Is a wind turbine suitable for my needs?

GustyGardenGalaxy

Firstly, I own a small field that adjoins my bungalow which is surrounded by other large fields belonging to farmers, so installing a decent free-standing wind turbine shouldn't be a problem. Wind in my fairly exposed location isn't in short supply either. Digging a trench for cables shouldn't be an issue either.

I do of course realise that I would need planning permission.

However, what size of turbine should I be looking at? I want to power my small bungalow and would also be looking to replace my oil boiler with an electric boiler so that the wind turbine can provide power for that too for hot water and central heating.

I have a small outbuilding where batteries could be located.

Naturally I'm not going to need a huge turbine of the sort seen in wind farms, but roughly what size would I need for my property?

Is there a recommended online site that I could use to look into potential costs, maybe get in a suitable engineer to do an assessment, etc?

One concern of mine is birds - I don't want them being decimated by turbine blades.

QrizB

For most people, the answer to the question "would a wind turbine be suitable" is "no". You're a slightly less clear-cut case as you have space and might even have sufficient wind.

How much electricity do you currently use in a year? And how much oil?

The Rutland 1803, for example, will cost £3000 (just for the turbine) and might generate 1000-1500kWh/yr (see chart):

A similar £3000 sum spent on solar PV might be expected to produce at least twice as much electricity.

Moving up a size class, the SD3 turbine costs £11k (just for the turbine) but will generate 8-10000kWh/yr under the same conditions:

However £11k spent on solar PV would still produce more electricity and without all the ongoing maintenance costs of a wind turbine.

Have you considered a ground-mounted solar PV installarion instead of a wind turbine?

Martyn1981

My sister has a reasonably good location for a wind turbine, on her small holding. I ran through the numbers with her, and it was around £15k+ for a 2.5kW WT, generating about 4,000kWh pa. Maintenance costs also need to be considered.

Instead they installed 10.3kWp of PV on the south facing roof for just over £8k (scaffolding was already in place), and have generated approx 11MWh/pa for the 2yrs since install.

Obviously wind has a much better generation profile for space heating, but it's expensive on the small scale.


QrizB raises a great point regarding ground mount PV. Purely playing around now, but using my sister's numbers, and installing 20kWp (against that £15k+ WT cost), at a steep 60d pitch to optimise winter generation, I get monthly generation figures from PVGIS of 813kWh Dec, 869kWh Jan, 1,242kWh Feb, which would certainly contribute to the consumption of an ASHP.

Reed_Richards

AFAIK, nobody who posts here actually has a wind turbine.  So can I respectfully suggest you try another forum, perhaps one for those living off-grid?  But before you go, a couple of quick thoughts:

If you generate enough energy to meet most of your needs most of the time then there will undoubtedly be times when you are generating much more energy than you can use.  With a wind turbine my understanding is that you have to use this energy somehow, or export it.  If you want to export then you would need permission from your DNO so you would have to be certain that this would be forthcoming.  Or build a swimming pool and heat that with any electricity you have going spare.

If you have electricity coming out of your ears then an electric boiler is a great solution.  But if you have less electricity and need greater efficiency then a heat pump would be about 3 times more efficient than an electric boiler. 


  

Screwdriva

Reed_Richards said:

AFAIK, nobody who posts here actually has a wind turbine.  So can I respectfully suggest you try another forum, perhaps one for those living off-grid? 
  

Not entirely accurate - I do own a Southwest 1kW micro turbine, 15 years on and still running. I used to install off grid hybrid (PV/ micro wind) systems for charities in the 2000s (think 150W BP Solar panels and Lead Acid batteries), several of which are still operational.

We always designed systems based on user consumption patterns:

- If the goal here is maximum absolute generation per £ spent, a field based Solar PV bifacial panel system would make more sense. Others have shared excellent feedback - I would only add two additional points: 1) Even the best PV installation will generate <20% of the summer "peak" monthly generation in the winter months. You won't be able to power much without a large battery bank 2) The national grid has over indexed on wind generation and severely under indexed on Solar PV (<5% in 2023). This means that future variable export tariffs may compensate PV customers disproportionately when the wind isn't blowing....well that's my bet anyway. 

- If the goal is to consume the energy you produce in the winter months for electrified heating, which it sounds like it is, the SD3 turbine will generate multiples of what any PV system will from November to March annually, during daytime and night. It will likely cost £17K or more installed, depending on tower/ pole complexity. If you decide on wind, I would recommend focussing your negotiating prowess on acquiring the maximum possible duration warranty + maintenance package, as the turbine is essentially an alternator with electronics, blades and bearings. 

You won't kill many birds but you will be able to hear it on windy days if the house is within 50 yards of the turbine. The best news is that SD Energy won't charge you for an initial assessment/ estimate. Let us know how you get on!

P.S. For what it's worth, if it was my home, I'd invest in a Ground Source Heat Pump (~£15K installed after grant with slinkies) and a field based Solar PV that will subsidize it. 

Reed_Richards

I accept that solar panels will give you more electricity per £ spent than any likely wind turbine choice.  But they will give you that electricity when you need it least, unless you spend a lot on air conditioning.  As @Screwdriva points out, you might find that a wind turbine would match a greater proportion of your actual electricity demand than solar panels.  I wonder if somebody has done an estimate for an electrically-heated house?

Martyn1981

Screwdriva said:

Reed_Richards said:

AFAIK, nobody who posts here actually has a wind turbine.  So can I respectfully suggest you try another forum, perhaps one for those living off-grid? 
  

Not entirely accurate - I do own a Southwest 1kW micro turbine, 15 years on and still running. I used to install off grid hybrid (PV/ micro wind) systems for charities in the 2000s (think 150W BP Solar panels and Lead Acid batteries), several of which are still operational.

