Solar One (California): Parabolic Trough Concentration

The Solar One pilot plant (1982–1988, Barstow, CA) used a parabolic trough system to concentrate sunlight.

How it worked:
- Long, curved (parabolic) mirrors focused sun on a receiver tube running along the focal line.
- Tube contained heat transfer fluid (HTF) (synthetic oil).
- HTF heated to ~390°C (735°F).
- Hot HTF generated steam → drove turbine → electricity (10 MW).

Solar Two (1996–1999) converted it to a power tower (heliostats + molten salt) for thermal storage. The site now hosts Ivanpah (power tower).