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Comment by detaro | Hacker News Reader

Wind generators really scale with size though. Small ones rarely make sense

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.

The issue is the payback is not worth the hate from your neighbors and capital cost. at least solar panels are quiet.

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.

Hence "community energy" - you do it with your neighbours - this model has worked in Scotland before - https://www.resilience.org/stories/2019-07-16/rebel-cities-t... - here is one from earlier this year - https://www.thenational.scot/news/24993445.local-groups-bid-... - and recent changes in planning legislation mean we should be seeing more of these in England in the near future - https://communityenergyengland.org/pages/community-wind

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!

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.

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