1KW 48V Horizontal Wind Turbine

For most sites in New Zealand, probably not, and the only thing that decides it is your average wind speed.

Power in the wind goes with the cube of the speed. Double the wind and you get eight times the power, halve it and you get an eighth. So a site averaging 4 m/s and a site averaging 6 m/s are not 50 percent apart, they are nearly a factor of three apart. Nothing else in the system moves the number that much.

Ours start turning at 2 to 2.4 m/s and start charging at 2.5 to 3 m/s, and every output figure we publish is quoted at 5 to 5.5 m/s. If your site sits well under that for most of the year, put the money into panels instead and we will tell you so.

Exposed coastal sites, ridge lines and open rural land are where wind outperforms. A sheltered suburban section with houses and trees around it is not, at any tower height.

At the wind speeds they are quoted at: the 400W does about 70 kWh a month at 5.5 m/s, the 1KW about 175 kWh a month at 5.5 m/s, and the 3500W about 450 kWh a month at 5 m/s.

Those are monthly averages, not daily output. Wind arrives in bursts and the machine spends a good part of its life doing nothing at all, which is normal and is not a fault.

The watts on the label is the peak the machine can hit, never what it makes continuously. A 1KW turbine producing 175 kWh in a month is averaging about 240W across that month. Judge a turbine on its kWh figure and its rotor diameter, not on its rated watts.

Budget for four things, not one: the turbine, the tower, the controller and the battery bank. The turbine is often less than half the total.

Our smallest is a 400W at around $1,100 and a 1KW horizontal is around $1,800. The 3500W comes as a kit with its controller at around $9,000. A 6 metre tower kit is around $1,070 for the 400W and around $1,590 for the 1KW, and on top of that there is the concrete, the cable run and a wind controller with a dump load.

If you already have batteries and an inverter from a solar system, adding wind is far cheaper, because all you are buying is the generation.

Both, if the site suits it. They complement each other properly: wind is strongest in winter, which is exactly when solar generates least and you are using the most.

If you can only do one, do solar. It is cheaper per kWh, it has no moving parts and it works nearly everywhere. Wind earns its place as the winter half of a system that already has panels.

Run each generation source into its own controller and then both into the same bank. The battery is the buffer between generation and consumption and it does not care where the amps came from. That is the right way to think about the whole system rather than component by component.

Horizontal gives you far more output per dollar. Our 1KW horizontal is around $1,800. The 1KW vertical, which comes as a kit with its controller, is around $4,972.

The vertical takes wind from any direction without having to turn into it, and it starts turning at 2 m/s against 2.4 m/s for the horizontal. It is a five blade aluminium alloy wheel, 1.9m across and 2.4m tall, so it also looks very different on a section.

Compare rotor diameter, not rated watts. The 1KW horizontal sweeps a 2.4m circle and the 3500W sweeps 3m, which is 7.3 square metres. Swept area is what collects the energy.

No, and it is the most expensive mistake in this category.

A turbine puts out three phase AC at a voltage that climbs with wind speed, so it has to be rectified before anything can use it. That is the easy part. The hard part is that a turbine must never be left with nowhere to send its power. Once the battery is full a solar controller simply stops taking current, which for a panel is harmless and for a turbine means it is now unloaded, free to overspeed, and it can destroy itself in one gust.

A wind controller instead dumps the surplus into a resistive load, called a dump load, and can brake the turbine. Ours come with the matching dump load in the box.

See the wind and hybrid charge controllers

Higher is better and it is not a small effect. Wind speed rises with height, and more importantly the wind gets cleaner. Everything upwind of you, buildings, trees, fences, leaves turbulence behind it, and turbulence is what wears a turbine out.

Our tower kits are 6 metres, two 3 metre sections, bolted to a flange at the top of the turbine. That is a practical minimum on a clear site.

The rule of thumb the industry uses is to clear everything practical within about 100 metres of the tower down to at least 10 metres high. If your site cannot do that, the turbine will underperform whatever you spend on it, and you are better off putting the money into panels.

Quieter than most people expect. Ours measure under 20 dB at 5 metres behind the turbine in a gusting 5 m/s wind, and the 3500W is under 30 dB.

What people actually end up hearing is rarely the blades. It is vibration carried down the tower and into whatever the tower is bolted to. Put it on its own foundation, away from the house, and never on the roof of where you want it quiet.

They are built to sit through it. Survival wind speed is 40 m/s, 144 kph, on the 400W and the 1KW, and 50 m/s, 177 kph, on the 3500W.

Two brakes work together. From about 14 to 15 m/s the blade aerodynamics begin limiting rotor speed, and there is an electromagnetic brake as well. Between them the rotor stays inside its rated maximum RPM even as the wind keeps rising, so the machine goes on generating in weather that would have shut an older design down.

Your controller can also short the turbine phases together to stop it, which is how you could park the machine to work on it.

Not with these. Everything in this category is off-grid generation: the turbine charges a battery bank and your inverter runs the house from the bank.

Grid connection is a different machine and a different process, and it needs your lines company to approve it before anything goes up.

If you are on the grid now and want to cut the bill, the usual answer is solar, with wind added only if the site is genuinely windy. Tell us where you are and we will give you a straight answer on whether it is worth it.