Rangers across Africa’s national parks and wildlife reserves are in a constant battle to protect endangered species from poachers. But those rangers are at a disadvantage: their loud gasoline-powered motorbikes alert poachers to their presence. Swedish electric-bike company CAKE worked with the Southern African Wildlife College to adapt their Kalk bike, giving it a super-quiet electric motor and a portable solar-panel charger. For $25,000, consumers can buy their own solar-powered bike—which will also pay for another to be sent to the anti-poaching fight. —Ciara Nugent