Whanganui District Council has already saved more than $100,000 in electricity costs during the roll-out of its LED streetlight replacement project, with final cost savings of $6 million expected.

About 2500 residential streetlights have been replaced with the LED (light-emitting diode) lights since the project began in the 2015 to 2016 financial year.

By the project's end, 5500 lights will have been upgraded with the help of 85 per cent funding from the New Zealand Transport Agency.

Street-lighting energy costs have reduced from $457,842 in 2015 to 2016 to $350,649 in 2016 to 2017, says council senior roading engineer Rui Leitao.


"This is a significant saving for the council and one of the benefits of LEDs, as the lights have a much lower wattage than the previous lights, making them cheaper to run," he says.

As well as being more energy efficient then the older technology high-pressure sodium (HPS/SON) streetlights, they have a much longer replacement timeframe and provide improved lighting for motorists and pedestrians.

"As the technology is fairly new, we have made sure we've purchased LED products that are of high-quality and performance.

"LED lamps need to be replaced every 20 years, compared to about eight years for HPS and other lights."

LED street lights are easy to spot once you know what to look for, Mr Leitao says, as they emit a white light, rather than the yellow light of the older fixtures.

The white light only projects downwards, creating a different visual effect from the former lights.

"The lights show true colours and the light spreads differently.

"Pedestrians are also easier to see."

The council will invest about $3m during the roll-out with expected savings in electricity and maintenance costs of $9m, resulting in direct savings of $6m over the LED lights' lifetime.

The project was initially expected to take five years, but with the NZTA upping its funding from 62 per cent to 85 per cent, it will now be completed by the end of next June.

"It's a win-win situation," says Mr Leitao.

The project began firstly as a trial on the Whanganui City Bridge, extended to main arterial routes and is now spreading throughout the suburbs.

The roll-out of these improvements is part of a council maintenance and improvements contract with Strong Electrical.

Most of the LED replacement in Castlecliff and Springvale is complete and the Strong Electrical LED team is currently working in Aramoho, says Mr Leitao.