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Lighting Seattle since 1905 Jorge Carrasco, Superintendent
Conservation: Q and A Conservation: Frequently Asked Questions


Energy Costs

Home Heating
  • Does it save energy if I turn down my thermostat when I am asleep or away from home?
  • Does it take more energy to heat up my cold house in the morning or keep the temperature constant all day and night?
  • Do they make more accurate or programmable thermostats for baseboard heaters?
  • Which fuel is the cheapest to use to heat my home?
  • What kind of electric heat is the most efficient?
  • Should I switch from electric heat to gas heat?
  • Won't my plants die if I turn my heat off at night?
Home Weatherization Lighting Water Heaters Questions Not Listed Above

What is the easiest thing I can do to lower my electric bill?

For an average Seattle family, the top two users of electricity are electric (home heating) and water heating. Reducing the electricity used in these 2 areas can make the biggest difference on your bill.

If you heat with electricity (with electric furnace, wall fans, baseboards or portable heaters), we recommend setting your thermostat to 68 degrees when you are home and 55 degrees when away or asleep. Setbacks of just one degree can save about 3% of your heating bill. For water heating, we recommend setting the tank to 120 or 130 degrees. Note: 120 degrees is the preferred setting for safety and economy but if you use an automatic dishwasher that does not have a hot water temperature booster, you will need to set your tank at 130 degrees in order to get proper cleaning.

For more detailed information, you may download our free booklet entitled "Do-It-Yourself Home Energy Audit: A Step-by-Step Guide for Identifying and Improving Your Home's Energy Efficiency". To order the booklet by email, please complete and submit the Community Conservation E-mail Request Form below.

Where can I get an electric water heater tank wrap?
You can buy a water heater blanket in most home centers and hardware stores. However, you may get little benefit from wrapping your water tank because tanks made after 1989 already have extra insulation inside them in order to meet strict federal energy efficiency standards. You will have better savings and a more pleasant task if, instead of wrapping your tank, you check the temperature of your hot water and set your water heater back to 120 or 130 degrees. Of course, when it's time to replace your water heater, be sure to buy an energy efficient model.

What is the recommended temperature setting for my water heater?
Both the top and bottom elements of your tank should be set at 120 degrees, unless you have a dishwasher that does not have a temperature booster. In that case, set both thermostats to 130 degrees. Check your water temperature with an accurate thermometer. Do not trust the numbers on the water heater itself. Setting your water temperature at 120 or 130 degrees not only saves energy, it prolongs the life of your tank and reduces the danger of scalding from water that is too hot.

What appliances in my home use the most electricity?
Electric furnaces and water heaters. Energy use is determined by the amount of power used (measured in watts or kilowatts) and the amount of time (hours) the appliance operates. Appliances that use lots of power are usually those that produce heat, such as electric furnaces, water heaters, stoves, ovens, irons, toasters and hair dryers. Appliances that operate for long periods of time include furnaces, water heaters, refrigerators, freezers and pool pumps and some light fixtures. Since electric furnaces and water heaters use a lot of power and operate long periods of time, these 2 appliances use the most electricity. For a more complete list of appliances and their average electric use, click here, or you may download our brochure entitled "Your Electric Appliances".

What does Seattle City Light charge for my electricity use?
Seattle City Light rates are structured to provide an initial block of inexpensive electricity to cover basic life needs such as cooking, hot water and refrigeration.
Rates in effect as of January, 2007:

Basic Service Charge: The basic rate is $0.0973 per meter per day.
  • For the first 10 kWh per day on average in summer or 16 kWh per day on average in winter, you pay the rate of $0.0376 per kWh.
  • For additional use over 11 kWh per day on average in summer or over 17 kWh on average in winter, you pay the rate of $0.0793 per kWh.
NOTE: The normal billing period ranges from 57-63 days. To figure the average kWh use per day, Seattle City Light takes the total number of kWh used and divides by the number of days in the billing period.

Click here to go to Seattle City Light's Rates Home Page.

What is a kilowatt-hour?
A kilowatt-hour (kWh) is one thousand watts used for one hour. Just think if you have ten 100-watt lightbulbs (ten x 100 = 1,000) burning for one hour, that is one kWh; and Seattle City Light would charge you about 7.93 cents for those 1,000 watts used during that hour.

How do I figure the cost of running my electric appliances?
You first need to know how much power the appliance draws. This is measured in kilowatts (kW). There are 1000 watts in a kilowatt. For example, a 100-watt lightbulb that is on for one hour uses one-tenth of a kW of power. Click here for a list of common household appliances and their average hourly and bi-monthly electrical costs at the most current rates.

For appliances other than lightbulbs, look for the number of watts or amps on a plate or tag usually located in the back or underside. If the plate shows amps, you must convert amps to watts. By definition, watts = amps x volts. In the U.S, standard house current is 120 volts, so an appliance that draws 6 amps also draws 720 watts (6 amps x 120 volts). If the plate shows horsepower, the general equation is 1 hp equals .746 kilowatts. Click here to use our calculator to find out the cost of your appliances.

