Small towns in Germany are offering an interesting solution to saving money and energy when it comes to street lighting.

The 900 residents of Morgenrothe-Rautenkranz enjoy a street lights on-demand service that saves the town around 4000 euros a year, which works out at around £3500.

The townspeople can call via their mobile phones to get the lighting turned on - so it's only powered up when needed.

Likewise, the town of Doblitz offers a modified mobile telephone in the electrical box controlling the street lamps that the town's citizens can call to make the lights come on for 15 minutes.

Dorentrup offers a slightly more complicated system that requires its townsfolk to register, and to enter a 6-digit number to identify the exact area that they want lit.

In a town called Rahden, a similar system exists - but the caller must pay to get the lights turned on with 60 minutes of light costing 3.50 euros.