A Really Boring Way to Save $50/month or More!

LED bulbs for the win

Welcome to Saving Money with Andrew!

Recently, we moved to a rental house in the suburbs. It’s about twice the size of our old apartment and has central air, so I expected our electric bill to increase.

Four weeks later, the first bill came. It was 600% higher than our old apartment’s electric bill at the same time last year. Right then and there, I vowed to find the culprit and make sure this would never happen again.

We started with our four-year old, who habitually turns on the heat in the basement in the middle of one of the hottest summers on record (probably because he doesn’t believe in wearing clothes). Though annoying, the additional electricity couldn’t account for such a large increase.

Next, everyone always blames the air conditioning, so I had my suspicions. But even running 24/7 our AC would only use about half of the electricity on our bill. It had to be something else.

Finally, I realized…our house has a lot of lights, and despite all the warnings from my mother-in-law, we keep them on more than we should, especially now that we’re home all the time. By contrast, our previous home had a smart (and efficient) lighting system that was easy to turn off all at once.

Worst of all, every one of the 56 light bulbs in the house is an old incandescent, on average using about 75 watts each. Assuming 12 hours per day of usage times 75 watts times 30 days times 56 bulbs equals 1,512 kilowatt hours (kWh) per month, or more than one-third of our massive electric bill. At $0.11 per kWh, lighting represents an insane $166/month of electric usage.

Enter LED bulbs. Many households already use LED bulbs, but the majority still don’t, or use somewhat less efficient CFL bulbs.[1] Today, high-quality LED bulbs are cheap and basically indistinguishable from most incandescents. Most of our incandescent bulbs have a “color temperature” of soft white (2700K, the most common), so we made sure to choose soft white LED bulbs.

Some math on the bulb replacement:

  • A single new 60 watt-equivalent A19 LED bulb (the most common) costs less than $2 when purchased in a multipack from a major retailer. We checked reviews on Wirecutter for common A19 bulbs, and for other sizes just bought whatever had the best reviews.

  • That LED bulb consumes about 8.5 watts, or 51.5 fewer watts than an equivalent incandescent bulb, or approximately 0.6 fewer kWh per day at 12 hours per day of usage. Or approximately 18 fewer kWh per month for each bulb replaced.

  • At $0.11 per kWh, the monthly savings equates to about $1.98. Meaning that the new LED bulb has paid for itself in about a month. It’s not even worth waiting for the existing incandescent bulb to burn out, and this ignores the savings from not having to replace bulbs nearly as often (LED bulbs have estimated lifespans of about 25-50x that of an incandescent, though occasionally there are duds). So the math is extremely favorable, even for a rental house or one you’re going to stay in a short time.[2]

The case for LEDs is pretty overwhelming, with potential savings of as much as $145/month if we replace all of our bulbs, which we’re doing right now.

One last tip - many electric utilities are eager to get customers to use more efficient bulbs and appliances, and will even offer to conduct a free “energy audit” of your home to identify savings opportunities. Although many utilities have postponed these activities during COVID, some utilities are still offering heavily discounted pricing and rebates on LED lighting and efficient appliances. Check your local utility website.

If you haven’t yet, come join the LED club, do your part to reduce greenhouse emissions, and save a lot on your electric bill too![3] I’ll be back with a followup post in a couple of months to let you know how things are going and how much we saved.

I hope this has been helpful. If you liked it, please share it with a friend! Also, please send me your feedback, requests, and success stories.

Finally, Andrew’s pick of the week:

Drive & Listen is a really fun aggregator of first-person perspective videos of driving through cities all over the world, with street noise and local radio feeds to really give you that real-world driving experience. As someone who often enjoyed joyriding in the Grand Theft Auto series (rather than actually completing the game’s missions), it was really fun and strangely mesmerizing to take trips through a bunch of far-flung cities. Enjoy![4]

[1] Only 38% of residential “general purpose” lighting is LED, and only 16% of residential “decorative” lighting (such as chandelier bulbs, etc). If you’re really into this stuff, this DOE report discusses US light bulb usage in detail.

[2] Even the CFL to LED math is fairly compelling, though the payback period is longer.

[3] There are some pitfalls - make sure to check that your new LED bulbs can be used in recessed or enclosed fixtures (some can’t) and that if you are using dimmers, that they’re compatible with them (ours seem to work fine). When in doubt, check with an electrician.

[4] Hat tip to Vicki Boykis’s great newsletter Normcore Tech.