Does it save energy to turn down my thermostat when I am asleep or when I am not at home?
You will save energy by turning down your thermostat at any time. Turning it down to 55 degrees or off when you sleep and when you are away from home makes the most sense because you will experience little discomfort as a result. If you really want economy with comfort, install a new electronic, automatic setback thermostat for your furnace. These thermostats are available in home centers and hardware stores. They allow you to reheat your house in anticipation of your return home.

Do plastic "storm window" treatments really work to reduce my energy costs?
Yes. In addition, caulking and weatherstripping all doors and windows will also help lower your costs. Also, installing outlet and switchplate gaskets will help. Doing these things will cost very little but can increase your wintertime comfort as well as save you money.

How do I know if I need to add insulation to my home?
If you have no insulation in your attic, walls and/or crawlspace, adding insulation makes sense. Seattle City Light recommends these amounts: Attics--about 12 to 14 inches (R38), Walls--about 4 inches (R11), Crawlspace--about 6 inches (R19). If you have some insulation in these areas, adding more will reduce the heat you lose, but the amount of heat you save will depend on how much insulation is already in place. Depending on how much is there already, adding more insulation may increase your comfort even if the increase isn't justified by cost savings.

If a contractor is doing the work, adding to pre-existing insulation in walls and crawl spaces may not increase your savings enough to justify the cost. If you are basing your decision strictly on cost savings, add insulation to an attic only if the total amount already in place is less than 3 inches thick. If you are doing the job yourself (and have to pay material costs), adding to insulation in the attic makes sense. Adding to insulation in crawl spaces and walls probably does not make sense because its too much work and not cost-effective. Professional installers use loosefill insulation whenever possible because it is so much easier to put in place than blankets, so you may want to investigate using this technique yourself.

What is the difference between compact fluorescent bulbs and incandescent (standard) light bulbs?

A compact fluorescent bulb lasts up to 10 times longer and uses 75% less energy than an incandescent bulb, while giving off the same amount and quality of light. It does this by using fluorescent technology in a completely new way: by folding up the tubes, improving the light quality, starting flicker-free and attaching the whole works onto a regular screw-base so that fluorescent bulbs can fit where your standard bulbs are now. Visit our Efficient Lighting website for information on energy efficient lighting, including "Compact Fluorescent Bulbs".

How can I save hot water costs?
Install energy efficient (low flow) aerators for kitchen and bathroom faucets and an energy efficient (low flow) showerhead. Take a short shower instead of a bath. For more tips, visit Seattle Public Utility's Saving Water Partnership web page.

Which fuel is the cheapest to use to heat my home?
If we compare oil, natural gas and electricity we see that natural gas is clearly the cheapest of the three at today's fuel prices. For a detailed look at heating costs for various fuels visit our fuel cost comparisons.

What kind of electric heat is the most efficient?
All electric heaters except heat pumps are 100% efficient in converting electricity to heat. Heat pumps have an efficiency of 200% or more. However, different kinds of electric heaters are less effective in making the heat they product go to where it's wanted. Baseboard heaters are arguable the worst at distributing their heat, and floor type radiant systems are probably the best. For more information you may download our brochure entitled "Purchasing a Heat Pump".

Should I switch from electric heat to gas heat?
Whether or not it makes economic sense to replace an electric furnace with a gas furnace depends on a lot of factors:
  • How much energy do you use each year to heat your home?
  • How much will it cost you to hook your house up to a gas main?
  • How much will it cost to install a gas furnace?
You can figure approximately how much electricity you use to heat your home if you have your City Light bills for the last year.

The gas company should be able to tell you how much it will cost to hook your house up to the gas main. If there is no gas main in the street in front of your house, you probably won't be able to cost-justify switching furnaces.

Heating contractors will give you a free estimate of the cost of installing a new gas furnace in your home.

If you're currently using 12,000 kWh per year to heat your home, it will take you about eight years to pay back a $5000 gas furnace installation at today's prices for electricity and natural gas.

Does it take more energy to heat up my cold house in the morning, or keep the temperature constant all day and night?
With today's modern heating equipment and building practices, a home in Seattle will rarely get colder than 55&#deg; overnight, even in the dead of winter. Using a correctly sized heater, a room takes only about 20 minutes to heat from 55&#deg; to 68&#deg;. Compare this to having the heat on all night, and the savings are substantial. If there is a room you want warm when you wake up or arrive back home, consider installing an automatic setback thermostat in that room.

Won't my plants die if I turn my heat off at night?
Most common houseplants do not suffer unless the temperature remains lower than 45&#deg; for several weeks. If your home feels really cold at night, check for cold air leaks and seal them with weatherstripping or caulk.

Do they make more accurate or programmable thermostats for baseboard heaters?
Yes. You can now find programmable AND more accurate thermostats made especially for baseboard heaters as most home improvement or hardware stores. But before you go, find out if your baseboard thermostats are single-pole (two-wires coming in from the wall) or double-pole (four wires coming in from the wall). Most are single-pole and not always interchangeable. (A double-pole thermostat will have an "Off" setting.)

Questions Not Listed Above
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