Is a wind turbine suitable for my needs?

QrizB

Martyn1981 said:

*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.

Blades are 490mm dia x 790mm tall, per the diagram 2m30s into this video:

https://youtu.be/3o2UtrgIOf4?t=153

Google's AI-generated summary of the video:

TESUP wind turbines are a scam. The company claims that their turbines can generate 7kW of power, but this is impossible based on the laws of physics. The turbines are also very inefficient and only produce a fraction of the power they claim. There are many negative reviews of TESUP turbines online, and the company has been accused of having problems with delivery and returns.

So no, I won't be buying a TESUP product.

Martyn1981

Thanks QrizB, and I see that that image has 'Atlas' written on it, another name with an 'interesting' reputation.

Perhaps at 10m by 5m (the size of a house) it would work well, and I mean that seriously, but of course the material cost would be far higher if all 3 dimensions are increased by ~10fold. 


PS. You say no, but perhaps Mrs Doyle could persuade you, ah go on!

QrizB

Plugging those 460x790 dimensions into https://www.omnicalculator.com/ecology/wind-turbine suggests an output of ... 57 watts at 10m/s wind speed (22mph, towards the top of Beaufort force 5). Yes, fifty-seven watts.

The claimed output is two orders of magnitude more than an owner is likely to see.

(What if you increase the wind speed? You eventually get to 7kW at 50m/s of wind, 112mph, a Category 3 hurricane.)

QrizB

OP I see you had a thread about ground-mounted solar a little while ago:

https://forums.moneysavingexpert.com/discussion/6423390/ground-mounted-solar-panels-and-assorted-questions

Did you take your enquiries any further at that time?

You've also had various threads looking at electric heating options. Did those help you at all?

Reed_Richards

QrizB said:

Google's AI-generated summary of the video:

TESUP wind turbines are a scam...... 

It's a pity that Google's AI doesn't talk to Google Search and get it to reduce the search rankings for scam products.  

Martyn1981

Thought I might post this vid about small scale wind turbines, and the hopes that someone can crack the issues for small, domestic locations.

It's mainly about VAWTs, and whilst it sets out the main disadvantages and lower efficiency problems that VAWTs face, it explores the possibilities.

I think it is actually quite positive, but whether or not the problems can be overcome, and economically, I don't know. But at least the idea isn't completely dead. [But just to be clear, before anyone watches the vid, this isn't a solution today, if you are looking to get wind, PV etc .... it's more about future potential.]

How We Solved The Home Wind Turbine Problem

Whenever I cover wind turbines many of you ask about what’s available for home applications. At the moment, I’ve got both good news and bad news. The bad news is that the current market for residential wind is…less than great. The good news? We have a lot of new innovations that look to improve it. The team behind the U.S.-based startup Harmony Turbines is hoping to popularize wind energy for the masses and allow them to have their iPhone moment. Plus, if you remember our video on Aeromine’s rooftop models from last year, we have an update on how its “motionless” design is progressing out in the real world. But of course, these are far and away from the only companies working on bringing wind power generation to our backyards. Residential wind has to have its moment someday, but when? Or should I say, “but wind?”

Exiled_Tyke

Martyn1981 said:

Thought I might post this vid about small scale wind turbines, and the hopes that someone can crack the issues for small, domestic locations.

It's mainly about VAWTs, and whilst it sets out the main disadvantages and lower efficiency problems that VAWTs face, it explores the possibilities.

I think it is actually quite positive, but whether or not the problems can be overcome, and economically, I don't know. But at least the idea isn't completely dead. [But just to be clear, before anyone watches the vid, this isn't a solution today, if you are looking to get wind, PV etc .... it's more about future potential.]

How We Solved The Home Wind Turbine Problem

Whenever I cover wind turbines many of you ask about what’s available for home applications. At the moment, I’ve got both good news and bad news. The bad news is that the current market for residential wind is…less than great. The good news? We have a lot of new innovations that look to improve it. The team behind the U.S.-based startup Harmony Turbines is hoping to popularize wind energy for the masses and allow them to have their iPhone moment. Plus, if you remember our video on Aeromine’s rooftop models from last year, we have an update on how its “motionless” design is progressing out in the real world. But of course, these are far and away from the only companies working on bringing wind power generation to our backyards. Residential wind has to have its moment someday, but when? Or should I say, “but wind?”

The thing that gives me hope with this is comparing to PV.   I remember for years that the belief was that PV would never be viable in gloomy UK and domestic PV isn't worth thinking about.  So may be one of these innovations may do it after all.   We live in hope. 

zeupater

Hi

Whatever the efficiency of the turbine design there's a theoretical limit to the power available to harvest ...

As a quick rule of thumb you could work on 5W per sqm of swept area at 2m/s (~4.5mph), so at 4m/s (~9mph) it would be 40W (8x5), at 8m/s (~18mph) 320W (8x40), 16m/s (~36mph) 2560W (320x8) with wind speeds much above this normally resulting in some type of protective action (braking/closing/furling etc) .... 

... the next consideration is the location ... if you're in a low wind area then whatever comes next is practically irrelevant as no/little wind = no power ...

... there's then the efficiency of the turbine itself which likely ranges from 10% to 50%, which in itself is subject to the   application of the Betz limit (max ~59% of the theoretical power), and this is before considering the effect of cut in/out speeds ...

... Ah, then there's the realisation that everything you've just calculated depends of laminar air flow with the really big issue of any turbulent airflow resulting from any obstruction within a considerable distance from the turbine site causing a major reduction in apparent efficiencies .... although VAWTs claim to cope with turbulence better than HAWTs, there's the effects of practically halving the swept area and energy losses from always rotating some collecting area against the wind to consider .... 

Finally, there's the efficiency losses related to cables/inverters etc to consider or the electrons are practically useless ...  

All confusing, but the best place to start is looking at the rule of thumb element to just see what the theoretical power limit is at whatever wind speed you like, then multiply that by 0.59 (Betz) before scaling up the swept area to whatever the manufacturer specs claim ... this just gives a feeling as to whether the specs are anywhere near realistic ....

HTH - Z

QrizB

Now then @zeupdater don't go bringing physics back into this! The Power of Positive Thinking will make small-scale wind work even if thermodynamics disagrees

Reed_Richards

If we are dealing with figures, I found a figure for solar panels that you get an average of 975 kWh per m2 per year.  What's the equivalent for a wind turbine?  If you could achieve 40 W per m2 of swept area on average that would be 350 kWh (per m2 per year).  That doesn't seem too terrible by comparison, particularly if you factor in that electricity you use is worth about twice what electricity you export is.

The problem is that solar panels are inexpensive flat things that you can lay on your roof in a tile pattern and wind turbines, as they stand at present, are not.  Could that ever change?  Not if you stick to the windmill type but could there be alternatives?