day, a turbine at 1,300 m has about 85% of the energy available to it that the identical turbine has on a beach. It is also the reason a power curve quoted without an air density is an incomplete number — ours included. Our product page prints the curve and not the density behind it, so everything below takes that curve to be quoted at the standard 1.225 kg/m³. That is an assumption, and you should know we are making it.

Air density against temperature, at sea level and at 1,300 m. Pressure from the International Standard Atmosphere, density from the ideal gas law. Both curves are computed rather than measured, and anyone with a calculator can reproduce them.

Which brings us to the part that is easy to miss, because it pushes the other way.

Cold air is heavy air.

Density is inversely proportional to absolute temperature. Cool a parcel of air from 15 °C to −10 °C at constant pressure and it becomes about 9.5% denser. That has nothing to do with altitude — it happens on the beach as readily as on the ridge. But mountains are where you actually spend your winter at −10 °C, and a high site is cold far more of the year than a low one.

So the two effects work against each other, and at a cold high site the arithmetic is a good deal kinder than the altitude figure alone suggests. At 1,300 m the thin air costs 14.5 points of density. At 0 °C the cold has handed back 4.7 of them; at −10 °C, 8.1 of them; at −15 °C, 9.9. On a properly cold day the mountain has given back more than half of what it took.

To match a sea-level turbine working in 8.00 m/s at 15 °C, the same machine at 1,300 m on a −10 °C day needs 8.18 m/s. A shade over two per cent more wind.

Cold and the machine.

Two things get better and one gets worse. The generator’s N42 neodymium magnets get stronger as they cool: remanence in this material carries a temperature coefficient of roughly −0.12% per kelvin, which means it rises as the temperature falls. A magnet at −10 °C is running about 3.6% stronger than the same magnet at +20 °C. Neodymium’s enemy is heat, not cold.

The windings tell the same story from the other end. We publish a Class 200 °C insulation grade for the wire (IEC 60317-13 GR 2), and at an Atlas’s typical output the motor is running at under 7% of its 15 kW continuous rating — it was never going to be thermally troubled in the first place. Copper resistance falls as copper cools, so a cold generator is a fractionally more efficient generator. Nothing on the electrical side of this machine minds winter.

What does mind winter is everything mechanical. Bearing grease stiffens as it cools, and stiffer grease raises the torque needed to break the rotor away from standstill — the 2 m/s start-up figure we publish for the low-wind blade set is a fair-weather number, and a still, genuinely cold morning will want a little more than that to get moving. Ice matters more. A rime deposit adds mass and changes the section the wind is working against, and an iced rotor is simply not a rotor whose output you should be counting on that day.

The bigger problem.

None of the above is the real difficulty with a mountain site. The real difficulty is that you probably cannot find out how windy it is.

Here is a worked example anyone can repeat. PVGIS is the European Commission’s public solar and wind dataset. We like it, we have used it on this blog before, and for a coastal or lowland site it is a sensible place to begin. Ask it for a typical meteorological year at 45.08 °N, 6.70 °E — an Alpine valley at 1,314 m — and it returns 8,760 hours with a mean wind speed of 0.92 m/s and a maximum, across the whole year, of 3.3 m/s. Not one hour above 4 m/s. Not one.

Read literally, that is a site with no wind worth having. It is not. It is a site the model cannot see. The reanalysis grid underneath these figures is tens of kilometres across and its terrain is smoothed to match, so an Alpine valley, the ridgelines above it and the thermal winds that run up and down it twice a day do not exist at that resolution. The series also fails a check we run before quoting any dataset: in September a single wind-speed value repeats for 10.4% of the month’s hours. That is what interpolation looks like. It is not what weather looks like.

We are saying this about a dataset we rate and continue to use. On flat, open, coastal ground it earns its keep. In complex terrain it is the wrong instrument, and a figure from the wrong instrument is worse than no figure at all, because it arrives looking like knowledge.

What to do.

Measure it. A recording anemometer at hub height through a season costs a small fraction of a turbine and is the only thing that will tell you what your own ridge, valley or roofline does. We have made this argument before about ordinary sites. In the mountains it stops being good practice and becomes the whole job.

