Small wind turbines put to the test (2)

The Oil Drum runs an extended and rewritten version of our 2009 article on small wind turbines – including additional tests results from the UK.

“Two real-world tests performed in the Netherlands and in the UK confirm our earlier analysis that small wind turbines are a fundamentally flawed technology. Their financial payback time is much longer than their life expectancy, and in urban areas, some poorly placed wind turbines will not even deliver as much energy as needed to operate them (let alone energy needed to produce them). Given their long payback period relative to their life expectancy, most small wind turbines are net energy consumers rather than net energy producers.”

Windmills and Wind Motors – How to Build and Run Them (1910)

windmills DIY

“I have endeavoured in the following pages not only to interest the practical amateur in a branch of mechanics unfortunately much neglected, but also to present a series of practical original designs that should prove useful to every reader from the youngest to the most advanced.”

Chapter 1 : windmill evolution
Chapter 2 : a small working model windmill
Chapter 3 : a small American type windmill
Chapter 4 : a small working windmill
Chapter 5 : a practical working windmill
Chapter 6 : production of electricity by wind power

Windmills and wind motors – how to build and run them (1910).

Related:

TimberTower: a High-Tech Wind Turbine, Made from Trees

Timbertower Our article on industrial windmills appeared on The Oil Drum and, as could be expected, this generated many interesting comments. One in particular was made by a reader named “anyone“, who sent in a link about a high-tech wind turbine placed on a tower made entirely of wood.

So while we suggested to redesign traditional windmills by using modern, high-tech materials, the German company TimberTower proposes the opposite: redesign modern wind turbines by using traditional, low-tech materials.

Large wind turbines are usually made of steel, and while they definitely deliver more energy over their lifetime than it takes to produce them (contrary to small wind turbines), using no energy at all would of course be even better – and cheaper.

Wood is easier to transport (the TimberTower is manufactured out of glued laminated timber panels which are assembled on-site), doesn’t need to be mined, has no corrosion issues (think of offshore turbines), and it captures carbon. And while trees bend in strong winds, they usually don’t break.

Using a timber tower for a 100 metre high wind turbine can save approximately 300 tons of sheet steel, writes the company at their website. One “TimberTower” also ties up approximately 400 tons of CO2. They say they can build them as high as 200 metres. Serial production should start in 2010. More:  TimberTower. Related: wooden pipelines, wooden bridges.

Kite Power

Kitegen 1

Italian company Kite Gen is building a full-scale 3 megawatt version (video) of its promising wind turbine concept, we learn from MetaEfficient. A large kite is drawn upward to altitudes around 800 metres, where average wind speeds are four times as strong as they are near ground-based wind turbines. The kites power turbines by rising and flying back to gound level continuously. The retrieval phase is said to require a small fraction of the power that is generated during the flight. A first prototype was built in 2006. One of the recent improvements is an automatic launching system, powered by fans. The technology generated an interesting discussion at the Oil Drum last summer. Previously: Floating windmills – energy from the clouds. Related: Kiteboating & Kite Aerial Photography.

The Folly of Building-Integrated Wind

Building integrated wind

“The study found that predicted performance exceeded actual performance by a factor of 15 to 17. With the worst-performing systems, the electricity required to run the electronics exceeded the electricity production, so the wind turbines were net consumers of electricity”. Read.

Thanks, Brent Eubanks. Related: Small windmills put to the test / Urban Windmills harm the environment.