Last weekend six solar tube skylights were installed in our office, which occupies the top floor of a two storey building. The skylights have eliminated the need for artificial lighting in thirteen of our work spaces.
It was amazing watching the reaction of staff as they came in this morning, many couldn’t contain their excitement. “Its so much brighter.” “The quality of light is fantastic.” “We don’t need the lights on at all.”
The cost installed was $5,550. Our landlord agreed to pay half of the costs. As we were pretty frugal with our lighting to start with, and it was already efficient, the lighting energy cost savings won’t be large, in the order of $500 a year. We may have to run the air conditioner more in summer because of the heat gain from the skylights, but this may also cut heating energy use in winter. Assuming it balances out the payback for us as tenants will probably be around 5 to 6 years in terms of energy savings. However daylight also makes the workplace more attractive, and may improve productivity. So there will be other benefits in addition to the cost savings. And of course the greenhouse gas savings will reduce the amount of green-power we need to purchase. If we were buying black power the skylights would be expected to save us around 2.5 tonnes of greenhouse gas a year.