The two-seated power glider Arcus has been electrified by Willi Balz, a passionate pilot, but also an industrialist of aeolian energy (info@windreich.ag). 20 meters wingspan, a 40 hp engine on a retractable mast and in the wings lithium-polymer batteries. They are recharged with which energy, you ask me? With a wind turbine on the roof of the hangar that stores the energy in simple lead-acid batteries to make up for days without wind. Willy is a purist. I could fly the Arcus near Stuttgart for half an hour with no thermal lift and there were still 35% of reserves. In the right season, the batteries give more than enough to catch the upwash and go for a flight of hundreds of kilometers! Hard to believe that some people still buy traditional combustion engines.