Suburban wind power generation practical?

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#3381798 8-Jun-2025 19:26

mudguard:

I veiw it a little bit like water though. In Auckland it seems ludicrous that water storage isn't mandatory for housing. We get so much water during winter that it would a decent difference if each household hung onto some of it.

It seems that way until you cost it out. It almost always works out that it is cheaper to centrally provide water storage and distribution as well as providing a higher quality product.

tweake

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#3381799 8-Jun-2025 19:36

Handle9:

New Zealand has done much the same though EECA and insulation/heat pump subsidies.

yes. however the difference is scale. NZ insulation is only for retires or community services card. usa i think is open to everyone (may be a income limit, i would have to ask). nz its simple things, usa is an energy audit on the house ie paid pro's go and test homes. very big differences between us and them.

some of the commercial stuff that i see is getting a compressed air audit done and power co chips in hundreds of thousands for new gear etc, making it a pretty quick pay back period for the company. i don't recall nz power co's paying for a customers upgrades so they can buy less power from them.

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#3381805 8-Jun-2025 20:03

tweake:

Handle9:

New Zealand has done much the same though EECA and insulation/heat pump subsidies.

yes. however the difference is scale. NZ insulation is only for retires or community services card. usa i think is open to everyone (may be a income limit, i would have to ask). nz its simple things, usa is an energy audit on the house ie paid pro's go and test homes. very big differences between us and them.

some of the commercial stuff that i see is getting a compressed air audit done and power co chips in hundreds of thousands for new gear etc, making it a pretty quick pay back period for the company. i don't recall nz power co's paying for a customers upgrades so they can buy less power from them.

New Zealand power companies don't administer energy efficiency schemes. EECA does. Power companies are charged to fund EECA.

I don;t believe there are US wide schemes for home owners funded by utilities, there is no single energy market in the US and states have a lot of independence.

The big round of insulation funding in NZ was in 2009 when 235,000 houses were insulated at a cost of $247 million. It was open to pretty much anyone from memory. We did our house and certainly weren't low income earners.

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#3381806 8-Jun-2025 20:10

Found it, the scheme was called Warm Up New Zealand: Heat Smart.

It was open to anyone with a house built before 2000 and subsidised the 1/3 cost of insulation up to $1300. If you were a low income earner you could get that topped up to a 60% subsidy and then there was some third party funding available on top as well as subsidies for heat pumps.

https://www.iea.org/policies/2079-warm-up-new-zealand-heat-smart

MartinGZ

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#3381863 8-Jun-2025 21:56

Back to the OP

timmmay:

Is generating power from the wind practical in suburban New Zealand?

If you have a properly sited wind turbine then it can be worth doing the sums - clear air, 7+ metre pole, 5 kW plus, good wind speeds.

However if you are talking about the small BUWTs (Building Integrated Wind Turbines) then save your money. In the 1990's and early 2000's there was a lot of interest in this and I researched this for a client. Unfortunately I no longer have access to my reports although my recommendation was a strong no. Typically BUWTs are sited in turbulent air (bad) and have unproven design. Urban areas typically do not have good wind speeds (ignoring Wellington of course).

Some reading:

Warwick Wind Trials, UK. Site still exists but no documents https://warwickwindtrials.org.uk/index.html

Final report was found here: https://s1.solacity.com/docs/Warwick%20Wind%20Trials%20Report.pdf

"The average energy generated per turbine per day across the sample set has been 214 Wh (including
times when turbines were switched off for maintenance or due to failures). This is equivalent to an
average of 78 kWh of energy produced per site per year and an average capacity factor of 0.85%. (This
compares to typical capacity factors of between 10% and 30% for larger turbines on free standing sites in
good areas)."

Paul Gipe is one of the leading wind experts, and an absolute sceptic of BUWT. Main site for this topic, loads of reading - have fun: https://wind-works.org/wind/small-wind/rooftop-and-urban-wind/

A typical content:

"In March of 2015, the turbines generated a whopping 0.12 kWh. (Yes, the decimal is in the right place.) From the manufacturer’s power curve and the wind speeds at the time, the turbines should have produced 7.8 kWh. Let’s see, that’s overestimating the generation by a mere 65 times."

https://wind-works.org/rooftop-and-building-integrated-wind-turbines-are-a-failure-says-nrel/

Manufacturers over estimating output is a common theme.

I've not looked at this for 20 years, but having a quick look through Paul's website, nothing has changed and the snakeoil salesmen still keep on the treadmill.

My advice is to keep your hand in your pocket, unless you are using PROVEN technology. Always find independent verification of output data - mostly it does not exist.

SomeoneSomewhere

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#3381865 8-Jun-2025 21:58

I don't think I've ever heard of a capacity factor as bad as 0.85%.

That's just... OMG.

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MartinGZ

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#3381870 8-Jun-2025 22:29

If all the downtime was excluded, the average ~~load~~ capacity factor rose to a heady 4.15%. But you cannot exclude downtime if you are looking at viability.

