Vertical Wind Generators to supplement PV Solar on Cloudy Days - Page 1
Forum section: electronics / general

author: DerekG
author_rank: Frequent Contributor
timestamp: March 27, 2018, 02:24:37 am
content: I live on the rural coastline next to the sea.I think some of my neighbours may not like largish regular wind turbines on my property, however I believe no-one will object to several small vertical wind generators (turbines). My neighbours are not super close.The property gets plenty of wind, particularly in the rainy season (I'm in the tropics) when the PVs don't do so well due to heavy cloud cover.I'm wondering if anyone has had any experience with these lantern style wind generators? I'm looking to install 2 to 4 of them to supplement the existing 5KW PV array in poor weather.https://www.ebay.com.au/itm/AU-400W-12V-24V-Lantern-5-Blades-Vertical-Axis-Wind-Turbine-Generator-Controller/263565284566?hash=item3d5db714d6:m:mbX4cwR6KTf-Mk9xnRoW1BgAny other wind generator suggestions are most welcome - particularly if they are of the vertical design.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: March 27, 2018, 03:21:47 am
content: Wow Norfolk Island, must be nice.surely on a small scale it would be more effective to go solar with a battery, plus either a diesel or mains backup.Years ago they installed four vertical turbines on top of Hobart Council building. I think the quality of the install was similar to solar roadways.One fell off from about 6 stories in a storm.I doubt these ones produce any energy, and I can't even remember them spinning for a long while.they do look nice when they spin though.http://www.abc.net.au/news/2011-06-06/replacements-for-marine-board-wind-turbines/2748244

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: March 27, 2018, 03:40:01 pm
content: Our local environment agency building has quite a large one. It only produced 5kW in its prime, and these days it's seldom working. Last time I was there, the blades were off.

author: fourtytwo42
author_rank: Super Contributor
timestamp: March 28, 2018, 06:16:38 pm
content: I don't have experience of VAWTS but I have of HAWTS and what worries me about your fleabay link is there is no product specification whatever other than an imaginary power and voltage. Where is the curve for power vs windspeed ? none........ Personally I would not touch such a product with a bargepole as I would be sure to be dissapointed.

author: DerekG
author_rank: Frequent Contributor
timestamp: March 31, 2018, 06:52:36 pm
content: I would like to thank all the posters above. Your input & suggestions are much appreciated.

author: fourtytwo42
author_rank: Super Contributor
timestamp: April 01, 2018, 10:52:18 am
content: I don't know how much you know about wind turbines but it's certainly a case of research before you buy, there are an awfull lot of crap products out there! The most important things you need to know is they have a cut in speed, that is a windspeed below which they do nothing as well as a power curve that indicates what they will do for rising windspeeds, many crap ones produce no usefull output in anything less than a hurricane. The other thing you need to know is all turbines will only operate properly in laminar flow, the dont like turbulent flow, so height above ground is a must and avoidance of any obstructions is another. I would get yourself a small battery charging one second hand to experiment, living on the coast you should have plenty of wind but it may take a while to find a good site and enough height to get it working properly. I had to give up on that one and go solar instead! My plot is not large enough nor was I allowed a high enough pole (planning restrictions) to get out of the turbulance.

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: April 01, 2018, 01:18:54 pm
content: True, and that's why Size Matters in wind turbines. A mast at least 200-300ft high is needed in most places to achieve laminar flow, and if you're putting up a mast that tall then there's hardly any point in putting a 3ft rotor atop it.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 10, 2018, 01:29:33 pm
content: I looked into wind turbines and what I found was a lot of wishful thinking when it came to the specifications, specifically wind speed and electrical energy output. From wat I can see this industry is unregulated and there is no independent testing of wind generators other than by people who purchase them and are disappointed with the energy production values.Expect to find like I did outrageous energy production claims for wind. You might be better of getting a natural gas generator for cloudy days.

author: jolshefsky
author_rank: Regular Contributor
timestamp: April 10, 2018, 01:48:18 pm
content: I play around with vertical-axle wind turbines (VAWTs) now and then. They will always perform worse than horizontal-axle, but they are also simpler.One property is that the blade tip of a VAWT is never more than about 80% of the wind speed whereas a HAWT can spin to self-destruction in even modest wind. The other advantage is that a VAWT can collect wind from any direction whereas a HAWT needs to be pointed at the wind (meaning the electronics are connected by a ring of contacts and brushes). The VAWT has a very low starting torque; running torque is much higher.My wild guess is that one about the size of an oil barrel could generate 100-200 watts in strong winds or more (about 20 knots).I'd build a little DIY type and see how it does. I have a little one from a project I did (about 30cm tall; 20cm dia.) that I plan to adapt to slowly drive a rotating compost bin. I figure that one could get about 10 watts of power.

