Do British people use the word lightning conductor more frequently than a lightning rod?
As a British person, I would say that American people often use "lightning rod" when they are talking about a lightning conductor. This is usually mounted at the highest point of a building, and connected to the ground by an electrically conductive link of copper or other metal. UK and US building and safety professionals tend to talk about "lightning protection systems", of which the rod or conductor (often called the "air termination device") is one part. In figurative language, however, the term "lightning rod" meaning "someone who attracts criticism or anger that could be directed at someone else" is pretty common in the UK.