4 ms·
Well problem in the UK is that in summer there is like a magnitude more power from PV then in winter.
by looofooo0 1y ago
Well problem in the UK is that in summer there is like a magnitude more power from PV then in winter.
- calgoo 1y agoI 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.
- Teever 1y agoI 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.
- b112 1y agoI wonder what studies may exist on this. Were they all funded by Big Wind?
- teamonkey 1y agoLaws 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.
- kragen 1y agoThe swept area of the blades scales quadratically with the blade length, not exponentially. Exponential scaling is f(x) = knˣ, not f(x) = kxⁿ. The difference between quadratic scaling and exponential scaling is earth-shatteringly enormous; this is not some minor detail. With quadratic scaling, if f(1) = 1 and f(2) = 4, then f(10) = 100. With exponential scaling, if f(1) = 1 and f(2) = 4, then f(10) = 262144, a 2600× difference. And the difference gets bigger from there on out.
- teamonkey 1y agoUnfortunately 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.
- kragen 1y agoI 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 https://news.ycombinator.com/item?id=44056971, that doesn't seem to be the case. Small rooftop windmills may actually be cheaper!
- teamonkey 1y agoThere’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.
- kragen 1y agoYes, 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.
- eldaisfish 1y agosmall 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.
- detaro 1y agoWind generators really scale with size though. Small ones rarely make sense
- kragen 1y agoIf 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-Controller-Windmill/dp/B0C2CNB1RV 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.
- lazide 1y agoThe issue is the payback is not worth the hate from your neighbors and capital cost. at least solar panels are quiet.
- kragen 1y agoIf 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.
- alex-moon 1y agoHence "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-these-community-wind-farms-in-denmark-and-scotland-are-decentralising-power-to-the-people/ 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-create-largest-community-owned-scottish-wind-farm/ 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 https://communityenergyengland.org/pages/community-wind
- pjc50 1y agoUneconomical 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.
- victorbjorklund 1y agoThey barely produce anything at all. You really need a bigger one and putting it very high up for it to generate any real power.
- butshouldyou 1y agoEvery 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.
- sgt 1y agoEventually it'll become noisy, yet provide little value.
- kragen 1y agoNo, having more power isn't a problem for solar; unlike coal or nuclear, solar can curtail production instantly and without suffering wear and tear. The problem is that in the UK in the winter there is an order of magnitude less power from PV than in the summer.
- looofooo0 1y agomagnitude less power from PV than in the summer magnitude more power from PV than in the winter That is a tautology.
- butshouldyou 1y agoHowever, the implied meaning is significant. This site is full of engineers who, if they're good, invest a lot of time into understanding the implied meaning of what's said.
- looofooo0 1y agoThere is no implied meaning, you cannot derive PV building intend from it.