You don’t need panels on the roof to put the sun to work. The sun is already hitting your house every day. The question is whether it’s helping you or running up your bill.
Blinds Are the Cheapest Solar Equipment You Own#
In summer, close the blinds and curtains on your southern windows to reflect the heat from the sun back outside. In winter, open ’em up to let the free heat in. Just keep in mind what the neighbors can see.
It sounds too simple to matter, but windows are one of the biggest sources of heat gain in a house. Sunlight comes through the glass, hits your floor and furniture, and turns into heat that’s stuck inside. The U.S. Department of Energy notes that medium-colored draperies with white plastic backings can reduce heat gain by about a third, and plenty of guides put the savings from good window coverings even higher. Closing the blinds before you leave for work on a hot day means the air conditioner has less to fight when you get home.
A few tips that help:
- South and west windows matter most in the summer. West windows get the hot late-afternoon sun.
- Light-colored or reflective backings on curtains bounce more heat back out.
- Exterior shade beats interior shade. Awnings, a pergola, or a deciduous tree on the south side block the heat before it even reaches the glass. Trees that drop their leaves in fall let the winter sun back in for free.
- In winter, reverse it. Open south-facing blinds on sunny days and close them at night to hold the heat in.
The Thermostat Request Isn’t a Joke#
When your power company recommends people set their thermostat to 78, they’re asking nicely. Warm indoors with electricity is better than hot indoors with no electricity.
During a heat wave, everyone’s air conditioner runs at the same time, usually late in the afternoon. That’s when the grid is most likely to hit its limits. Utilities and grid operators would much rather ask everyone to bump the thermostat up a few degrees than resort to rolling blackouts. If enough people listen, it works.
The Department of Energy also says you can save up to about 10% a year on heating and cooling by adjusting your thermostat 7 to 10 degrees from its normal setting for 8 hours a day, like while you’re at work. A smart or programmable thermostat makes that automatic. Pair it with a ceiling fan, which makes a room feel several degrees cooler, and 78 isn’t nearly as bad as it sounds.
Location, Location, Location#
The sun matters outside the house too. If you work the day shift, living due west of your workplace isn’t very bright. Actually, it will be very bright, as you stare into the rising sun on your way to work and the setting sun on your way home.
Sun glare is a real safety hazard, especially on east-west roads in the spring and fall when the sun sits low right at rush hour. If you’re house hunting or job hunting, it’s worth a look at the map. If you’re already stuck with a sunny commute, keep a pair of sunglasses in the car, keep your windshield clean inside and out (glare makes a dirty windshield nearly impossible to see through), and leave extra following distance.
Work With It, Not Against It#
None of this costs much, if anything. It’s just paying attention to where the sun is and when. People did this for generations before central air existed, and it still works. Let the sun heat your house when you want heat, block it when you don’t, and keep it out of your eyes on the drive home.
Sources: U.S. Department of Energy, Energy Efficient Window Coverings and Programmable Thermostats.
