While it’s good news that UPS is switching to an all-electric fleet in London, a switch like that can still provide major headaches for utility companies. Fortunately, UPS is using on-site batteries and smart-grid software to time the recharging of its 170 electric trucks so that it occurs when energy demand is low. That may not sound like a big deal, but the new software is the first of its kind and signals the latest milestone in the mass integration of plug-in electric vehicles.