Choosing a Wind Turbine

Which wind turbine suits an off-grid setup in Australia or New Zealand, and what it will and will not do

Solar stops at sundown and struggles all winter. A wind turbine keeps charging whenever the wind blows, day or night. That is the whole case for one. Everything below is about picking the right size, knowing what it cannot do, and not buying the wrong parts around it.

1. Start with your site, not the wattage

Start with two questions: how much wind does your site actually get, and how much room do you have.

Rated power is measured at the maker's rated wind speed, 10 to 13 m/s depending on the model, which is about 36 to 47 km/h. What you get at your place depends on your wind, your mast height and the season, not on a number on a website. The blades start turning in a light breeze, but turning is not charging: charging starts once the wind clears the cut-in speed of about 3.5 m/s, and output climbs from there.

We publish the measured power curve for every horizontal turbine on its product page, so you can read off what a given wind speed delivers. The maker has published no curves for the vertical models, so we do not quote output figures on those.

2. Vertical or horizontal

	Vertical axis	Horizontal axis
Best in	Swirling, shifting wind	Clean, steady wind
Suits	Rooftops, tight blocks, near neighbours	Open ground, a mast
Goes up to	2 kW	5 kW
Noise	Most of what you hear is the wind itself	A chopping note as each blade passes the mast

In the same clean wind a horizontal makes more of it. A vertical trades that away for taking wind from any direction without turning to face it, which is why it wins on a roof, in a gully, or anywhere the wind never settles. Vertical turbines (the X-300, and the H12 and HPRO series) start turning in about 2 m/s. Horizontal turbines (the M-400, M-600, M-800, and the L1, L2 and G series) want a clear run at the wind and scale further, and most of them survive heavier weather.

3. Which size for what you are running

What you're running	Look at	Rated
Boat, caravan or camper	X-300, M-400	300 to 400 W
Cabin, donga or off-grid home	M-600, M-800, L1 series	600 W to 2 kW
Off-grid house with sheds, farm or worksite	L2, G, H12, HPRO series	2 kW to 5 kW

Match the turbine to your battery bank, not to the biggest number. The largest models generate at 220 to 240 V, the same band as Australian and New Zealand mains, and need a mast, not a roof. The L2-3000, G-3000 and G-5000 are ground-mount only: they need a 10 to 15 m mast and are not rooftop units. Whichever you pick, the turbine never connects to your mains. The controller converts its output to charge a battery bank.

4. 12, 24 or 48 volts

You must match the turbine and its hybrid controller to the exact voltage of your existing battery bank:

• 12 V: compact mobile setups. Caravans, 4WDs, camper trailers, a tinnie.
• 24 V: medium setups. Off-grid sheds, cabins, motorhomes, a boat.
• 48 V: most of this range, and the sensible choice for a full off-grid system. Higher voltage means less current in the cable, so less loss over a long run and lighter cable.

5. What wind will not do

• Not 24/7 power. It makes power when the wind blows and none when it drops. A turbine assists solar; it does not replace it.
• No output promise from us. The number on the box is a peak rating at the rated wind speed. Your display shows what the wind is delivering right now, and it will sit well below the rated figure most of the time. That is physics, not a fault.
• Not plug-and-play. It needs a hybrid controller, a dump load, and cable and breakers to wire it up, and a licensed electrician to install it.

6. The parts you must have around it

A wind turbine generates "wild" three-phase AC power that changes voltage constantly with the wind speed. Connecting it directly to a battery or a standard solar inverter will destroy your equipment. The system runs in this order:

1. Wind turbine: generates fluctuating three-phase AC.
2. Hybrid wind and solar charge controller with a dump load resistor: converts that to steady DC and protects the turbine from over-speeding.
3. Battery bank (12, 24 or 48 V): stores the energy and smooths the gusts.
4. Off-grid inverter: connects to the battery and makes 240 V AC for your appliances.

The dump load resistor is not optional. When your battery bank is fully charged it stops accepting power. If a storm hits at night with the batteries full, a turbine with nowhere to send its power will free-spin out of control and can physically fly apart. The controller diverts the excess into the dump load, which burns it off safely as heat and acts as an electronic brake.

Between the mast and the controller, keep the cable run to roughly 2 to 10 metres where you can, and use heavy cable on longer runs. Thin cable over a long run loses the power as heat before it reaches the controller, which shows up as the same "spinning but 0 W" symptom as a settings problem. Fit a DC-rated breaker before the controller and another after it, landing on a DC bus bar, so you can isolate the controller from either side. Our hybrid controllers and cable, breakers and bus bars are in their own collections.

7. Noise, neighbours and mounting

A horizontal turbine makes a chopping noise as each blade passes the mast. The verticals (X-300, H12 and HPRO) take wind from any direction with no yaw mechanism, and the HPRO series runs on a magnetic-levitation generator, so most of what you hear is the wind itself. They suit suburban blocks, caravan parks and sites close to neighbours. Any turbine mounted on a building carries vibration into the structure; a pole or mast away from the house is the quieter install. Council rules on height and placement vary by state and shire, so check with yours before you order a mast.

8. Delivery and what it costs

Turbines are built to order and shipped from the factory, so delivery is priced to your door by postcode. Put your postcode in on the product page to see the sea price (4 to 6 weeks, allow up to 7 for WA and regional addresses) and the air price (around 2 to 3 weeks), then pick one at checkout. New Zealand customers choose New Zealand on the product page; freight shows in Australian dollars and is converted to NZ dollars at checkout. Remote areas, the Northern Territory, Tasmania and New Zealand's island postcodes are quoted individually. The five biggest turbines, the G-3000, G-5000, H12-2000, HPRO-1000 and HPRO-2000, ship in cartons over 2.5 metres long and are quoted to your exact address before you order. Call 0400 333 898 or email Quotes@BushLine.com.au with your postcode.

9. Before you order

• You know your battery bank voltage, and the turbine and controller you are buying match it.
• You have a clear site for the turbine: a roof or tight block for a vertical, open ground and a mast for a horizontal.
• You have budgeted for the hybrid controller with dump load, the cable, the breakers and the bus bar, not just the turbine.
• You have a licensed electrician lined up. Installation by a qualified specialist is a safety requirement and a warranty requirement.
• You have read the install and start-up guide, and you know where the 0 W troubleshooting guide is for the first week.

Browse the full range: Wind Turbine Power.