23 November 2001

On the move with wind power

A PROTOTYPE mobile wind powered generator which can produce up to 20kW of power made an appearance at Agritechnica.

The invention of Dr Irps of the FAL-BB based at Braunschweig, Germany, the MoWec comprises two three-bladed propellers with diameters of 7.1m which results in a total swept area of 80sq m.

"The important factor we considered when designing the unit was to ensure it was not greater than 10m high," explains Dr Irps. "Over this height and planning permission would have been necessary."

Unlike other larger wind powered generators, the blades on the propellers do not feather to restrict their speed of rotation should wind speeds become excessive. At wind speeds in excess of 11m/sec (22.5mph) the unit pivots the propellers to an angle so they are not directly facing the wind.

Drive from the propellers is currently by chain down to a single shaft which then, through a series of geared directional changes emerges as a shaft drive at the units drawbar where a generator can be installed and driven. Dr Irps says he intends to fit future models with drive shafts through out and possibly mount the generator on the centre of the machine which would avoid the frictional losses being incurred at present.

Dr Irps also believes the power from the MoWec unit could also be used to pump water, air compressor or a multitude of tasks where a rotational force is required.

"The important point to note is that the unit is totally mobile and can be towed to any point where power is necessary," says Dr Irps.

When in transport the machine folds down hydraulically to create a compact unit just 2.8m wide. Price of production units isexpected to be in the region of DM80,000 (£26,403). &#42