Then choose the blade set from what you measured rather than what you hoped. We publish three: low-wind at 2–20 m/s, moderate at 4–25 m/s, and high-wind at 5–35 m/s with six blades and a smaller swept area. A high site is not automatically the high-wind case — a sheltered valley floor can be calmer than a coastline — but a ridge or a col can gust well past what the low-wind set is rated for, and that set has to come off before sustained winds above 20 m/s. Fitting it because the site is usually quiet, then leaving it up through the one storm a year that matters, is how blades get destroyed.

And when you do the yield arithmetic, put the density in. Take our published curve, multiply by the density ratio for your altitude and your typical working temperature, and you have a number roughly 8–15% below the brochure and a great deal closer to what you will actually see on the meter.

The mountain takes about 15% of your air.
A cold night gives more than half of it back.
What neither of them will tell you is how hard the wind blows on your own ridge.

Air pressure at altitude is from the International Standard Atmosphere; density is the ideal gas law for dry air with R = 287.058 J/(kg·K). The reference density of 1.225 kg/m³ is the standard value at sea level and 15 °C. The remanence temperature coefficient quoted for N42 neodymium is a published material property, not a measurement of our own. The 2 m/s start-up speed, the three blade ranges, the Class 200 °C wire grade and the power-curve figures in the left-hand column are our own published product-page specifications; the right-hand column is those figures multiplied by a computed density ratio and nothing else. The PVGIS query was made against the v5.2 typical-meteorological-year endpoint at the coordinates given, and the criticism of it here is a criticism of resolution, not of the dataset’s honesty. No customer, order, address or installation is named, described or shown on this page. The photograph at the top of this page is a licensed stock image of an unrelated Alpine resort, not of any customer’s property.

Slovakia to Germany, without a border stop.

Slovakia and Germany are both EU member states, which means they are inside the same customs union and the same Schengen area. Goods already in free circulation move between them the way they move between two counties: no customs declaration to file, no import duty to pay, no clearance to wait on. The truck does not stop at a barrier because there is no barrier to stop at.

Compare that with a consignment arriving from outside the union, where somebody has to file an entry, a duty may be assessed against a tariff code, and the pallet can sit in a shed until the paperwork clears. None of those steps is dramatic on its own. Together they are the difference between a delivery date you can plan around and one that depends on an office you have never spoken to.

A direction, not a route. We know which two countries this pallet moves between and nothing else is ours to publish.

One thing worth separating out: customs and VAT are not the same question. There is no tax collected at the frontier on an intra-EU movement, but who ultimately accounts for VAT depends on whether the buyer is a business with a valid registration or a private individual, and on which country they are in. That is a question for your own accountant rather than a claim we are going to make on a blog.

The symbols speak no language, on purpose.

Printed on the top cartons are four pictograms: a broken wine glass, a pair of upward arrows, a box held in two hands, and an umbrella. Fragile, this way up, handle with care, keep dry. There is no text with any of them, and that is deliberate — they are the international handling marks, drawn the same way everywhere, so that a person loading a trailer understands them without knowing a word of the language on the box.

It is a small thing that tells you something about how freight actually works. Between our workshop and a German delivery address, this pallet will be handled by people who never speak to each other and may share no common language. Nothing about the box can rely on a conversation. Everything it needs to communicate has to be printed on it in a form that survives being handled by a stranger at three in the morning.

A shipping carton is a set of instructions to somebody you will never meet.

A label on every single box.

Every carton on the stack carries its own white label with a QR code, not one label for the pallet. That costs more to print and more to apply, and it is worth it for the same reason the serial number on a charge controller is worth it: the moment a pallet is broken down — and it always is, at a depot or at the far end — a box with no identity of its own becomes a box nobody can trace.

If one carton out of a stack goes missing or arrives damaged, we want to be able to say which one, from which batch, holding what. That is not possible if the only identification was on a shipping note stapled to the outside of the wrap.

What a pallet needs at the other end.

This is the part people are most often surprised by, so it is worth saying before delivery day rather than after. A loaded pallet is not a parcel. It arrives on a lorry, it comes off with a tail lift, and it needs firm level ground to be set down on and something with wheels to move it once it is there. A gravel drive, a flight of steps, or a narrow lane a rigid truck cannot turn into are all real problems, and all of them are much easier to solve a week early than on the morning.

So: check access before the pallet is booked, not when it is on the road. Tell us if the answer is awkward. A delivery that has to be attempted twice costs everybody more than a conversation beforehand, and we would rather have the conversation.

And what this page is not.

