Is it worth changing the Lightbulb?

Switching for a more efficient lightbulb for economic reasons

Martin Thoma
Plain and Simple
Published in
5 min readSep 18, 2021

--

A rough estimation how much energy the four different types of lamps use to get a specific brightness. The old incandescent lamps are clearly the worst. Interestingly, LEDs get manufactured also for very low brightness lamps. This image was created by Martin Thoma. The light bulb images were created by Emoji One; Simon Eugster; Artoria2e5; Smalllikeart (Old, Halogen, CFL, LED)

Electricity is pretty expensive in Germany. We pay around 0.30 EUR/kWh. A normal two person household uses around 2500 kWh/year which makes 750 EUR per year for electricity. This means it’s worth to think about reducing the cost.

After reading this article you will know how to get the perfect light bulbs for your home — and you’ll be able to calculate if it’s economically reasonable to replace perfectly working light bulbs with more efficient ones.

Properties of a light bulb

When you want to replace a light bulb, you need to make sure that the new light bulb fits in the socket. There are some very common socket types:

  • E27: Edison Screw with 27mm diameter. This is the most common one for ceiling lamps.
  • E14: Edison Screw with 14mm diameter. Light bulbs with this socket typically have a candle-shape.
  • GU10 and G5.3: Typically used for spot lights in the kitchen

There are a lot of other sockets, but those three should cover most typical lamps.

Next, you need to think about which brightness you need. It’s measured in lumen and I distinguish those categories:

--

--

Martin Thoma
Plain and Simple

I’m a Software Engineer with over 10 years of Python experience (Backend/ML/AI). Support me via https://martinthoma.medium.com/membership