My opinion now is that smaller shroud or funnel ratios of around 3:1 MAY BE the best option – although less efficient than an unshrouded rotor, the shroud helps to maintain a higher windspeed and keep the turbine from constantly stalling and struggling to start in your average 2-4m/s urban windspeeds. This configuration may allow for a smaller quieter rotor and a more stable performance in turbulence.

In terms of architecture, the funnel system i built would have ripped the roof off in a gale. Not very feasible in this respect. And no, they are not that pretty either.

Hope some of this helps, i can clarify further if you wish.

p.s

I also have yet to see a micro turbine design that ticks all the boxes – the newer darrius type VAWTs (eg. the ‘Turby’) are definetly my favorites but the prices are astronomical. The next 2 years we should see conclusive trials that show if these types are better in urban winds than the old propellor HAWTs. Voting ‘no confidence’ on the Windcube until they print some actual data.

Will

I’ve been following this conversation and I was sorry to see your last comment – I think. Can you explain the results of your research in simpler terms? What is your conclusion about the shrouded wind generator at this point as an option to make small-scale wind generation at lower elevations more feasible? Although the scale of the Wind Cube has potential for urban wind production (I am in NYC and have recently met the owner of the company), and although we all have doubts about the efficiencies that are being touted, the shroud interests me for conditions that don’t allow achieving the most optimal wind solutions, as in residential applications.

As an architect, I have an influential role on my client’s interest in alternative energy generation. I have yet to find a small-scale wind generation system that I am confident discussing with my clients. And these are coastal areas of the northeast where average wind speed should, someday, be used to great effect.

(As an aside, all shroud designs that I’ve seen to date have issues from a strictly aesthetic consideration. As an architect – and product designer – this concerns me.)

Thanks for all your information to date.

Since Windcube are claiming efficiencies over 100%, I cant wait to see their actual performance data.

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Think About It: “?”

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Again, I repeat, wind turbines would work if they weren’t so expensive. Its price , tariff, installation and ‘tax’? That stops them being worthwhile.

Aside from that, I will probably put some wind powered generators on my radio tower in the future, knowing that they will not be as efficient as they could be, but not caring as long as I don’t have to pay the “Obama Wind Tax” that will be passed in the near future.

For this trouble it would produce 2,000 kWhours a year, or $200 worth of electricity/year, while just 5 per cent interest on that investment costs $300 a year, without maintenance or depreciation and repairs. Not a good deal, and a waste of taxpayer dollars for the rebates tossed into this sinkhole!

The Wind Cube people claim 160,000 kWhours per year with their much smaller-looking horizontal propeller. Although I know vertical turbines produce only about half the power of horizontal ones, and I grant that the shroud can concentrate the wind somewhat, that output figure appears to be way out of line.

Moreover, how do you get that wind cube down from the roof when a hurricane or just a regular storm approaches and you don’t want it to take your roof down together with the wind cube anchored to it? Why do some of the wind cube pictures show it mounted on free-standing pillars despite the claim it goes on rooftops?

Also, the common complaint that horizontal-axis wind generators can set up vibrations that annoy neighbors and give them headaches does not seem to make wind cubes suitable for urban environments.

Sorry, but with the vagueness of the info offered about it, that wind cube looks at this time more like a hot-air cube.

Demano

I’d often thought of trying to build a small scale shrouded generator but in my years (74) I have witnessed quite a few incidences of something called straight line winds and hurricanes (south of Houston, TX USA. I don’t think these things would hold up very well because their moorings are inherently weakened so that they can turn in the wind.

My passion of late is to build a motor using a truck air ride cylinder powered by butane or pentane injected through a solar water heated area to provide up to 120 lbs. I think I could drive a large flywheel and pump hydraulic fluid or water for storage. Some of these cylinders can lift up to 100,000 lbs. at 125 lbs. pressure. I could use some tech. help or ideas. The last hurricane slowed my progress on this.

True, 50% of this industry problem is storage device. we are working on Fly Wheel-Electro-Mechanical battery device. Plenty of challenges. We hope to achieve breakthrough later if not sooner. Anybody interested or involved in this, do write.