It is not a customer story. We are not naming who this pallet is going to, what town it is bound for, or what is on the invoice — not in Germany and not anywhere else. What is publishable is the route between two countries and what is printed on the outside of a box, which is all that appears here.

It is also not a promise about your own order. A pallet photographed on its way out is one pallet on its way out. Our product pages say plainly that delivery runs from as little as one day to as long as four months depending on stock, and a photograph of freight does not change that number in either direction.

No declaration, no duty, no border stop.
Just a stack of boxes, a wrapped pallet, and a drive across two countries.

Slovakia and Germany are both member states of the European Union and of the Schengen area, so goods in free circulation move between them without customs formalities; that is a matter of public law rather than a claim about our own arrangements. Nothing here is tax advice, and a buyer’s VAT position depends on their own status and country. The handling pictograms described are the standard international marks for fragile, this way up, handle with care and keep dry. The one-day-to-four-month delivery range is our own published figure from our product pages. The map shows two countries and a direction; it does not show a route, a facility or an address. No customer, order, address or installation is named, described or shown on this page.

What you are actually looking at.

A powder-coated body, a machined top plate, and a steel shaft standing up out of a flange bearing. The blade set bolts onto that shaft. Everything else — the generator, the charge controller, the radio — is inside the box you can see. That is the whole point of the design: there is no separate controller cabinet to find a wall for, and no second run of cable to a shed.

Next to it is the crate it arrived in: plywood, steel-strapped on every edge, corner-bracketed, and lidded with a hasp rather than nailed shut. That matters more than it looks. A turbine that survives manufacture and fails in transit is a warranty claim, a replacement unit and a customer who waits twice. Crates are not marketing.

Reading the front panel.

Down the left are two rows of MC4 connectors. The lower pair is marked INPUTS — wind / solar, the upper pair OUTPUT — inverter / battery, with the polarity stamped above them. MC4 is the connector the solar industry standardised on years ago: keyed, latching, rated for outdoor use, and impossible to mate the wrong way round without deliberately trying. Using it here is not innovation. It is the opposite, and that is the argument for it — a fitter who has wired a solar array has already wired this.

In the middle: a display window and a rotary knob. The knob is the voltage limit, adjustable on the body itself, so the machine can be read and set standing in front of it with no phone and no signal. To the right, a circular multi-pin socket marked SENSOR, and a screw-on antenna for the radio link the Atlas uses to talk to the app. Beside the antenna is a small compartment labelled MyTESUP App 9V (rechargeable battery). The radio has its own power. That is deliberate: the part of the system that tells you what is happening should not go quiet at exactly the moment the rest of it does.

The warnings are the honest part.

There is a yellow triangle on the front that reads HIGH VOLTAGE — OUTDOOR USE ONLY, and a CE mark next to the knob. Neither is decoration. A wind turbine generates whenever the rotor turns, which means the output terminals can be live when nothing is switched on, nobody is expecting it and the machine is lying on the grass halfway through an installation. That is the single most common way people get hurt by small wind, and it is why the sticker is on the front of the machine rather than on page nine of the manual.

A turbine has no off switch. It has a brake, and a brake is something you have to remember to use.

What the serial number is for.

Every Atlas carries two identical labels, one on the front and one on the top plate, each carrying the same serial number and a QR code. Two labels because one of them will end up facing a wall, or under a bracket, or weathered past reading in five years, and a serial you cannot read is a serial you do not have.

On current units the serial begins V7. That is a build code, not a model name — it identifies which generation of Atlas came off the line, and there is no separate product called a V7. What the number buys you is boring and worth having: which unit this is, when it was built and in which batch, so a support conversation starts from a fact rather than a description. If a component turns out to be wrong across a run, the run is identifiable. None of that is visible on a product page, and all of it is the difference between a warranty that means something and a warranty that means a form.

A 15 kW motor in a machine that will never ask for 15 kW.

Inside is a 24-pole permanent magnet generator rated at 15 kW continuous, 22 kW peak — the same motor that goes into the Magnum. The Atlas rotor will never drive it that hard. Our published figures for the Atlas are a 4.5 kW peak and around 1 kW in good wind, which puts the motor under seven per cent of its continuous rating on a normal day.

That gap is the design, not an accident of parts-binning. A generator loafing at a fraction of its rating runs cold, wastes almost nothing in the copper, and is not the component that fails first. Sizing the motor to the rotor instead would save money on the bill of materials and cost it back in service life. It is the least visible decision in the machine and one of the few that you would actually feel, ten years in.

