Street lights: reducing CO2 and energy costs

The economic climate and Government schemes such as The Carbon Reduction Commitment Energy Efficiency Scheme (CRCEE) and The Climate Change Act, have meant that local councils are eager to reduce their carbon emissions and cut their energy costs.

According to The Institute of Lighting Professionals in the document Protecting a Vital Asset, 2000 there are approximately 6.2 million street lighting columns in public ownership in the UK.

The cost to run and maintain these light points takes a considerable chunk out of the country's expenditure and, with energy prices set to rise further, it is understandable that many local authorities are looking at ways of reducing the overall costs of street lighting.

In an attempt to realise savings, some local authorities have made the contentious decision to completely switch off their street lights.

In most instances, councils that are switching off are experiencing a serious backlash from unhappy residents.

Northamptonshire County Council switched off thousands of street lights to save GBP2m but, due to resident feedback, street lights on some routes have now been turned back on.

Residents have also appealed for street lights to be switched back on in other areas.

In Borehamwood, 1,300 people have joined a Facebook group called Turn Our Street Lights Back On in protest of street lights being switched off during the night.

The growing number of councils choosing to switch off their street lights is also receiving a backlash from MPs and safety groups, who fear that public safety is being compromised.

Fortunately, advances in lamp, ballast and wireless street lighting technology mean that a wartime blackout of street lighting doesn't have to be an option.

There are new wireless street lighting technologies, like Harvard's LeafNut solution, which recently won the Queen's Award in the Innovation category, that allow councils to programme and control street lighting systems, selectively dimming street lighting at different levels of intensity, either in clusters or individually.

This new breed of wireless control and monitoring systems allow local authorities to fully identify their lighting demands through an accurate inventory.

If councils know their street lights, they can manage them effectively.

Control gear is installed in each individual lamp, which then links to a central server, meaning that the lights can be managed wirelessly, over the internet, through a computer, laptop, tablet or mobile phone.

The system allows users to dim lights to a level which cannot be visibly noticed by the naked eye, while giving local authorities the convenience of turning lights back to full brightness in an emergency or for special occasions.

Due to the information passed between the street light and the central server, control and monitoring systems also allow operators to spot lamp problems in advance and predict lamp failure.

Due to this, street lighting managers can reduce their maintenance costs by setting up efficient maintenance schedules.

It has been proven that by installing such solutions, energy costs can be reduced by up to 40% and carbon emissions can be minimised by up to 50%.

Chris Hardy, president of the Institution of Lighting Professionals, said: "We generally think it is better to dim than switch off lights completely.

There are views that turning street lights off can lead to an increase in accidents.

According to one estimate, every pound spent on lighting saves four in reducing crime and accidents.

Harvard's LeafNut system has been deployed in approximately 100 locations across the world.

LeafNut can save up to GBP46 and up to 100kg of carbon emissions per street light, per year.