BBC News Online: UK

Cloud hangs over solar parking meters

The meters are not getting enough sunlight

The meters, the first in the country, came into operation earlier this year.

Previously they had only been used in sunnier places and now it has been revealed that the software inside them has been draining the batteries.

The company which makes the machines is working on a way to get around the problem.

"This is not happening and in a very few cases this has meant there has not been enough charge in the battery."

One way of improving the situation could be to cut back tree branches near some of the 215 meters to allow more light to reach the systems.

Mr Butt added: "This is the most ambitious scheme of its type in the country. There are bound to be teething problems."

Solar powered machines were chosen for the £1.1m scheme as they can be installed without the need for engineers to dig up roads and pavements to lay power cables.