Wind generation and...
 

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Wind generation and associated electrics - tell me why this is a bad idea

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 IHN
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I mean, I'm pretty sure it is a bad idea, but I'd be interested in the specifics of why.

Where we live it is pretty much always windy, and I keep thinking that some kind of wind generation would be great. I realise that a full pole-mounted turbine is just too much cost and palaver, but a building mounted one, something like 1-2kw, could, I'd hope, provide a useful addition to the existing solar panels to cover 'base-load' type stuff. And a building-mounted one like that doesn't need planning permission.

So, here comes the probably-bad-idea:

12v 1-2kw turbine -> controller -> isolator -> 12v-240v invertor -> splicing in (using a junction box) to the feed from the solar invertor into the mains

I await your, hopefully constructive, derision


 
Posted : 08/11/2022 10:32 am
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The problem with turbines attached to buildings is that the turbulence caused by the wind hitting the building 'effs up the wind flow to the turbine - so they're crap.

This is why you don't see turbines on buildings - they need clean airflow.

(This leaves aside friction with the ground, etc. and the fact that, apparently, small turbines are shite)


 
Posted : 08/11/2022 10:43 am
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^What I was going to say. You see them on yaughts as they are up on a pole in a area with no trees and building supplying a low power items.


 
Posted : 08/11/2022 10:48 am
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When I briefly looked into it before (it's also pretty windy where we are!) the savings on your electrical bill was basically balanced out by the install/maintenance cost! So not really worth it. Although with the cost of leccy going up all the time...

What [I]might[/I] be worth it could be a smaller 12v one like you get on boats etc running lights etc in an outbuilding.


 
Posted : 08/11/2022 11:50 am
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They used to sell these in B&Q but gave up. I think the issue with small turbines is that they have to spin fast to be of any use and that makes them noisy enough to be a problem.


 
Posted : 08/11/2022 11:58 am
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A solar PV inverter is more than just an inverter, it also controls the panels to get the best balance of voltage and current for the conditions. If you feed a wind turbine output to it it will become very confused and possibly damaged.


 
Posted : 08/11/2022 12:03 pm
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Vibration going through the building could create a constant background low-frequency hum.


 
Posted : 08/11/2022 12:09 pm
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I think the issue with small turbines is that they have to spin fast to be of any use and that makes them noisy enough to be a problem.
you can get vertical axis ones now which are supposed to be quieter! (and maybe look a bit nicer/less obtrusive)


 
Posted : 08/11/2022 12:12 pm
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I have toyed with the idea of making a mini wind turbine using a Dynamo hub but then what do you use it for? can you trickle charge a power bank with the ~0.5A that's going to produce?


 
Posted : 08/11/2022 12:48 pm
 IHN
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Thanks all, some interesting points

What might be worth it could be a smaller 12v one like you get on boats etc running lights etc in an outbuilding.

Yeah thought about that, but I'm not really in outbuildings enough to make that worthwhile

A solar PV inverter is more than just an inverter, it also controls the panels to get the best balance of voltage and current for the conditions. If you feed a wind turbine output to it it will become very confused and possibly damaged.

I wasn't thinking of using the solar invertor, I was going to use a separate invertor and joining into the mains alongside the feed from the solar invertor

think the issue with small turbines is that they have to spin fast to be of any use and that makes them noisy enough to be a problem.

you can get vertical axis ones now which are supposed to be quieter!

Yep, vertical ones is what I had in mind

Vibration going through the building could create a constant background low-frequency hum.

Hadn't thought of that, fair point.


 
Posted : 08/11/2022 1:06 pm
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I was going to use a separate invertor and joining into the mains alongside the feed from the solar invertor

Sorry, my mistake, I should have read your post more carefully.

You'll need to comply with the rules for exporting to grid, eg, 3.68kW installation max for G98, and automatic disconnection from grid if the grid fails, or meet the requirements for G99 etc and get approved - but I think you may know about that?

When I looked into it, nobody sold a package of small turbine and inverter, as they do for solar, which suggested to me there was no market. All the small turbines just seem to be set up for 12V. Bigger ones were expensive, and while planning permission isn't required for building mounted turbines, there are restrictions, and it was fairly obviously not going to pay for itself.