What those numbers mean, and what they do not.

A peak figure is a ceiling measured at a specified wind speed. It is not an average and not a promise. A turbine sitting in a light breeze is not making its peak, and a turbine in a calm week is not making anything at all. Anyone quoting you a daily or annual figure without naming the wind speed it assumes is quoting arithmetic rather than output — multiply any rating by twenty-four hours and you get a number no wind turbine on earth has ever produced.

The honest version is a range that depends on where you live. We publish 0.5 to 8 kWh a day and 180 to 2,500 kWh a year for the Atlas, and the spread between those ends is not hedging — it is the difference between a sheltered suburban garden and an exposed coastal site. After the site, it is the blades: the Atlas takes low-wind, standard and high-wind sets, and fitting the wrong one is the most common reason a correctly working turbine disappoints its owner. Tell us your location and what you are trying to run, and we will tell you which set applies, and whether the answer is that a turbine is the wrong purchase for your site. Sometimes it is.

Where the shaft comes from.

That steel shaft standing out of the top plate does not arrive as a shaft. It arrives as a length of round bar, and two machines in our own workshop turn it into a part. Neither of them is glamorous and both are worth seeing, because this is the half of manufacturing that never appears on a product page.

First the saw. A bar is clamped, flooded with coolant and cut to length — filmed on a phone, nothing staged:

What comes off the saw is not straight enough, not the right diameter anywhere along it, and saw-cut at both ends. Fixing all of that is the lathe’s job.

The lathe the rotor shafts are turned on. Levers, dials and handwheels — no screen and no program.

It is a manual machine. Every dimension it produces comes from a person turning a handle and reading a line on a dial, and every operation takes metal off while none of them puts any back. A shaft turned two tenths of a millimetre undersize is scrap after all the time already spent on it, which is why a good turner creeps up on a dimension rather than aiming straight at it.

Two spindle-speed ranges, a warning in German — and, under the model name, a serial-number box nobody ever filled in.

There is a small joke in that photograph. This page has just spent several paragraphs on why every Atlas carries a serial number, and the machine that turns its shafts has an empty box where its own should be. That is not hypocrisy so much as a difference in purpose: a serial number is a promise to somebody else, and nobody was ever going to need to trace this lathe from another continent.

And this is the work itself, still going:

A machine you can read is a machine you can argue with.
Everything on that panel is a claim we have to stand behind afterwards, which is the only reason to print any of it.

The photographs on this page are of the lathe in our own workshop, unretouched and unstaged; there are no photographs of a finished Atlas here, and nothing above is written as a caption to one. The make, model, CE mark, speed ranges, German warning plate and empty serial-number box are read directly from the machine in those pictures rather than quoted from a specification sheet. The videos are our own footage of the saw and lathe work. The 15 kW continuous and 22 kW peak motor ratings, the 4.5 kW turbine peak and the daily and annual yield ranges are our own published figures; a peak is a maximum at a specified wind speed, not an expected daily or annual output, and turbine output depends entirely on the wind at your own site. The supplier’s plate on the lathe bed carries a third party’s telephone numbers and has been kept out of frame. No customer, order, address or installation is named, described or shown on this page.

What the box actually does.

A wind turbine does not produce electricity you can put in a battery. The generator puts out three-phase alternating current whose voltage and frequency rise and fall with the wind, second by second. A battery wants steady direct current at a voltage it chooses. The Magnum Charge Controller is the box that stands between those two facts: it rectifies the AC to DC, holds the output where you set it, and decides what to do when the wind gives it more than the battery can take.

That last part is the job that matters. Our published figures for this unit are power management up to 15 kW, batteries from 24 to 48 volts, and it works with every TESUP turbine. It also carries automatic turbine protection and a manual emergency brake — because the failure mode of small wind is not the turbine stopping, it is the turbine not stopping.

Every argument you can have about this product is printed on the front of it, in the order you will use it.

Three wires in, two wires out.

Along the bottom edge are three positions marked WIND, with the word TURBINE bracketed underneath them. Three, because the generator is three-phase. There is no polarity to get wrong on those three: swap any two and the machine works exactly as before. It is one of the few connections in a renewable installation you genuinely cannot make backwards, and that is not an accident of the design so much as a happy property of three-phase rectification.