author: jonovid
author_rank: Super Contributor
timestamp: April 10, 2018, 02:11:49 pm
content: here is a roof-top wind turbine design. its more a school project idea.it uses high torque not r.p.m. a slow moving rotary sail. see

author: DougSpindler
author_rank: Super Contributor
timestamp: April 10, 2018, 03:05:37 pm
content: Quote from: jolshefsky on April 10, 2018, 01:48:18 pmThanks for sharing.Amazing at how little energy a wind turbine produces.Prices for a 250 watt were around $3,000 if I remember correctly. I think I calculated if there was enough wind for 12 hours a day produce full output it would take 18 years to produce enough electricity to pay for itself based on my power companies rates. And I think the life of the wind generator is only 15 years.

author: Marco
author_rank: Super Contributor
timestamp: April 10, 2018, 03:56:28 pm
content: Interesting for a DIY art project, less so for generating enough useful power to earn back the investment.

author: Dubbie
author_rank: Unknown
timestamp: April 10, 2018, 06:35:44 pm
content: Yes, small turbines have a lot against them. Basic math will bear that out. A very good turbine is only around 30-40% efficient. The area swept by the blades determines your power. Because there is a square relationship between the radius and the blade length, the area numbers that make large turbines worthwhile do not apply to your small one.In my opinion a much more productive option is just buying more solar panels and back feeding the grid in times of excess generation. If you are philosophically opposed to that, then buy an electric vehicle and charge it with your excess capacity.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 10, 2018, 07:00:53 pm
content: Quote from: Dubbie on April 10, 2018, 06:35:44 pmI came to the exact same conslusion. Not sure where you are, but out local power compnay is paying $0.47 for every kWhr customers and on some days $0.85 kWhr.

author: Kleinstein
author_rank: Super Contributor
timestamp: April 11, 2018, 06:20:47 pm
content: How well wind turbines perform depends on the location. The expected wind also determines the size of the blades in relation to the generator, as the power goes up very fast with higher wind speed. A coastal location is at least promising for wind.Small wind power usually can not compete with the grid, but it might compete with a diesel powered or similar generator, if there is already some buffer for solar. It may be still tricky to get 100% reliable power even though combining two sources makes longer times of low production less likely. Just more solar can be tricky in some places as it would need much more storage.There are generator for use on boats, that might be suitable, though I don't know the prices.They would still need a kind of tower, as the blades can be dangerous if you come to close.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 12, 2018, 09:45:41 am
content: Solar and wind have proven to be unreliable. Last yer Germany and England with all of the people who have installed solar burned more coal last year than ever before. Turns out with deactiving nuclear power plants and windless/cloudy days the only way they could provide electricty for citizens was to burn more coal.

author: fourtytwo42
author_rank: Super Contributor
timestamp: April 12, 2018, 10:18:44 am
content: Quote from: DougSpindler on April 12, 2018, 09:45:41 amTry this sitehttp://www.gridwatch.templar.co.uk/I think you will find the UK burns mostly gas in thermal stations, not coal. Of course we are beginning to have a gas sourcing issues as the north sea runs out but we already have an established LNG tanker supply from several places around the world to supliment it. Thank god we are not at the mercy of a certain eastern european country.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 12, 2018, 04:30:26 pm
content: Quote from: fourtytwo42 on April 12, 2018, 10:18:44 amDon’t you have standby collar fired powerplants? When there’s no sun/wind for several days it was my understanding England and Germany both used coal. I know both countries have or had a lot of coal.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 22, 2018, 08:43:53 pm
content: Germany still has quite some coal fired plants. However the forecasts are not that bad and thus not that many coal fired pants running idle. There are some plants standing still as a reserve, just in case, especially if France needs extra electricity (e.g. cold winter or hot summer).AFAIK Britain has not that much coal anymore. At least there are essentially no more coal mines. They to a large part switched to gas - but gas supply from the north see are already going down.