We always designed systems based on user consumption patterns:

- If the goal here is maximum absolute generation per £ spent, a field based Solar PV bifacial panel system would make more sense. Others have shared excellent feedback - I would only add two additional points: 1) Even the best PV installation will generate <20% of the summer "peak" monthly generation in the winter months. You won't be able to power much without a large battery bank 2) The national grid has over indexed on wind generation and severely under indexed on Solar PV (<5% in 2023). This means that future variable export tariffs may compensate PV customers disproportionately when the wind isn't blowing....well that's my bet anyway. 

- If the goal is to consume the energy you produce in the winter months for electrified heating, which it sounds like it is, the SD3 turbine will generate multiples of what any PV system will from November to March annually, during daytime and night. It will likely cost £17K or more installed, depending on tower/ pole complexity. 

Hi. I'm not sure that's correct (my bold), but I have to cheat quite a bit (a lot).

You say generation per £ spent, so for £17k, as I mentioned earlier, I believe you could install more than 20kWp of PV ground mount.

Using my sister's location in S. Wales, where a 2.5kW turbine would work well and generate 3,500-4,000kWh pa - 20kWp with the PV mounted at 60d pitch to maximise winter gen, the Dec to Feb gen would be approx 2,900kWh, the Nov to Mch gen would be about 5,800kWh. [Edit - full year approx 20,300kWh.]

I'd assume a 3kW WT would generate ~4,500kWh if well located, per year.


Now, I say I'm cheating, as the WT would probably peak at ~3kW, but let's say less thanl, 3.68kW, so it may be simpler for DNO issues. And total battery size may be a tad less, as the gen will be spread across day and night, or more correctly daylight and the rest of the day (as you mention) since the gen window is smaller for PV in the winter.

Second cheat, in my sister's example, I did persuade them to get 3phase installed when they were renovating the property as it was literally across the road at the pole, so cheap (about £2k). So even 20kWp is possible, at a push.*

*Winter fine, with leccy space heating and 3phase export limit of 11kW, plus some batts. But summer would mean capping, unless very large batts, BEV's and a hot-tub.



Moving on - I've chatted for years (over 10) with folk that have WT's, on several forums. Most of those folk are off-grid. I've noticed their (off-gridders) excitement as PV costs fell, and they started to install PV. Just the fact that the charge controller could manage the PV generation and batt levels, without having to 'play' with the WT (brakes, lowering etc) or use dump loads to protect batts.

So ..... sorry for the long waffle, interested in your experience. Have you seen/experienced similar, if you still keep an eye on micro-wind, that PV even in the UK, is displacing wind for off-gridders?

ispookie666

This might interest youhttps://youtu.be/cmgrmGOEXU4?si=w0Fnk_VSwtRxYzww

70sbudgie

Last year I did some research into domestic scale WT. One of the things I found is that they need pretty consistent wind, not gusty wind. So valleys are pretty good (whether at the top or bottom). But just the roofline of buildings, or the treeline can create turbulence that makes the wind turbine less efficient. I got the impression that this is the main reason domestic WT are mounted on such tall poles - to lift them far enough above the roofline that they are out of reach of the worst of the turbulence. 

Reed_Richards

I thought vertical axis wind turbines were better for turbulent conditions because they don't need to turn to face the wind.  I searched for an example and Google found me this: https://tesup.co.uk/products/tesup-vertical-wind-turbines-for-homes#:~:text=With the TESUP V7 energy,world's premier vertical wind turbine.

Not intended as a recommendation, I have no idea how one of these would really work in practice.

Martyn1981

Reed_Richards said:

I thought vertical axis wind turbines were better for turbulent conditions because they don't need to turn to face the wind.  I searched for an example and Google found me this: https://tesup.co.uk/products/tesup-vertical-wind-turbines-for-homes#:~:text=With the TESUP V7 energy,world's premier vertical wind turbine.

Not intended as a recommendation, I have no idea how one of these would really work in practice.

Yes, VAWT's are marketed for turbulent air, as they can cope better than a conventional HAWT. However, a VAWT can't really be more efficient than a HAWT in good conditions, since only half of the VAWT's swept area is generating power, whilst the other half is acting against it, on the return.

Obviously, any windturbine can only collect energy from the air/area hitting it, though some building mounted devices try to make use of funneling effects to increase gen, such as a SW facing roof, would direct a lot of wind over its top, to a 'cleverly' designed and positioned WT. But most of these ideas tend to be little more than marketing bumpf. Plus if a large roof mounted construction is needed, then you quickly hit costs better spent on a tall free standing HAWT.

In the case of Tesup, I have actually heard of these, as they have such a bad reputation, with power claims that are simply insane, even out by an order of magnitude or greater than the theoretical max power that their swept area could receive.*

As you mentioned before, good idea to chat on renewable, sustainable forums (sadly the GBF (green building forum) is now closing down) to get an idea about WT's. One I used to read, included a guy with several small HAWTs on his land (in France), and even showed how he was making the blades, in forms he had also made himself. Great stuff, but a true labour of love, v's the vastly simpler PV that crept into the off-grid market by the middle of the last decade. I'm sure VAWTs have a place, but most of the news articles and claims (often on funding sites) seem to be received on these forums, with a chocolate teapot conclusion.


*Pure speculation on my part, and I can't explain this, but that VAWT looks to me to be around 1m tall and 0.5m wide. Based simply on what I've seen with other VAWTs, as they are typically small. I'm surprised I couldn't spot the dimensions, maybe I'm being daft. It could be bigger, but then the price is low. Googled swept area for a 7kW HAWT, and it seems to be around 30m2.