Losing your power due to a natural disaster or weather event can be traumatic, but even the simplest power outage, such as when a power line gets cut or goes down, can create a headache for unprepared homeowners. Those people living in areas where these things happen regularly are more likely to be ready, but for the rest of us there’s a simple way to at least get some light on the situation without having to hunt around for batteries or matches.

The Blackout Buddy H2O flashlight features a magnesium-oxide battery module which when topped up with ordinary tap water delivers enough electrical power to light up the unit for hours at a time. The blurb says that if you top up the flashlight with water once a day, you’ll have a working lamp for up to 72 hours.

The torch is a fairly small affair, so don’t expect floodlight levels of illumination, but for emergency use, this has to be a pretty solid option. Sure it’s more expensive than just buying an ordinary flashlight with conventional batteries, but can you guarantee that the flashlight you have in the basement for emergencies has working batteries inside it after all those years? The product costs $15.16 and can be stored for up to 10 years without degradation.