Ronald Parise of Connecticut, USA, thinks he can make electric buses go farther. Today's batteries cannot store enough charge for those long journeys, and drivers usually do not like stopping for top-ups. Parise proposes using a radio antenna on top of the bus to pick up microwave signals from overhead transmitters placed every few hundred metres along the streets. Microwave energy is converted into electricity, which charges the battery or keeps an onboard flywheel spinning. For safety reasons, the transmitters only switch on when a bus is directly underneath. Each bus has its own low-power radio beacon, which triggers the transmitter when it gets within range.