Lightbulbs, how efficient are they, how long do they last compared to what is stated on the box?
I’ve created a video that is basically an easier way to look at this article. The details and links are the same as this written version, but a lot of people find watching easier to understand than the reading.
Also, underneath are the links to the actual article, so that you can read at your leisure etc. They’re in pdf and word (zipped) versions.