The DC side is the pair of MC4 connectors on the top edge, with + and − stamped beside them. MC4 is the connector the solar industry settled on years ago — keyed, latching, rated for outdoor use, and hard to mate wrongly without meaning it. Using it here is not clever. It is the opposite of clever, and that is the argument for it: an installer who has wired a solar array has already wired this.

Between them sits a circular multi-pin socket marked SENSOR, a three-digit display, and a machined knob. The knob is the voltage setting, adjustable on the box itself. That means the unit can be read and set by somebody standing in front of it in a field, with no phone, no app and no signal — which is where these boxes actually live.

The stub on the left-hand side is the radio. The knob on the front is what you use when the radio is not the answer.

The short black stub screwed into the side is the antenna for the IoT link, which is how the unit reports to a phone. We think remote monitoring is worth having and we ship it as standard. We also think a controller whose only interface is an app is a controller you cannot fix on a wet Tuesday, which is why the knob and the display are still on the front panel and always will be.

The stickers are the honest part.

On the face of every unit in these photographs, in the same position, is a yellow label reading HIGH VOLTAGE! — OUTDOOR USE ONLY. Next to the terminals is a CE mark. Neither is decoration, and neither is there to reassure you.

A wind turbine generates whenever its rotor turns. It does not wait to be switched on and it does not stop because you have opened something. That means the turbine terminals on this box can be live while nothing is powered up, nobody is expecting it and the installation is half finished. It is the single most common way people get hurt by small wind, which is why the warning is on the front of the machine rather than on page nine of a manual nobody keeps.

A turbine has no off switch. It has a brake, and a brake is something somebody has to remember to use.

What the label on each one is for.

Every unit carries a white label with the TESUP wordmark, a serial number and a QR code. On the two labels you can read clearly in these photographs, every field of the serial is identical except the last, which differs by one: the units came off the line one after another and were labelled in order. That is not a detail we are showing off. It is the whole point of the label.

What a serial buys you is boring and worth having. It says which unit this is, when it was built and in which batch, so a support conversation starts from a fact instead of a description. If a component turns out to be wrong across a production run, the run is identifiable and we can go and find it rather than waiting for complaints to arrive one at a time. None of that is visible on a product page, and all of it is the difference between a two-year warranty that means something and a two-year warranty that means a form.

Behind the pallet, on another pallet: flat sheet-metal blanks. That is the same enclosure, several operations earlier.

Do you need one of these at all?

Sometimes not, and it is cheaper for everyone if we say so here rather than after you have bought one. Our Atlas carries its charge control inside the turbine body, which is why that machine has no separate cabinet to find a wall for and no second cable run to a shed. If an Atlas is what you are installing, the electronics in these photographs are already inside it.

This box is the standalone version: for the larger machines, for installations where the controller needs to live indoors while the turbine does not, and for people adding a TESUP turbine to a system that already exists. There are two ways it goes in the chain — turbine to controller to battery, or turbine to controller to grid inverter — and which one applies to you depends on whether you are storing the energy or using it as it arrives. Tell us which, and we will tell you what you need. If the answer is that you already have it, that is the answer you will get.

What “ready for delivery” honestly means.

It means these particular units are built, labelled, on a pallet and waiting for a pallet truck. It does not mean every order ships tomorrow. Our own product page says it plainly, and we would rather repeat it than have you find it in the small print: depending on stock, delivery runs from as little as one day to as long as four months. A photograph of ten finished controllers is ten finished controllers — it is not a promise about your order date.

What it does tell you is the thing a rendered product image never can. These were made, in a building, by people, on equipment that leaves marks on the floor. The pallet is scuffed, the stacker is scratched, the sheet metal for the next batch is stacked behind them. Every manufacturer’s catalogue photograph looks the same. The floor is where they differ.

Ten to a pallet. Count them.

On the forks, about to become somebody’s delivery.

Ten identical boxes with ten different serial numbers.
That is what a batch is, and it is the only claim on this page you can check by looking.

The photographs on this page are unretouched and unstaged, taken in our own workshop. The 15 kW power-management figure, the 24 to 48 V battery range, the compatibility with all TESUP turbine models, the automatic protection and manual brake, the IoT monitoring, the two-year TESUP Care warranty and the one-day-to-four-month delivery range are all our own published figures from the product page linked above. The serial numbers visible in the photographs belong to these units and to no customer; the units were photographed as stock, before allocation to any order. The QR codes on the labels are not machine-readable at the resolution published here. No customer, order, address or installation is named, described or shown on this page.

