I personally feel there should be more allowance for small personal wind generators in sub-urban areas. That would offset a bit at least in winter for places like the UK. Not sure what the actual laws are, but I can assume councils wont be too happy about someone putting one up on their home.
If the objective is to reduce the number of hours you're not self-sufficient for a given battery size, or reduce the size of your expensive batteries, even a couple hundred watts could make sense.
https://www.amazon.com/NINILADY-Vertical-Generator-Controlle... is a 600-watt-peak wind generator, designed for 11m/s winds, for sale in the US for US$300, presumably much cheaper in countries that aren't descending into kleptocratic tyranny. (I talked to someone who recently bought something similar for US$60. I think it was a 300-watt turbine.) It's a vertical-axis type, less than a meter in diameter. No worries about annoying the neighbors, and it'll probably do a great job of keeping your fridge running most of the time when it's cloudy.
50¢ per peak watt would be a terrible, uncompetitive price if you were a utility company considering how to build a wind farm to sell power for profit. But, if you're a homeowner seeking energy self-sufficiency because your Public Utilities Commission is trying to throw you under the bus because of regulatory capture, it's pretty affordable.
Community energy makes sense for 2,000,000-watt windmills like the ones in your first article, but not for a 600-watt rooftop windmill that's less than a meter across. The 2,000,000-watt windmill ought to cost less per watt, but it requires successfully coordinating the community to support it (cf. the note in your third link about a "de facto ban on new onshore wind projects" being lifted). And looking at https://www.canarymedia.com/articles/wind/chart-wind-turbine... it looks like over the period 02015 to 02022 the prices of big windmills consistently stayed in the range of 80¢ to 130¢ per peak watt, which is actually more than the 50¢ per peak watt of the mail-order Amazon rooftop windmill. (The rooftop windmill will probably enjoy significantly lower capacity factors, but it's clearly in the same ballpark.)
This was surprising to me, since I thought big windmills were much cheaper per watt, so I dug a bit further. The figures check out. The current https://www.bbc.com/news/articles/c80kv5d7lp7o says a £40 million (US$52 million) onshore Manx wind farm might have "up to 5 turbines", and thus up to 10 megawatts, putting the total project cost closer to US$5/Wp. https://www.eia.gov/analysis/studies/powerplants/capitalcost... from 02019 has a capital cost breakdown of a 200MW hypothetical wind project costing US$253 million, consisting of 71 2.8-MW windmills, totaling US$1265/kW (127¢/Wp). About 60% of that (80¢/Wp) is "WTG [windmill] procurement and supply". A 50MW hypothetical wind project in the next section comes in at 168¢/Wp, and a 400MW hypothetical offshore wind project in the next section is 438¢/Wp.
So it's not at all clear to me that community wind energy, or utility-scale wind energy in general, is even cheaper or more efficient than mail-order rooftop windmills. It might be more expensive!
If you have a house, you aren't going to get hate from your neighbors for a tiny turbine like this; it may not be quite as silent as solar panels, but it's pretty quiet.
Correction: according to what I found in https://news.ycombinator.com/item?id=44056971, 50¢ per peak watt would not be a terrible, uncompetitive price if you were a utility company considering how to build a wind farm. In fact, it's significantly cheaper than the prices they actually pay for big windmills.
I was under the impression that small wind generators at the scale of suburban backyards are really uneconomical and don't produce sufficient energy for anything of practical use.
small wind turbines are also horrendously unreliable because of mechanical failure. Same logic as to why pickup trucks are generally more reliable than a smart car.
Laws of physics: maximum power that can be generated is proportional to the swept area of the blades. So it scales exponentially as blade length increases.
Unfortunately I can no longer edit the post, but of course you’re right. Max generated power is proportional to (blade length)^2, therefore quadratic, not exponential.
I assumed that meant that big windmills would be much cheaper per watt than small ones, but according to what I'm finding in https://news.ycombinator.com/item?id=44056971, that doesn't seem to be the case. Small rooftop windmills may actually be cheaper!
There’s another limiting factor though, which is that power is also proportional to (wind speed)^3, and the wind is greater higher up.
Although having said that, I do believe the main reasons we don’t use them in the UK are noise and wildlife concerns. In many ways the total efficiency doesn’t matter if it’s generating enough power.
Yes, so it's puzzling that the small windmills (necessarily designed for low wind speeds) cost less per peak watt. You'd think getting more power per square meter higher up would reduce the cost per peak watt. Wind speeds are more consistent up there, too.
The wildlife concerns are completely specious. The main reason you don't use them in the UK are that the wrong sort of people have political power.
Uneconomical and the sort of thing that really annoys the neighbors. We only just got onshore wind unbanned entirely, and Reform are heavily against permitting renewables at all.
Every reply is talking about how wind doesn't make sense, how its uneconomical, or how its a nuisance. I can offer an opposing take:
My father has been using wind power in a semi-suburban area in the Uk for close to 20 years now. They have a large wind turbine now but had a much smaller one for a long time. Outside of cookie-cutter estates, there's sufficient tree and building cover that its barely visible to the neighbors. It provides most of their home power.
