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Ivan
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« on: March 11, 2007, 01:58:15 PM » |
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Here's a nice classroom experiment - a DIY savonius wind turbine (vertical axis), that can be made up from odds and sods/waste materials. There is no reason why this could not be scaled up. It might make a fantastic power source for very low power requirement applications (eg wireless video camera sending 'aerial' footage of the school, or a PIC circuit for control or monitoring applications http://www.re-energy.ca/t-i_windbuild-1.shtmlhttp://www.re-energy.ca/t-i_windbuild-2.shtml |
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Ivan
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« Reply #1 on: March 11, 2007, 03:40:40 PM » |
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Paulh_Boats
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« Reply #2 on: March 13, 2007, 02:21:51 PM » |
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The article claims the Savonius spins in 4mph and cuts-in at 7mph. Thats a lot better than conventional turbines that need 10mph+ to generate power.
Perhaps a Savonius is better in low-wind city locations than a horizontal turbine?
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Ivan
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« Reply #3 on: March 13, 2007, 06:23:48 PM » |
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Absolutely.
Drag-based wind turbines are less efficient overall, a lot less efficient at high rpm, but they will generate small amounts of power(relative to their size) at wind speeds too low to even spin a prop-type horizontal axis wind turbine.
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PEMTEK
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« Reply #4 on: March 13, 2007, 10:26:18 PM » |
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They also work in turbulent wind coming from any direction. If you remember those crazy spinning signs many years back they worked outside shops and garages for years.
Phil
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If it aint broke, you aint trying..
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Antman
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« Reply #5 on: March 21, 2007, 10:31:09 AM » |
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So would development of VAWTs be a better proposition for urban environments? Ivan - have you any plans to sell something along these lines? It also strikes me that these might be better suited to moutning on the wall of the house - if that was the only way.... Duck and run  Antman |
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20 x 47mm, 172 litre cylinder, Heat Dump, 15 x Sanyo HIT-H250E, SB4000TL DIY Solar System Support at: http://homepage.ntlworld.com/anthony.cooper267/index.htmlAll support is wholly voluntary and free of charge. I'm not employed by Navitron and have a full-time job so responses may not be same-day |
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Ivan
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« Reply #6 on: March 22, 2007, 02:34:23 PM » |
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Yes, definitely more suitable in urban environments. The drawback is that they are very large for small amounts of produced power. You are likely to achieve only 30-100W, but of course, if you can get this most of the time, it will make a significant contribution.
House-mounting would suffer the usual problems - vibration, noise-conduction through structure, and of course, with large size, there would be considerable wind-resistance in windy weather to contend with. I did see a suggestion of roof apex covered with 20 or so 35w turbines as a potential option, though! Imagine the planners' view of that!
Ivan
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philowen
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« Reply #7 on: July 10, 2007, 03:35:42 AM » |
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Have a look at Pacwind's Delta - series turbines (2 and 10 kW) ( www.pacwind.net). They are looking to enter the UK market, but haven't found a suitable inverter yet. Phil |
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Paulh_Boats
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« Reply #8 on: July 10, 2007, 11:30:47 AM » |
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• Completely silent
• Completely stable
• Useable power in 3+ mph winds
• Safe in winds up to 100+ mph
• Bird friendly
• Environmentally friendly
• Maintenance Free
• Simple to install
• Built to last a lifetime
• Stackable
• Fully scalable
They claim 5db noise at 5ft, sounds too good to be true! When are you stocking them Ivan?
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martin
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« Reply #9 on: July 10, 2007, 12:33:57 PM » |
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my "teapot detector" is flashing warning lights...........don't care how good the blessed things actually are, they certainly won't work in the positions shown on the website! - that's roof mounting of the very worst sort!  ......which says to me that if they're that naive, they're probably pretty rubbish at designing turbines too! "completely silent"........yeah,right! |
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« Last Edit: July 10, 2007, 12:41:14 PM by martin »
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Unpaid volunteer administrator and moderator (not employed by Navitron) - Views expressed are my own - curmudgeonly babyboomer! - http://www.farmco.co.uk |
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insolare
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« Reply #10 on: July 10, 2007, 01:19:16 PM » |
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But isn't that the beauty of VAWTs that they will work in turbulent air....urban areas, etc?
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martin
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« Reply #11 on: July 10, 2007, 01:28:08 PM » |
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their site is full of disclaimers - they suggest that they're mostly best in "medium/high" winds, and even their "low wind" model will still need a hefty blow to get it producing much worthwhile power, which I just don't think exists down near ground level in urban areas - even if they are better in turbulent conditions, the windspeed is going to be very low! I must admit their "style" doesn't recommend them to me - all flash website, celebs and investments, lots of talk of tax incentives etc, and the compliance of all the bits.........seen websites like that before! |
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Unpaid volunteer administrator and moderator (not employed by Navitron) - Views expressed are my own - curmudgeonly babyboomer! - http://www.farmco.co.uk |
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Ivan
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« Reply #12 on: July 10, 2007, 01:45:53 PM » |
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I share Martin's impression, from the website. The picture of the 10kW machine shows a turbine that definitely will not produce 10kW - I guess it is a smaller scale prototype.
I do like vertical axis wind turbines, and this is a simple, effective design, but you won't get performance in low wind speed. Yes, they will suit turbulent air better, but that's not enough to make up for low wind speeds. We're certainly looking for vertical wind turbines, but we really want to be able to offer something that is good value for money.
Ivan
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rhys
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« Reply #14 on: August 13, 2007, 07:34:43 AM » |
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FWIW I went to see the Quiet Revolution VAWT a few weeks ago, near Hungerford. It was indeed very quiet . Couldn't hear it above the background wind noise and traffic noise. Normal conversation standing underneath it, a a few feet away. They are interesting machines. The theory is that because they do NOT self start they can pick up usefull energy at low wind speeds. All to do with the computer software controlling them, from an wind speed indicator, which detects useful wind speed before they start up.
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