Almost half a million public lights across the country - some of them 40 years old - are to be upgraded with energy saving light bulbs as the Government bids to cut their annual cost of €56m.

Minister for Communications, Climate Action and Environment Denis Naughten briefed his ministerial colleagues on the plan at today's Cabinet meeting.

In 2009, the Government set a national target for Ireland to improve energy efficiency by 20% by 2020.

A higher target of 33% was set for the public sector to demonstrate leadership in the area of energy efficiency.

There are 480,000 public lamps across the country and they account for €56m in energy expenditure every year.

As this amounts to half of the energy consumption of the 31 local authorities, Minister Naughten told Cabinet that it is crucial they are updated to energy efficient bulbs.

As parts of the public lighting network are over 40 years old, it is estimated that replacing bulbs with low energy equipment would see local authorities halve their €56m annual lighting costs.

The Government has set aside €9m this year to contribute to the upgrade of the national public lighting network.

Minister Naughten updated the Government on the progress of the Public Sector Energy Efficiency Strategy today.

€750m has been allocated to a retrofit programme for the public sector where the focus is on areas such as public lighting, schools, hospitals and government buildings.

Energy upgrades have taken place in ten schools to date, resulting in energy savings of 40-60%.

School closures, which would have arisen due to broken heating systems with old radiators, have been avoided.

Acute hospitals are among the biggest energy users in the public sector.

Cabinet was also briefed today on a Health Service Executive initiative for a major energy efficiency upgrade of the Mater Hospital in Dublin.