It's not likely to win any prizes for Britain's sunniest beach.

But solar power is being harnessed at public toilets on Portobello's promenade, perhaps lighting the way forward across the city.

The loos and washrooms have been fitted with a giant rooftop solar panel which catches what sunshine there is and uses it to heat water for the sinks.

The toilets have been fitted with a solar window containing black plastic pipes through which cold water is pumped and heated by the sun. The water is then pumped into the tank, providing hot water for the taps almost all year round.

Even the pumping system is designed to make best use of the environment - a small solar panel sits on the roof providing electricity for the motor.