- Ken Wishaw
Turtle Shields - Creating Dark Sky Friendly Homes
Updated: Feb 1, 2021
As a member of the International Dark Sky Association and founding Board member of the Australasian Dark Sky Alliance, I am acutely aware that when you point a finger at someone else there are three fingers pointing backwards.
With that in mind I tackled my own home to make it a dark sky sensitive building. Living only 3km from a turtle nesting beach was an extra incentive to make this happen.
The problem was, I live in a high-rise unit of 71 apartments, in Maroochydore Queensland.
Yet I saw the opportunity not just to decrease our light footprint but also to decrease our carbon footprint and improve our bank balance. The final result was amazing!
After completing the audit, we had identified 99 light fixtures to change, on the outside of the building and a further 75 in the basement carpark.
The difficulty was in finding dark sky compliant lights. Perhaps only two percent of domestic outdoor lights could be considered dark sky sensitive and it took 18 months to find them.
Domestic lights vary enormously in quality and models have a high turnover. So, the lights I have used are not an official endorsement by ADSA, and may not even exist when you certify your building, but it serves as a general idea of what can be done.
Reception area and adjacent car park
We replaced 14, 300 watt halogen up lights with 30 watt 3000K (warm white) down-lights, 10 of these are on motion sensors.
We had mostly up/down lights. So, we just removed the up-light and kept the same fitting, now with 2700K globes (Philips MASTER LED Expert Color 5.5-50W GU10 927 24D. Also come in 5.3 mm pin fitting).
The pool decking had garish coloured up-lights. These were replaced with “Sunset” solar wall lights.
The open breezeways on each floor had wall mounted oyster lights, probably the worst idea for a wall light possible! These were replaced with 6 watt downlights (Havit HV3643T-WHT-240V) switched to 3000K.
We have one sensor wall light to replace (which is not open to sky but does not fit in with our philosophy), and we will use a Rye 1 sensor light with the bulb mentioned above. Finally the 75 basement fluorescent batons were replaced with intelligent motion sensitive LED batons.
We now have better quality lighting than before and have had no complaints, only compliments, from the residents.
The entire project cost $18,000. But we decreased our light signature dramatically and our carbon footprint by over 10 tonnes a month.
Our electricity bill has gone down an astounding $1,130 per month. So, the project will pay for itself in under eighteen months and by ten years we will be $117,000 ahead! Much of
that is basement lighting efficiencies but even the other lights are contributing to the savings.
Part of the savings will go into replacing the ceiling mounted oyster lights on ocean-side balconies with dimmed LED lights (Havit HV5805T-WHT) switched to 3000K. Although overpowered at 18W, these have an outside diameter of 157mm so a standard downpipe joiner fitted well, and with a bit of saw work was made into a shield preventing any light spill past the balcony.
Worth the effort? You bet!