SomeoneSomewhere

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#3381871 8-Jun-2025 22:31

It looks like the bulk of the downtime is because they had to be switched off for noise reasons, which... not really helping their case that much.

gzt

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#3381874 8-Jun-2025 22:54

tweake: water of course has hygine requirements

That is true. There are also many uses of water that do not have hygiene requirements. Domestic toilet flushing, car washing, gardening, etc. Many but not all retail and industrial uses. Rainwater collection and usage is not practical in all cases. In many other cases, I believe it is.

raytaylor

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#3381875 8-Jun-2025 23:01

timmmay:

Is generating power from the wind practical in suburban New Zealand?

A friend of mine lives next to a small wind turbine that her neighbor put up in their back yard. I think it does lighting in their shed. One of those DIY people thats always trying to save themselves some money because they think they know better.

I use wind turbines at our remote hilltop transmitter sites - so I dont mind them. But I couldn't live next to one.

Sitting in her back yard its as annoying as someone's wind chimes.
Thankfully she cant hear it much in the house and most days its silent.

To really get the most of a wind turbine it needs to be about 12 metres above any obstructions where the wind flow is smoother and less gusty. If its at the same height as nearby tees or only slightly higher than buildings, then the wind will be too gusty and the turbine will regularly shut down to protect itself.

The initial cost of the turbine, as well as the fact you need to pull it down and send it away for servicing and bearing replacement every 2-3 years makes it pointless when you can just buy electricity from the grid at a much cheaper rate.

For low power offgrid DC applications they work well where the cost of bringing the grid to the site is the barrier.
Despite the marketing graphs, they dont produce much unless the wind is blowing over 30km/h
I very much like the Air X Marine turbines - when installed properly they work very well and seem to have the best performance.

We have also tried vertical axis turbines. The best one of the 3 models we tried, was the LE-v150. But you need a lot more wind for a VAWT to start producing and they are much more bulky for the output. They also dont produce anything unless the wind is blowing over ~40km/h. We couldnt make them work at a few sites so went back to using the horizontal models.

In most hilltop installations, across a few types of turbines I have tried, we are lucky to get about 800kwh per year out of them. Over a 6 year lifespan thats 4,800kwh if all goes well.
For the same cost as a decent Air X Marine, we could be buying 16,000kwh from the grid.

So if you spent money on a wind turbine and expected to sell excess power to the grid, you would be selling it at a loss. And then loosing more money when you buy it back later.

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mudguard

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#3381890 9-Jun-2025 06:55

gzt:
tweake: water of course has hygine requirements

That is true. There are also many uses of water that do not have hygiene requirements. Domestic toilet flushing, car washing, gardening, etc. Many but not all retail and industrial uses. Rainwater collection and usage is not practical in all cases. In many other cases, I believe it is.

That's what I was thinking rather than purely drinking water. I was visiting a friend during summer and noted all the lovely watered berms, whereas obviously if we go to water restrictions we barley water the garden. However a water tank doing the toilet and watering the garden ought to last well into summer.

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mudguard

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#3381891 9-Jun-2025 06:58

pdh:

But we insist that 'they' provide us power in a Dunkelflaute - and they must supply us all - and all the power we might ask for. To be available, they have to maintain a full-size & very reliable 'backstop' power supply & grid. Machinery, people, maintenance, etc. All sitting there - waiting to be needed.

On that note, what percentage of current power generation infrastructure hasn't been taxpayer funded?

timmmay

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#3381925 9-Jun-2025 09:29

Thanks all, interesting discussion. Thanks @MartinGZ and @raytaylor for sharing your experiences. Sounds like wind power is not near ready for mainstream use in the suburbs.

Interesting discussion about renewables as well. Since they're unreliable we do need the central generation to be capable of supplying the peak load, but I guess distributed generation reduces the load on them some of them time which means less water put through the dams leaving more for when the renewables aren't available. Storage really is looking to be key.

wellygary

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#3381986 9-Jun-2025 10:03

mudguard:

On that note, what percentage of current power generation infrastructure hasn't been taxpayer funded?

Pretty hard to unwind that knot,

Until the 80/90s everything was state owned, but people still paid power bills,

- If the government stumped up the cash for a new dam in 1950, but the state power company made a profit for the next 10 years which went back to the government, did the taxpayer pay for the dam??, or did the power users simply use the government as a bank and they paid for it over time??

shk292

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#3382013 9-Jun-2025 11:24

Speaking as a yachtie, I’ve seen quite a few wind turbines on yachts but they seem to be gradually going out of fashion and being replaced by solar panels. There are a few boats with them on the same marina as mine, and when they are generating power in a useful wind, they are noisy. Not noisy enough to prevent conversation, but within about 50m they are very annoying and if any of my neighbours at home installed one I would be having a conversation first and making a noise complaint soon after. Obviously different models have different noise levels, but I’m quite surprised anyone would put up with the ones I’ve seen on a yacht.

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