Finally A Good Design!
Finally A Good Design
Review of the Helix Wind Residential Wind Turbines
Good morning!
|
I’ve been reading the rss feeds again, and one item caught my eye this morning. For me, it’s a combination of good ideas strung together, and that sort of situation is always likely to attract my attention.
A company called Helix Wind, located in San Diego, California, http://www.helixwind.com/en/ has perfected one form of the vertical axis wind turbine for small residential and commercial usage. Their product range goes from a 2,5 kW Savonius turbine application for residential and small commercial applications to a 50 kW commercial unit using a Darrieus turbine design. It’s the Savonius turbine that is interesting for us.
Helix Wind is not the first to have used the Savonius turbine concept – after all, they did not invent it (it was invented and first tested by a Finnish engineer named Sigurd J. Savonius in 1922 – thanks to Wikipedia – http://en.wikipedia.org/wiki/Savonius_wind_turbine for the research)! The concept is quite simple – two (or maybe more) cups facing in opposite directions on opposite sides of the vertical axis. The wind is caught in the open end of the cup facing into the wind and deflected around the closed end of the cup facing away from the wind. If you stylise it a little, it looks more or less like the letter S seen from above, with the rotational axis at the middle of the S.
Helix Wind took the design a little more in hand, since the straight cup design is not so efficient. They polished the design and have come up with a windfoil that is not only almost as efficient as the best horizontal axis wind turbine (the big three-bladed rotating monsters in the countryside), but also is quite interesting from a visual point of view.
Want to know how they’re put together? Well, it’s a lot simpler than the big monsters, but they’re also not so large :-) however, the interesting part is that the rotor-equivalent parts are relatively small and easy to handle. To give you an idea of how easy it is, take a look at the video below to see one unit being assembled by five people using hand tools (plus a scaffold and a forklift to unload the crate from the transport truck), and put into action in the huge Langley wind tunnel.
Not glamourous, but interesting, right?
But that’s not all the good news. First, a little more about the Helix turbine design. The rotor tip speed is about the same as wind speed (not 5-6 times wind speed as in the big HAWTs), which means that
- there is no substantial noise generation caused by wind shear off the rotor tips
- the Helix is visible to birds and bats as a solid and they will not run into the rotor
- the Helix thrives on variable direction winds and gusty conditions
In addition, the Helix can be installed in as low as 35′ (11m) overhead limits (e.g. zoning laws). They can also be used relatively close together, and there are some interesting arrangements of multiple units in the first video.
Finally, it is reported (http://cleantechnica.com/2009/08/27/biomimic-helix-wind-to-offer-financing/) that the buyers will be able to finance their wind project in the same fashion as a solar project or a new car. That’s good news, too! All in all, this is a project that exemplifies Practical Greenology, just the way we formulated it.
I LIKE it when a job comes together! (source: “The A Team” TV series) :-D
Please Note: We have no interest in any of the firms noted above. If you click on their links and buy something, all we get is the satisfaction of knowing that you took our suggestion (and that only if you tell us!). 
Thanks for lookin’ in!
Jimmy Craig
for
Sue & Craig Websites
.
