Wind Power vs. Solar

Martyn1981

Reed_Richards said:

However a co-operative array of small turbines along the ridge of your roof seems to be an idea that only exists in my head so far.
   

This has already be done, or I think already failed, not sure. The idea was to mount (and now this gets confusing) a whole row of VAWTs, horizontally. They would be inside a structure that replaces the ridge tile, so picture a row of fat ridge tiles with slots, and inside would be a, for want of a better description, very wide, but short water mill wheel, does that make sense?

Now, their swept area would be very small, let's guess at 150mm* high opening, by 5m total across a roof, so about 0.75m2, or equal to roughly the area of a 1m wide WT (.5m blades), but the idea is that they would benefit from most of the roof area, as the wind is pushed up it to the WT, massively increasing the volume of air it receives, just like your dam/hydro analogy.

I've not heard anything since (possibly 10yrs ago), so I assume that they haven't been succesful, but you never know. I do however recall the word 'Unicorn' being used on Navitron to discuss them.

*Working from memory, but they could have been much bigger/intrusive, and of course, as we PV'ers know, if you alter the height of the house, or exceed the ridge tile, then you'll need planning permission.

Reed_Richards

Martyn1981 said;
Have to say I'm a bit confused by that. Are you suggesting that they work co-operatively, as I understood it to be the exact opposite, and that they have to be placed apart to stop the turbulence from one affecting another, and also because they will reduce the power of the wind behind them.

What I am saying is that wind turbines are glorified windmills; windmills are standalone entities.  Because wind turbines have to be spaced far apart you waste a huge amount of the potential wind energy and will continue to do so until someone works out how to make wind turbines that can be closely spaced.  I think in order to do that the individual turbines would have to work cooperatively but AFAIK nobody has even begun to work out how that might be achieved.  

mnbvcxz

Doing it properly an evance (now britwind) r9000 5kw wind turbine on a 30m mast, some way from the house for planning and noise.  Around £20-£30,000. 

One of the few models not to end in tears it should be a fairly mature design by now. You could reasonably expect say 12000kwh a year.

So thats about £1400 in retail electricity. It will come in gluts on windy nights so you will probably not use it all. But lets be generous and say you do. Servicing is £500 a year. Once its out of warranty you could push that to every other year but with parts its still going to end up at least £500 a year running costs.

So that is £900 a year best case benefit. Assuming it actually lasts its 20 year projected lifespan you get about £18000 of benefit? So you only lose £2-£12,000 (plus the loss of the return on the capital you gave up). Why bother?


This is why you don't see many new small wind turbines these days. Ten years ago when you could get 40p a kw subsidy they could earn about 7% after loss of capital over 20 years. If it went well, it often didn't, they broke down and the company closed down.

So when you spend £500 on planning permission and get turned down try and see it as a blessing...

On the other hand if you can get permission for a turbine costing over a million pounds, on land, then you basically become an instant millionaire. Very lucrative. Huge economies of scale. Almost impossible to get, rumor has it one farmer put up one without permmission and by the time he dragged the planning appeals out for several years he was well in profit... 

£30,000 of solar nearly always outperforms £30,000 of small wind wind turbine at less risk too. You lose money but less money.


Its entirely possible more Octopus agile tarrifs will appear like economy 7 but cheaper when the wind blows and you can then benefit without actually having to have the wind turbine.


If people wish a timewasting diversion here is the sad story of a rather dubious roof wind turbine inventor...

https://youtu.be/a5yLb6e0oBU?t=149

Here is a daily mail journalist rather mugging to the crowd putting a wind turbine on his chicken coup. Rather silly but part of me admires the fact he got something so stupid to work at all. Its hard to should at the screen, "just buy a cheap solar panel".

https://www.thisismoney.co.uk/money/bills/article-8900247/Getting-wind-power-garden-really-isnt-breeze.html
 

Martyn1981

Reed_Richards said:

Martyn1981 said;
Have to say I'm a bit confused by that. Are you suggesting that they work co-operatively, as I understood it to be the exact opposite, and that they have to be placed apart to stop the turbulence from one affecting another, and also because they will reduce the power of the wind behind them.

What I am saying is that wind turbines are glorified windmills; windmills are standalone entities.  Because wind turbines have to be spaced far apart you waste a huge amount of the potential wind energy and will continue to do so until someone works out how to make wind turbines that can be closely spaced.  I think in order to do that the individual turbines would have to work cooperatively but AFAIK nobody has even begun to work out how that might be achieved.  

Again, I think it's the opposite. There is a huge amount of science and planning that goes into the positioning of WT's, within a wind farm, so that as many as possible can be placed. The reason they are so far apart is that they have a detrimental effect on each other, not a positive one. It's also why when the WT ratings are sometimes increased, prior to rollout (for offshore) that you tend to see similar overall power totals as the number of WT's are reduced.

It's kinda similar to spacing out rows of PV panels ina PV farm, so that they are not in the shade of others.

ABrass

Reed_Richards said:

Martyn1981 said;
Have to say I'm a bit confused by that. Are you suggesting that they work co-operatively, as I understood it to be the exact opposite, and that they have to be placed apart to stop the turbulence from one affecting another, and also because they will reduce the power of the wind behind them.

What I am saying is that wind turbines are glorified windmills; windmills are standalone entities.  Because wind turbines have to be spaced far apart you waste a huge amount of the potential wind energy and will continue to do so until someone works out how to make wind turbines that can be closely spaced.  I think in order to do that the individual turbines would have to work cooperatively but AFAIK nobody has even begun to work out how that might be achieved.  

