Every made a recipe where the only instruction was ‘just add water’? Well, that’s the idea with this alarm clock. It’s powered by water, with a electrochemical reaction and you just top it up when supplies run low. Fortunately you won’t have to do that every bedtime as it should only need topping up every three months.

It’s green, it has recylable components and it’s quite a cool idea. It costs 319.99 at the Gadget Shop.

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