A Little Light On LED Streetlights

Exciting news: After two years of discussions with the Kapiti Coast District Council (KCDC), Kakariki St has a street lighting trial of five smart LED lights. Four are at the North end of Tilley Road and one at the bottom end of Te Miti St where it meets Tilley.

Back when we began the Kakariki Street project there were a lot of ideas about what we could do to make our corner greener.

I had heard of ‘intelligent’ street lighting and thought to investigate this further. I called one of the companies that I knew were designing them and lo they had an information afternoon on that very week to promote them to all the lower North Island councils, so I got myself invited to the event.

It was a really informative afternoon and some people from KCDC including Jake Roos, Senior Advisor Climate Change and Energy, were there to learn too. I began talking to them about what it would take to get some installed on our street. Not surprisingly, it came down to the numbers working and getting both council decision makers and residents onside.

So began two years of discussions with KCDC about LEDs for our street (mostly me phoning Jake regularly to request them). Then one day he got a call from a small local lighting company called KTL saying they were looking for somewhere to trial some new LED lights they had developed, and Jake said that he knew of just the perfect place!

The Electra guys installing our new Silverlight500 streetlights

The Electra guys installing our new Silverlight500 streetlights

Everything lined up, and KTL were able to install their first ever street trial of the Silverlight500 in our neighbourhood. This new design has one really compelling point of difference to any other LED street lights I have seen. KTL have designed a panel that can slot into the existing housing of the current standard sodium lightbulbs. According to the guys from Electra who were contracted to put them in, the Silverlight500 is incredibly easy to retrofit. This in turn means it is not only relatively cheap to install, but also less wasteful due to using the existing fittings.

Back at the council, Jake got busy doing some detailed number crunching, and in the end the case is really compelling. Essentially, the lights will pay for themselves fairly quickly in power savings and then continue to save both power and money in the long term -who can argue with that!

Here are some of the reasons we are trialling them: The lights consume just 50% of the power of sodium bulbs when on full, but are twice as bright. They can be dimmed to 75%, 50% and 25%. They have a much reduced ‘light spill’ only lighting the street but not the surrounding houses. This reduction in light pollution is great news for our night sky and wildlife. Each light can be controlled individually via the internet, and any issues such as blown bulbs can be detected remotely, thus reducing maintenance costs and delays. They are white like moonlight which really improves visibility. They are a retro-fit design, so not wasteful or expensive to install. The new LEDs are supposed to last 30 years instead of 5 for the sodium bulbs.

A happy crew from KTL, KCDC and a couple of local residents celebrate the Silverlight 500 trial install

A happy crew from KTL, KCDC and local residents celebrate the Silverlight 500 install

In an informal discussion about the trial, someone asked if the light fittings could be moved down the lampposts a bit lower so as to shed light on the street but not ruin the sight of stars on the beach (we have a road that runs parallel to the beach here in Paekakariki). The answer is a No but Yes! Confused? Well, the lights have a special lens (designed in Finland) over the LED. This focuses the light, throwing it only along the road corridor and dramatically reducing light spill into the surrounding properties and night sky. There is no need to lower the light fittings on the lampposts as the special lens takes care of this problem already. The front of our property for example, is much darker now with the Silverlight500 than it was with the sodiums, and that is true even when these new lights are on at 100% power and producing twice the light of the old sodiums. I think we could happily set the light levels to 50% or even 25% which is way dimmer than what the sodiums produce thereby saving more power. We could potentially use just 10-20% of the power required by the sodiums. This is for two reasons; firstly because LEDs use less power to produce the same lumens (light levels), and secondly because you need less of the clear white light for visibility than with the orange sodium bulbs. I’ve been surprised by how much my expectations have been exceeded on this one.

One of the earlier lenses tested in this trial which was later replaced by one that gave a more even light distribution

One of the earlier lenses tested in this trial which was later replaced by one that gave a more even light distribution

The trial finished with a survey of households in the area. We were told that if the trial was technically successful and residents responded well, we’d get to keep them and the council would seriously look at a Paekakariki and Kapiti wide roll out.

Over the course of several weeks after the initial install, the very nice KTL guys took onboard the resident’s feedback, looked at their own data, and tried out a couple of different lenses to get just the right light throw. There was some initial trouble trying to get the light evened out so that the street didn’t have too extreme a contrast between light and dark patches. Happily, the end result is very close to perfect now, and we are pleased whenever we arrive home at night to see our little end of the road with it’s lovely clear silvery street lighting. Here’s hoping the rest of Paekakariki village and Kapiti will soon be able to enjoy this too.

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One Response to A Little Light On LED Streetlights

  1. Dave Launder says:

    Brenda and especially Flo
    This was a great chance to identify with and share values with others.
    The resulting lighting was only part of it, the whole ethos fits our low impact approach and the principle of minimising energy use yet recognising the amenity as being a necessary part of life is how all of nz should think.
    You have a gem as Paekakariki and we will be back
    Agree about Jake … He’s pretty special in this world

    Very best wishes and ongoing encouragement from KTL

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