Student or Learner
There are some special types of lamps that use less electricity. What do you call them?
If you go to a lamp shop, you ask for SL lamp or light bulb which is a fluorescent-type light bulb, capable of energy saving up to 75%.
not a teacher
The current rage in the USA is the CFL (Compact Fluorescent Lamp). Many CFLs are designed to replace an incandescent lamp and can fit in the existing light fixtures formerly used for incandescents.
See Compact fluorescent lamp - Wikipedia, the free encyclopedia