Silent Rooftop Wind Turbines Could Generate Half of a Household's Energy Needs

Small wind turbines scaled to the right size for residential and urban areas have so far lived in the shadows of their larger wind-farm-sized counterparts. The power output has been too low for a reasonable return on investment through energy savings and the noise they produce is louder than most homeowners can deal with.

A Dutch renewable energy start-up called The Archimedes is working to solve both of those problems in a new class of small-scale wind turbine -- one that is almost silent and is far more efficient at converting wind into energy. The company states that the Liam F1 turbine could generate 1,500 kWh of energy per year at wind speeds of 5m/s, enough to cover half of an average household's energy use.

When used in combination with rooftop solar panels, a house could run off grid. "When there is wind you use the energy produced by the wind turbine; when the sun is shining you use the solar cells to produce the energy," The Archimedes CEO Richard Ruijtenbeek said.

The Liam's blades are shaped like a Nautilus shell. The design allows it to point into the wind to capture the most amount of energy, while also producing very little sound. The inventor of the turbine Marinus Mieremet says that the power output is 80 percent of the theoretical maximum energy that could be harnessed from the wind.

“Generally speaking, there is a difference in pressure in front and behind of the rotor blades of a windmill. However, this is not the case with the Liam F1. The difference in pressure is created by the spatial figure in the spiral blade. This results in a much better performance. Even when the wind is blowing at an angle of 60 degrees into the rotor, it will start to spin. We do not require expensive software: because of its conical shape, the wind turbine yaws itself automatically into the optimal wind direction. Just like a wind vane. And because the wind turbine encounters minimal resistance, he is virtually silent," said Mieremet.

The company is also working on even smaller wind turbine designs that could fit on LED lampposts to power them, on boats or in smaller bodies of water.

You can watch a video about the history of the Liam turbine from invention to field tests below.