Home Energy Audits

I get asked frequently about how to lower power usage, reduce heating costs, etc. The following is not an authoritative treatment, its just a quick and easy way I've done it.

(1) Buy a Kill-A-Watt (see at right) and measure the power usage of every item in your household. They cost less than $30, and measure the instantaneous and average power usage of any appliance plugged into it. This helps you to establish which appliances are using the most electricity. Some sample data taken from my home in 2001 is shown at right. I used the resulting data to redo my home and cut my electrical usage significantly. Return on investment is less than one month.

The Kill-A-Watt also measures voltage, frequency, etc. and can be used as a diagnostic tool. Give it to your kids (with training), and they'll do the audit for you, as well as learn to turn the lights off when they leave the room.

SDG&E has an online audit tool that was completely misleading. It identified my #1 electrical annual cost item (pool pump) as #18.


Item Cost/Hour
pool pump
36" whole house fan
100w bulb
ceiling fan


(2) Buy an infrared thermometer (see at right) which measures the surface temperature of objects quite accurately. Use it to find hot and cold spots in a room, air leaks, what areas of your home need more insulation or sealing around leaky windows and doors. Cost ranges from about $25-50 and up, but the low cost ones work fine for home applications. Return on investment is less than three months.

(3) Convert most, if not all, of your incandescent bulbs to compact fluorescent's or, if you have the money, to LED lighting. You can now buy dimmable compact fluorescent's and the color temperature of these lights are gradually improving. SDG&E routinely has heavily discounted (or free) CFL's making the return on investment less than one month.


(4) The newer electrical appliances (refrigerators, washers/dryers, etc.) are much more efficient than earlier models and are well worth the extra cost, with payback periods of less than 2 years. Whole house heating units come in standard (typically 80-87%) and high efficiency types (typically 95%+) and cost several hundred dollars more but have payback periods, in some cases, of months, not years.