In the 1930s and 1940s, decades after steam engines had made wind power obsolete, Dutch researchers obstinately kept improving the – already very sophisticated – traditional windmill.
The results were spectacular, and there is no doubt that today an army of ecogeeks could improve them even further. Would it make sense to revive the industrial windmill and again convert kinetic energy directly into mechanical energy?
A real-world test performed by the Dutch province of Zeeland (a very windy place) confirms our earlier analysis that small windmills are a fundamentally flawed technology (test results here, pdf in Dutch). Twelve of these much hyped machines were placed in a row on an open plain (picture above). Their energy yield was measured over a period of one year (April 1, 2008 - March 31, 2009), the average wind velocity during these 12 months was 3.8 meters per second (note: update on the wind speed). Three windmills broke. Find the disappointing results of the others below.
On an early afternoon last month, the Eugen Maersk (the world's longest ocean freighter at 1,300 feet) has left
Rotterdam, the Netherlands, on the tail end of a journey from Shanghai.
But the giant freighter is cruising at 10 knots, well shy of her
26-knot top speed. At about half speed, fuel consumption drops to 100-150 tons of fuel
a day from 350 tons, saving as much as $5,000 an hour.
The German Preussen (picture above), the largest sailing ship ever built, was launched in
1902 and travelled mainly between Hamburg
(Germany) and Iquique (Chile). It was rammed by a large steam vessel
1910. A one way trip between Germany and Chile took the cargo vessel between 58 and 79
days. The best average speed over a one way trip was 13.7 knots. The lowest average speed was 10 knots.
A small windmill on your roof or in the garden is an attractive idea. Unfortunately, micro wind turbines deliver hardly enough energy to power a light bulb. Their financial payback time is much longer than their life expectancy and in urban areas they will not even deliver as much energy as was needed to produce them. Sad, but true.
At great heights the wind blows much more powerfully and steadily than it does at lower altitudes. Some companies are convinced that there lies an opportunity to generate cheap, durable energy.
The most important disadvantage of wind power is that there is not always (enough) wind. Wind turbines only spin one tenth of the time at their maximum output, which makes wind not a very reliable energy source. At higher altitudes, wind conditions are much better. Floating windmills, which send the generated electricity to the earth by means of a cable, could harvest much more energy.
Considering the wind as an extra source of power, the fuel use of cargo ships can be reduced substantially.
Steam power and diesel engines relegated cargo sailing ships to the history books, since motorized ships are a lot faster, cheaper and more reliable. But now that the fuel use of ships and the ecological damage involved passes all bounds, there is a renewed interest in wind power as an extra source of energy; thanks to an extreme water sport.