What a schedule actually is.

A blackout schedule is not a blackout. It is a timetable. Households are put into groups, and each group is told which hours it will have electricity and which hours it will not. When the grid is holding, the timetable is followed and you can plan around it — cook when the power is on, charge everything, fill containers with water. When the grid is hit, the timetable stops meaning anything and the outage becomes an emergency one, which is the kind you cannot plan around at all.

In December 2025 the UN’s human rights monitoring mission in Ukraine reported that most regions were facing scheduled rolling cuts of up to sixteen hours a day, and that after one series of strikes, emergency outages in some areas ran past thirty-six hours. This summer has been easier: in June, the head of Ukraine’s grid operator said the country could expect emergency cuts of up to about five hours a day through July and August. Both of those are real numbers from named sources, and neither of them is a forecast for the coming winter, which nobody can give honestly.

Each of the three figures with its source and its date attached, because presenting the winter numbers as current would be the easiest mistake in the whole piece.

What a small turbine will not do.

This section comes before the other one deliberately. A roof-mounted turbine is a few hundred watts to a few kilowatts in good wind. That is not a generator, and treating it as one gets people hurt.

It will not heat a home. Electric heating is measured in kilowatts held for hours, and no small wind turbine on a domestic roof will carry that in winter. It will not run an electric cooker, an immersion heater or a washing machine at will. It is not a substitute for a hospital, clinic or shelter generator, and anyone specifying power for those should be talking to a diesel supplier, not to us. It also cannot be relied on to produce on any particular day: wind is not a schedule either, and there are calm weeks in winter.

And there is a practical limit that has nothing to do with electricity. Most people living under a schedule live in apartment blocks, where the roof is not theirs, the mounting is not theirs to decide, and a mast on a residential building is a structural and legal question before it is an energy one. This is realistically a thing for houses, not for flats.

A second source does not fix a grid. It changes what a household can still do while the grid is down.

What it will do.

The useful shape is not turbine-to-appliance. It is turbine-to-battery, and battery-to-the-few-things-that-matter. A small wind turbine trickling into a battery bank over a long windy night is doing something a solar panel cannot do at that hour: it is refilling the store while everyone is asleep and the grid is off.

What that store then runs is the modest list: lights, phones and a router, a water pump, a fridge cycling on and off, a laptop, and the charger for whatever else the household depends on. None of that is impressive on a specification sheet. All of it is the difference between an evening that works and an evening that does not.

The wiring is the whole argument. The same turbine is a disappointment on the top row and quietly useful on the bottom one.

Why wind, specifically, in winter.

This is the one argument that genuinely transfers, and it is worth stating precisely rather than generously. Solar has a season; wind mostly does not. In a typical year at Kyiv the December sun delivers about eight per cent of what the July sun delivers, while the wind’s own quietest month is July and even that carries about a third of the energy of its windiest. Wind is not at its best in midwinter — March is windier — but it does not collapse in midwinter either, and sunlight does. A household running on one source has a bad month. A household running on two sources has a bad week, because the two do not fail at the same time.

Checked rather than asserted. February is a genuinely calm month at Kyiv and the chart shows that too, which is the point of drawing it from data instead of from the argument we wanted to make.

That is the same point made in every other post on this blog, and it is not a Ukraine argument at all. It just matters more where the grid is being attacked than where it is merely expensive.

What we are not going to do.

We are not going to publish a customer’s story. We have orders from Ukraine, and every one of them comes with a name, a street and a town attached. Publishing that a particular address has an independent power source is not a testimonial, it is targeting information, and no amount of goodwill makes it safe. Nobody will be named here, ever.

We are not going to run a countdown, a war-themed discount or an urgency campaign. And we are not going to tell you a turbine keeps anybody safe. It runs a light and a router for a few hours. That is worth having and it is not worth exaggerating.

If you are in Ukraine and want to work out whether any of this applies to your building, the useful thing to send us is your situation — house or flat, roof or ground, what you actually need to keep running — and we will tell you honestly if the answer is no. It often is.

The honest version of this is small and dull: a second source, a battery, and a shorter list of things that stop working.
Anyone selling you more than that, on this subject, is selling you something else.

