From the doe website www.eia.doe.gov/emeu/recs/recs4a.html
Residential lighting uses less than 10 % of residential electricity and even
less of resdential energy use. Conversion of all homes to CFLs would save
about 32 billion kWh annually. However, total electrical use consumes about
4200 billion kWh annually so that is less than a 1% savings in electrical
energy and a much smaller percentage in total energy savings. A 32 billion
kWh savings is well worth while, but fundamentally this savings gets more
than eaten up by a single year's population growth.
CFLs have become the 'poster child' for energy efficiency, but in the long
run are miniscule in their effect. The one efficiency item that can really
make a difference is a high mileage vehicle versus the 'average' U.S.
vehicle (REAL fleet average under 20 mpg).
The cost factor of CFLs is about break-even (versus incandescents) taking
into account 'real-world' lifetimes (I assume California prices are
subsidized by your taxes--so you are still paying $2-5 per bulb). [I had a
zero lifetime bulb--first CFL I bought was dropped trying to get it into a
lamp--it didn't fit anyway.] My problem is that our house has about 20 65W
floods--most on dimmers. The CFL equivalents take 2-3 minutes to come up to
full brightness, and dimmable versions are way expensive.