Reinventing the Wind Turbine | Green Energy News

October 25, 2007 – Vol.12 No. 31

REINVENTING THE WIND TURBINE.

Ever bigger and ever more powerful for sure, the generating capacity of wind turbines has grown ten fold, or more, in the last decade or so. Mostly the increase in capacity can be attributed to longer blades for more swept area, as the turbine industry likes to say.

Yet there may be a limit to size. Unless the largest turbines are only placed offshore or in distant remote areas, landowners, environmentalists, and communities themselves might begin to say a more definite “no” to bigger and bigger.

What to do, what to do: Look for innovation, perhaps reinvention to keep the wind industry and the clean energy provided by the wind growing. Don’t necessarily look for big companies or government and university labs to supply the ideas. Often, as has been the case throughout history, the best ideas come from basement workshops, garages, small and lesser known companies. (That’s where to look for innovation in wind, and heck just about every other technology.)

Here’s some innovation in wind:

Though not really small, but certainly not on the tip of everyone’s tongue - American Superconductor - a Massachusetts company already in the wind turbine design and engineering business, thinks the next step will be to focus on the power generation equipment , the dynamo, if you must, to get more juice flowing from a turbine without increasing blade length or swept area. The company’s technology includes using highly efficient power generators that employ high temperature superconducting materials. As an aside, the company is developing superconducting electric drive motors for US Navy. (You may not know this, but many ships have already switched to electric drive in recent years in an effort to save fuel.)

In Japan, small wind turbine maker Zephyr makes a pretty little machine it calls the Air Dolphin Mark Zero. One of its features is its Power-Assist Function. For 10 seconds every minute, the Airdolphin uses previously- generated power to spin the rotor. According to the company, this allows the rotor to reach the cut-in point more quickly - even when there is near zero wind, allowing the unit to capture the wind effectively. If there’s enough wind during the Power-Assist period the turbine will keep running and generating electricity.

For those thinking this may be a waste of stored energy - especially during long periods when there is no wind - there’s no reason that a little solar energy couldn’t be used to kick-start the turbine. (Kickstarting or Power-Assist helps overcome inertia of the rotor, by the way.)

The Power Assist Function also prevents freezing of the rotor due to low temperatures.

In the UK, Renewable Devices makes a nice looking small, 1.5 kilowatt wind turbine it calls the Swift(tm). In its design a ring connects the tips of the rotor blades. Not only does the ring help cut noise to near zero, it helps the turbine operate in erratic, puffy winds. The ring must act as a kind of flywheel to do this. The company likes to see the turbines installed as the Swift Rooftop Wind Energy System(tm). Winds near the ground and around buildings are often puffy.

Marlec Engineering, also of the UK, makes a similar, though smaller machine, the Rutland 503. And, as noted in a recent Green Energy News story (Full Sail Ahead For Wind Energy, October 10, 2007) researcher Izosimov Evgeny, with his fledgling company WindRotor, also thinks that wind turbines would generate more electricity if the tips of the rotor blades were connected by a ring.

In Scotland there’s machine that’s been generating electricity with moving air for more than half a decade. Though not a wind turbine per se, but the Limpet oscillating water column wave energy generation device operated by Wavegen, employs a device that looks more as though it should be hanging from the wing of an airplane than generating electricity.

With Limpet, ocean waves force air into a funnel-shaped tube compressing it and forcing it through a turbine that looks like a jet engine and generates electricity. It’s powerful too for such a small device - 250 kilowatts per turbine generator. Limpet proves that devices that use the movement of air to generate significant amounts of electricity need not be many meters in diameter.

Worried about bird strikes? PacWind, a maker of vertical axis wind turbines, says that birds see their turbines as solid objects and stay away. The PacWind machines can also be used for rooftop applications and work well in puffy conditions.

There’s a wind turbine being offered through RaceCom with similar characteristics as some of PacWind’s designs. That company claims their vertical axis turbine will spin in wind speeds as low as 1.2 miles per hour. (How much electricity they generate at this speed is not stated.)

Now there’s a new and what could be a radical redesign and reinvention of the conventional wind turbine from a company calling itself Windshine Electric. The company states in a press release: “Windshine Electric’s new turbine technology is much more efficient than current windmills. Utilizing both the wind and the sun, Windshine generators have lower cut in speeds, no cut out speeds and will produce significantly more total power than current windmills. Windshine generators will produce electric power at a cost on par with current coal, oil or gas and will not need subsidies to be profitable.”

“Windshine Electric generators will be easier to manufacture, install, maintain and cost less than current windmills. All current and proposed worldwide wind farms, onshore or offshore, will benefit from this change in design.”

Further, the company’s Managing General Partner, Alan White, says “This is the next generation in wind power technology. Aircraft graduated from propellers to turbines and Windshine Electric is harnessing this proven technology to create an advance in wind/sun generated power.”

The company is planning commercial units from 1 to 6 megawatts capacity, stand alone. Self powering border watch towers, self powering cell phone towers and residential units are in development.

So far, wisely so, the company hasn’t released any photos or drawings (It doesn’t want to give away any secrets.), It purposely doesn’t yet have an operating website. White says in an email that “for visualization terms it looks like a big jet airplane engine, except more stylish. The home units look like a 6 ft telescope that is tapered.”

The company says it doesn’t want to be disruptive of the already disruptive wind industry. Their goal is is to change the industry for the better. The units will certainly be able to replace current wind turbines, but it is also working on tower caps that will be able to allow for a remove and replace change-out thus preserving much or all of the current capital expense but generate even more power.

Aside from the low cut in speed and no cut out speed, the biggest advantage will be cost. The Windshine Electric turbines will be cheaper to make and install than the massive conventional propeller type machines.

Much of innovation is keeping an open mind to possibilities as well as to interpret and improve upon the ideas of others. Wind energy is no exception.

Links:

American Superconductor
http://www.amsuper.com

Marlec Engineering
http://www.marlec.co.uk

PacWind
http://www.pacwind.net

RaceCom
http://www.racecom.com

Renewable Devices
http://www.renewabledevices.com

Zephyr Corporation
http://www.zephyreco.co.jp

Wavegen
http://www.wavegen.co.uk