The sixteen-hour and thirty-six-hour figures are from the UN Human Rights Monitoring Mission in Ukraine, published 12 December 2025, and describe last winter rather than the present day. The five-hour figure for July and August 2026 is from Vitaliy Zaichenko, chief executive of Ukrenergo, in an interview with RBC-Ukraine published 25 June 2026. We have given no forecast for the coming winter because we have no basis for one. No customer is named here, no order is described, and no location of any installation is published. The map at the top shows Ukraine’s internationally recognised borders, Crimea included; the public-domain Natural Earth basemap we drew it from does not, so we corrected it, and we say so rather than leave a border quietly redrawn either way. It shows no front line, because we have no source for one worth putting on a page. The monthly sun-and-wind chart is built from the European Commission Joint Research Centre’s PVGIS v5.2 typical meteorological year for Kyiv, with radiation from PVGIS-SARAH2 and wind from ERA5, drawn from 2005 to 2020; wind is plotted as the mean cube of the ten-metre wind speed, which is the energy available in the wind and not the output of any particular turbine, and a typical year composes each month from a different real year. Turbine output depends entirely on the wind at your own site and the figures on our product pages are our own published data.

What you are looking at, in order.

The first shot is a screen, not a machine, and that is where every part actually starts. The red and yellow shapes are the parts, laid out on a sheet. Arranging them so that as little steel as possible is left over is called nesting, and it is the least glamorous cost saving in manufacturing: the same parts, the same machine, the same minutes, and a smaller bill for material because somebody spent ten minutes packing the drawing tighter.

Then the bed. The black ridged strips the sheet rests on are slats, and they are consumable — the beam cuts into them a little every time, and eventually they get replaced. The sheet sits on top and does not move. The head moves.

Then the part that is worth watching twice: the sheet after the cut, with the parts still sitting in their own outlines, and the slats underneath glowing orange. That glow is the heat that went into the steel and did not leave with the part. It is also the reason the shot exists — a cut edge photographs as an ordinary line five minutes later, and looks like this for about thirty seconds.

The next bench along. Parts cut on that machine end up inside these.

The boring part is the whole point.

Nothing in that clip is dramatic, and that is the argument. When somebody else cuts your parts you pay for four things: the part, their margin, the freight, and the wait. You also accept their minimum order, which is how you end up buying five hundred of something because that is the smallest run they will start, and carrying the other four hundred and twenty on a shelf until you need them.

Cutting them here removes the margin, removes the freight, removes the minimum order, and shortens the wait from weeks to that afternoon. It is not a clever strategy, it is arithmetic, and it is most of the reason a home wind turbine from us costs what it does. The longer version of that argument, including the parts we still buy from people who make them better than we would, is in what buying a machine actually buys you.

A machine that runs is an asset. A machine that runs one day a week is a more expensive way of buying the part.

What the video does not show you.

It does not show the invoice, the maintenance contract, the extraction filters, the compressed air, or the operator who had to be trained before any of it produced a usable part. It does not show the days the machine sits still. A laser only beats outsourcing at volume, and the honest version of this post says so: we buy machines when the work is already there, not to have something impressive to film.

It also does not show quality control, which is the half of the job that happens after the cutting. A part being the right shape on the day it was made proves very little. Somebody has to keep proving it, on their own equipment, on a routine, at a cost nobody enjoys paying.

The short version.

Same footage, cut for a phone, if that is where you would rather watch it.

In a year that machine will be an unremarkable thing in the corner of a workshop, covered in swarf, with somebody’s coffee on the control cabinet.
The only trace of it will be a price that did not go up.

The footage is our own, filmed at our own factory on an ordinary production run, and is unedited apart from trimming, stabilisation and colour correction. The machine is a BODOR fibre laser that has been in service for about two years. No customer is named here and no order details are published. We have given no figure for what the machine cost or what it saves, because we could not show you the calculation — and a number you cannot check is worth nothing. Turbine specifications referenced are our own published data and are checkable on the product page.

That last point is usually something a manufacturer would bury. We are going to lead with it, because for a classroom it is not a shortcoming. It is the entire reason these are worth having.

What is actually in the box.

Each crate holds a complete set: the turbine itself, its blade set, and a charge controller with a dump load. Nothing has been removed and nothing has been used. They have simply sat in a dry warehouse since 2023 while we shipped newer stock.

