Honolulu Mayor Kirk Caldwell and his administration are ready to make a significant change to Honolulu’s neighborhoods and Hawaii’s night sky by replacing all of the city’s streetlights with light-emitting diodes or LEDs. This has been hailed as a great energy saver and safety improvement, but have concerns about LED lighting been adequately considered and mitigated? Are we using this relatively new technology the best we can, without producing negative consequences we may regret for years to come?

The city’s plan includes using 4000K lights. Part of the sales pitch we’ve been given is that this is the equivalent of moonlight. That sounds OK, but we must remember that these streetlights will be 50 to 100 times brighter than the moon.

When we look at a color spectrum of 4000K LED compared to moonlight, we see that there is much more blue in the LED. If part of the goal is to have lighting that is similar to moonlight, we’d be better off going with 2200K LEDs. The energy tradeoff is not significant.

In the top image, color spectrum analyses for moonlight and 4000K LED lighting look quite different. In the bottom image, similar analyses of moonlight and 2200K LED light bear striking similarities.

Why does color matter? Blue produces more glare, even in fully shielded housings. (This may be why the pilot LEDs on Lowrey Avenue have drawn such strong criticism — they look like they are not shielded.) Glare can be irritating and distracting, and for some people, even painful. The light from LEDs also reflects off streets and sidewalks, reducing visibility of stars at night.

Another concern about the blue in LEDs is the potential impact on our health. There is a large body of evidence that indicates blue lights reduce production of melatonin in the body. Without it, sleep patterns are disrupted, and cancer risks are increased. Studies also point to other health concerns and negative impacts on wildlife. Other cities have revised their lighting plans after learning about these and other concerns.

Why is the city not installing dimmable LEDs? Initial costs may be higher, but in the long run, they save energy and extend the life of the fixture components. We need to take a closer look at this possibility.


Two fully shielded lights — LED in the foreground and high-pressure sodium in the background.

Bob King

LEDs require air flow for long life, yet the request for proposals indicates that glass lenses will be used. Should different specifications be considered?

Why have we not been told the cost of the project? Surely the city has some available projections. Otherwise how can we tell whether this decision makes sense? We know $80,000 was budgeted for preparation of the RFP, and almost $2 million has been taken from HECO ratepayers’ pockets to be put into the city’s coffers as the LEDs are installed. But what will we have to trade for the annual savings of $3 million?

Is the warranty period long enough?

The RFP requires our old streetlights to be recycled, as required by current laws, rules and guidelines. Since we have no recycling facilities, and other municipalities are switching out their high pressure sodium lamps, will we end up with a bunch of fixtures in our landfill?

After looking at the request for proposals and doing some research, I found more questions than answers. What this boils down to from my perspective is the need for much more information from the city, as well as discussions with the public.

The City Council’s budget committee will discuss and vote on Resolution 15-215 Wednesday. The resolution asks the city to report to the council about the LED project. This is certainly a step in the right direction. We should also be looking at creating a lighting ordinance that takes into consideration the concerns mentioned here, as well as protection of our night sky.

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