This is why street lights across Portsmouth will be dimmed at night

Following a trial last year city councillors approved the complete roll-out of adaptive street lighting, which will see most LED lights dimmed by 50 per cent between 10pm and 6am.

Combined with the 2018 switch from traditional bulbs to more energy-efficient lights, it is thought the council has reduced its energy use by 40 per cent - saving around £420,000 a year.

Lights in certain areas, including the city centre, will remain at full brightness to allay concerns about crime.

At a cabinet meeting yesterday Councillor Lynne Stagg said: 'I went to a demonstration in Fawcett Road and Victoria Road North.

'Between where we were standing there was an alleyway. I said “that's a potential area for crime”.

'They said “it's not a problem because we can target individual ones and keep the lights there brighter and dim the other ones”.'

The six-week trial was in Baffins, Cosham, St Jude, Milton and Fratton and affected 12,000 residents. However, lights in one of these areas was not changed to act as a placebo.

In their feedback most residents said they noticed a difference in lighting levels, but a higher percentage noticed a difference in the placebo area where lighting levels were not adjusted. Out of the 12,000 residents invited to comment, the council received 83 responses from people living in the areas, and of those seven were not in favour - with two from the placebo patch.

Cllr Lee Hunt said: 'I remember there was a nervousness about whether we should ask residents in an open way.

'And it's really interesting how a higher percentage of people noticed more of a difference in the placebo area. That shows how it's about perception.'

Cllr Steve Pitt added: 'There have been genuine concerns about the increase in in brightness on wildlife. By doing this we reduce that impact.'

A total of 15,000 bulbs have been replaced by LED lights since 2018.

Heritage street lights in areas such as Old Portsmouth and parts of Southsea have not been changed.