The dump load is worth a paragraph of its own, because it is the part people do not expect and the part a physics teacher will like most. A wind turbine that is spinning has to push its energy somewhere. If the battery is full and the machine is left connected to nothing, there is no electrical resistance to slow the rotor and it will run away with itself. The dump load is a resistor that takes the surplus and turns it into heat. It is a safety device, and it is also the most visible piece of physics in the whole system: when the batteries are full, the dump load gets warm, and a class can put a hand near it and understand conservation of energy without anyone drawing a diagram.

Forty complete sets. The third number is the one that matters for a school.

The thing that dates them is the thing that suits a classroom.

These are not connected devices. There is no radio, no app, no cloud account and no dashboard. In 2023 that was ordinary. Today it reads as old-fashioned. For a school it is three separate advantages, and none of them are marketing.

The first is paperwork you do not have to do. A connected device on school property means somebody has to answer what it transmits, where that data goes, and who processes it. A machine with no radio raises none of those questions, because there is nothing to ask about.

The second is that nothing can be taken away from you. Connected hardware stops working when the manufacturer stops paying for a server, and that has happened to a great deal of good equipment. This turbine has no such dependency. It will behave in 2045 exactly as it behaves on the day it is bolted down, whatever has become of us by then.

A connected turbine shows a pupil a number on a screen. This one makes them go and measure it.

That is the third advantage, and it is the real one. An app hands over a figure and hides everything behind it. A charge controller with accessible terminals is an instrument: a class can put a multimeter across it, log voltage and current against wind speed, plot a curve, and argue about why the curve is not the shape the brochure implies. You cannot do that with a sealed appliance. You can do it with this all day.

One of the forty, opened for this photograph. Turbine, hardware and the boxed controller, exactly as they were packed.

Free to schools. Half price to resellers.

If you are a school, a college, a university department or a training centre, the turbine is free. Not discounted — free. If you are a reseller, the same stock is available at half price. Either way, the route is the same: create or sign in to an account and contact us from there, so the enquiry arrives attached to a real address we can quote shipping against.

Please be direct with us about what you are and what you intend to do with it. Forty is not many. We would rather they went to forty places that will actually put them up than to four hundred that are curious.

What we are not giving you.

This is the part we would ask you to read twice, because a free turbine that nobody planned for is not a gift, it is a liability with a two-year warranty on it.

We are giving you the machine. We are not giving you the installation. On a school site that means, at minimum: somebody competent confirming the structure or the foundation can take the loads; whatever planning or landlord consent applies where you are; the electrical work done and signed off by a qualified person; a risk assessment; your insurer told; and the mast sited or fenced so that it is not in the middle of where children play. None of that is unusual for a school, but all of it has to happen before the crate is opened, not after.

And one more, which is the one that actually decides whether this works: somebody has to own it. A named person whose job includes checking the fixings each autumn and knowing how to brake the machine before a storm. If that person does not exist, the turbine becomes a seized ornament in three years, and that teaches a lesson none of us wanted to teach.

Before you ask us for one.

A windy country is not a windy playing field. National wind maps say very little about a site enclosed by a sports hall, a line of trees and a three-storey teaching block. If you have a term to spare, measure first: an anemometer on the proposed mast position, logged through a windy season, will tell you more than any map and makes a better piece of coursework than the turbine will.

If the answer comes back that your site is sheltered, we would rather you knew that before we shipped a crate across a continent. Tell us and we will say so. There is no version of this where we want a turbine standing still in a playground with our name on it. The full specification for the Atlas range is on the product page, and the figures there are the ones to design against.

The rest of them, still banded. Loaded the same way as any other order — the only difference is the invoice.

Forty machines that cannot be updated, cannot be tracked, and cannot be switched off from somewhere else.
We think that makes them worth more to a classroom than they ever were to us on a shelf.

Forty complete sets are available at the time of writing: turbine, blade set, and charge controller with dump load, boxed in 2023, unused and not refurbished, each carrying a two-year warranty. They are free to schools, colleges, universities and training centres, and half price to resellers. Installation, structural assessment, planning or landlord consent, electrical work, certification and insurance are not included and remain the responsibility of the recipient. When the forty are gone this offer ends, and we will say so on this page rather than quietly leaving it up. No customer is named here. The turbine specification is our own published data and is checkable on the product page.