For green bunnies everywhere looking to save the environment as well as a few pennies along the way, the water powered alarm clock should be just the ticket.

No electricity needed, no batteries required - just add water to power up your alarm clock and keep it topped up as the water evaporates for a constant supply of energy.

It works thanks to an electrochemical reaction between the electrodes and water, which produces enough electrical energy to power it, and in keeping with its green theme, all of the bits in the water powered alarm clock are recyclable.

You'll be able to tell the time, and set an alarm on it - but it will also work as a timer and tell the temperature too.

Once you've filled it, you should have at least 3 months power to go on before you need to top it up. Even better, you'll never be duped by dead batteries or a power cut again!

The water powered alarm clock is available now and costs £19.99.