Some incandescent technology might come down the pike to produce light
efficiently - isn't the sulphur lamp an incandescent lamp?
--


There are various technologies to improve the efficiency of incandescent,
I'm sure something better will come along eventually.

The sulphur lamp has long been discontinued. It isn't incandescent anyway,
it used a magnetron to excite sulphur inside a globe, it was noisy, not very
scaleable, and the light apparently was greenish, though I never saw one in
operation.