The company claims the sodium silicide is a safe and stable powder, and when it generates hydrogen it does so at a pressure less than that inside a soda can. Pump a cartridge of the stuff full of water – it doesn't have to be drinking water, you can reportedly even use urine in a pinch – and the powder generates hydrogen to fuel the power assist on your bike, leaving behind only eco-safe sodium silicate and water vapor. The spent cartridge can be swapped for a fresh one; no need to wait around for a recharge.