 
Posted : 08/11/2022 2:04 pm
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Wind turbine power is related to the size of blades - it is the square of the swept volume(ish).
A small turbine is barely enough to even pay for itself and maintenance.
There is a reason all the building mounted ones have stopped appearing - they ripped off walls, didn't produce enough power and generally were a poor idea.

We had two of around 3m diameter, on poles, in an empty field, at 300m altitude in the Highlands. They maybe boiled the kettle and the dining room light. And cost £000's to install and £00's a year in inspection and maintenance. They have been taken down now.


 
Posted : 08/11/2022 2:16 pm
 wbo
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Vertical ones are becoming popular with farmers near me , no side effects on cows, sheep etc.


 
Posted : 08/11/2022 2:20 pm
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As above - micro wind is generally a poor idea. Even on boats with good airflow they have fallen out of favour as solar, £/w is cheaper, quieter, more efficient and generally bettererer in most ways.

If you're wanting wind, then it really does pay to go large or go home.


 
Posted : 08/11/2022 2:21 pm
 IHN
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As above – micro wind is generally a poor idea.

But there's so much of it out there... 🙁


 
Posted : 08/11/2022 2:59 pm
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But there’s so much of it out there…

Unfortunately like most things, it's not that simple.


 
Posted : 08/11/2022 4:22 pm
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I think I read on here once long ago, about making a wind powered electricity generator out of an oil barrel cut in half but they were illegal as too efficient and the rate they spun was incredibly dangerous! I've since often momentarily entertained building a small one as an experiment but then realized I've got enough to do with my time already. Would that work though?


 
Posted : 08/11/2022 5:38 pm
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a wind powered electricity generator out of an oil barrel cut in half but they were illegal as too efficient

Ummm.... 🤔

Too efficient you say... Hmmm.


 
Posted : 08/11/2022 6:20 pm
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At which level of efficiency does efficiency become illegal ?


 
Posted : 08/11/2022 6:28 pm
 mert
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Probably "illegal" because what could possibly go wrong with a carved up oil barrel spinning at several hundred rpm in a field heath robinsoned to some generating kit? (No, they aren't efficient, at all.)

Found this though

http://theoildrum.com/node/6954


 
Posted : 08/11/2022 6:32 pm
 mert
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And FWIW, there used to be quite a few smallish (~3m) turbines round here, mostly sat next to or near a barn or stables to keep the lights on.
The only one i still see that actually registers as a wind turbine hasn't turned in maybe a decade.


 
Posted : 08/11/2022 6:38 pm
 jca
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were illegal as too efficient

Well, I guess if they break the laws of thermodynamics...


 
Posted : 08/11/2022 6:50 pm
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Yeah was a long time ago I read it! Memory might be failing me!

There is a mega load of info on youtube about them - VAWTs, although can't find any videos of dangerous oil barrel wind turbines... So here's one that appears to be made from kitchen roll and a cardboard coffee pot.


 
Posted : 08/11/2022 6:51 pm
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You need several KW @ 240v to do anything meaningful. If you want to kill a few days with a little project, just use it to charge a 12v car battery then run some 12v lighting would be my advice. In a garage or something...

Main problem re planning for onshore wind is the applications can be thrown out on the basis of just 1 objection. May well happen with a 20/30m turbine. Govt are in the midst of trying to change it but NIMBYS will be out in force.


 
Posted : 08/11/2022 8:49 pm
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Planning permission for building mounted wind turbines:

https://www.planningportal.co.uk/permission/common-projects/wind-turbines/planning-permission-building-mounted-wind-turbines

To be acceptable as permitted development a turbine must comply with Microgeneration Certification Scheme Planning Standards:

This includes a requirement that it must be installed by an MCS certified contractor.


 
Posted : 08/11/2022 9:00 pm
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I have seen an oil barrel wind turbine in action decades ago. It was used as a water pump tho not for electricity


 
Posted : 08/11/2022 9:19 pm
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a wind powered electricity generator out of an oil barrel cut in half but they were illegal as too efficient

On the same website did they also have a article on a secret food that will make you loose wait and doctor's don't want you to know, and how Northampton mum makes £1000 per day, and another article on one simple trick that burns belly fat fast?


 
Posted : 08/11/2022 9:28 pm
 colp
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and another article on one simple trick that burns belly fat fast?

Put it in an oil drum half and light it?


 
Posted : 08/11/2022 10:20 pm

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