A solar light tube provides natural daylight…

… and can cut your electricity costs

If you have a room that doesn’t get enough direct sunlight through windows, a solar light tube may help you get more natural daylight into the room. The lighting becomes more pleasant than that provided by electric lighting, and you can save on electricity costs.

A solar tube light comes in three parts. First, a roof-mounted unit receives both direct and indirect sunlight. Second, one or more lengths of metal tubing with a highly reflective interior surface channel the light downward. Third, a ceiling- or wall-mounted unit unit directs the light into a room. The in-room unit has a frosted surface so that the light is well blended.

If you have average skills at doing your own home improvements, you can easily install a solar light tube yourself into an existing, finished room. You’ll need to temporarily remove some shingles from your roof, and cut a hole through your roof boards. You’ll also need to temporarily move aside attic ceiling insulation, and cut a hole in the room ceiling. You install the end units in the roof and the ceiling, properly seal and reshingle the roof, install the tubing between the two units, and reinstall the insulation. A couple of hours of work and your solar tube light yields natural daylight even in cloudy weather or near dawn or dusk.

I haven’t installed one of these in my own home (my roof is covered in solar panels so there’s no way I could get light into the tube), but several of my friends have had great luck with them. One friend owns a top-storey apartment, with another apartment immediately to its south, so the living areas don’t get much direct sunlight. When they decided to add an upper floor for two extra bedrooms, they ran solar light tubes through the upstairs walls from the roof to the lower floor, and their living room and dining room are now bright enough that they don’t need any electric lighting during daylight hours.

Popular brands of solar tube lights include ODL, Natural Light, and Solatube among others.

Planning an installation

If you’re building a home from scratch, or you’re already gutting a room to renovate it, it takes very little extra effort and cost to put in a solar tube light, provided there is space to channel the light through its tube (through the attic, or through a thick interior wall or within a closet to reach a lower-floor room). You can buy several brands of solar tube light at most building centers, or right here online.

Typical units come with a 48″ section of metal tubing along with the roof and ceiling hardware. You may need to purchase additional lengths of tubing depending on the distance between the rooftop and the room opening. The roof opening and ceiling opening need not be in a direct line; because of the highly reflective interior surface, a solar tube light can accommodate several bends in the tube joints.

Installation does not typically require additional interior patching once the hole has been cut and the room unit installed. Of course it’s important to do a good job sealing the roof unit, reinstalling shingles around it, and covering any seams with a good roof sealant when you’re done.

For high-wind or hurricane-prone areas, get a severe weather unit certified for such extremes. These units have a rooftop unit with a stronger dome covering designed to withstand very high wind speeds.

Benefits of a solar light tube

People who have a solar light tube in their home find the light has a very pleasing, natural feel to it, and of course, once you’ve installed it, the light comes for free.

The rooftop portion of a solar light tube is very good at capturing even diffuse, low-level sunlight, so you can have natural daylight all day, from dawn to dusk.

Solar light tubes generally have an infrared barrier which allows visible-spectrum light into your home, but not solar heat (infrared radiation). This prevents the solar tube from heating your rooms in hot summer weather.

Solar skylight tubes are easier and cheaper to install than solar skylights in most situations. I would not dare attempt to install a solar skylight myself but I have plans to put solar skylight tubes in all four upstairs rooms of my own home in the near future.

Tax credits for solar light tubes

When you install a solar light tube you may be eligible for local, state/province, or federal tax credits or other incentives.

In the US, when you install a qualifying solar light tube you can get a 30% Federal tax credit, to a maximum of $1,500, which you can use to reduce your US Income tax payable.

In Canada, your installation can qualify for the home renovation tax credit, but then any renovation you do to your home will qualify. Just remember to hire a professional home energy auditor before you undertake any major renovation, both because they will help you focus on the most cost effective actions, and beause for many government / utility interest-free loans, grants or credits, an energy audit is required to qualify.

Consult your state/provincial, city, and utility websites for information on more locally targeted rebates and tax credits.