If you were trying to harvest the most possible power from a set amount of land, yes, maybe. But by clustering them you reduce the amount of power each can deliver, which means the cost effectiveness of both drops. Since they're pretty expensive that can bring them below the point where they're value for money. In practice it's much better value spreading a smaller number over a wider area than craning them in close.

As for a way to make them work cooperatively, to generate more power than individually, that's basically magic. Wind turbines need stable streams of air, but makes the air behind it messy as a result of hitting the turbine blades.

I wish they did make sense, but they don't.

Martyn1981

mnbvcxz said:

£30,000 of solar nearly always outperforms £30,000 of small wind wind turbine at less risk too. You lose money but less money.

Not sure why you'd say that. Small and large PPA solar systems have been profitable now for 5yrs+.

If you do the maths yourself, then for £30k you'd be able to install 30kWp+, and cover all CAPEX and OPEX costs over its 30+yrs of generation. That's to say a ground mount would cost less CAPEX, but have higher OPEX, and vice versa for a roof mount.

From 30kWp, you'd expect ~30,000kWh pa, and I'd suggest a value of 10p/kWh, averaging out higher import prices that are displaced, and lower export prices received. So £3k pa, or to put it another way, costs covered/repaid in 10yrs, with another 20-40yrs 'free'.

Reed_Richards

ABrass said:

If you were trying to harvest the most possible power from a set amount of land, yes, maybe. 

But with a domestic wind "turbine" you are trying to harvest the most possible power from a set amount of land.

ABrass said:

As for a way to make them work cooperatively, to generate more power than individually, that's basically magic. Wind turbines need stable streams of air, but makes the air behind it messy as a result of hitting the turbine blades.

So don't use turbines, use some other form of wind power extractor.  If "bobbers" can extract power from waves that goes to show that you don't have to have the circular motion of a turbine, that's just the easy option.  

ABrass

Reed_Richards said:

ABrass said:

If you were trying to harvest the most possible power from a set amount of land, yes, maybe. 

But with a domestic wind "turbine" you are trying to harvest the most possible power from a set amount of land.

ABrass said:

As for a way to make them work cooperatively, to generate more power than individually, that's basically magic. Wind turbines need stable streams of air, but makes the air behind it messy as a result of hitting the turbine blades.

So don't use turbines, use some other form of wind power extractor.  If "bobbers" can extract power from waves that goes to show that you don't have to have the circular motion of a turbine, that's just the easy option.  

If you're not worried about breaking even then grab a couple of domestic scale turbines and you'll get some power out of them. You'll lose money compared to buying from the grid but you can extract power.

No? Then perhaps you're not trying to extract the most power possible from a set amount of land.

Martyn1981

Reed_Richards said:

ABrass said:

If you were trying to harvest the most possible power from a set amount of land, yes, maybe. 

But with a domestic wind "turbine" you are trying to harvest the most possible power from a set amount of land.

ABrass said:

As for a way to make them work cooperatively, to generate more power than individually, that's basically magic. Wind turbines need stable streams of air, but makes the air behind it messy as a result of hitting the turbine blades.

So don't use turbines, use some other form of wind power extractor.  If "bobbers" can extract power from waves that goes to show that you don't have to have the circular motion of a turbine, that's just the easy option.  

Point 1. That's not true, or to be more generous, you are spinning, by deliberately ignoring half the problem:

But with a domestic wind "turbine" you are trying to harvest the most possible power from a set amount of land ........ economically!

Let's say you have 10 WT's operating at their most efficient on the land, generating 100 units of energy. Then you decide you want to maximise energy, not economic viability, and add another 10 WT's. Now all 20 operate at 60% of their potential, because they are competing for the wind, and disturbing/disrupting generation behind them, so in total they generate 120 units of energy. Yes you have just increased energy by 20%, but increased your WT costs by 100%, and reduced their economic viability by 40%. If the generation is not economic, then it won't happen, and your solution will result in zero generation.

Perhaps you missed this the first time round when ABrass explained it:

If you were trying to harvest the most possible power from a set amount of land, yes, maybe. But by clustering them you reduce the amount of power each can deliver, which means the cost effectiveness of both drops. Since they're pretty expensive that can bring them below the point where they're value for money. In practice it's much better value spreading a smaller number over a wider area than craning them in close.

Point 2. Your solution, that you seem to think is so easy, reminds me of your earlier claims that engineers and scientists have not researched how to maximise generation (economically). I suspect that it is not they that are at fault, but yourself, and that your claims are wholly false and imagineered. If I'm wrong, then fine, provide the data and analysis that your solution will work, and work better than 'the experts' solution.


Had I realised that the destination was Crazy Town, I would have gotten off this train sooner.

Reed_Richards

"The train now arriving at Crazy Town...."  Here is an example of a "bladeless aerogenerator".  https://www.whatsorb.com/energy/vortex-bladeless-providing-wind-energy-without-blades?gclid=EAIaIQobChMI7ouo1M-p8AIV5OjtCh2cugJeEAAYAyAAEgL0FfD_BwE .  Now I have no idea if these are real and, if so, if they are economically manufacturable but in the picture they are very close-packed. 

If you only think in terms of wind turbines then of course what you say about packing them close together is correct because wind turbines create turbulent air and turbulent air won't drive a wind turbine.  But the idea that the only form of aerogenerator is a wind turbine is challenged in the above link.  So if I'm crazy at least I'm not alone.