Solar thermal has some distinct advantages when you start talking about really big instillations. Especially when considering power storage, molten salt systems can store heat and allow the generators to keep working even at night. Much cheaper than batteries at very large scales.

Thermal solar systems are generally very efficient when the goal is heating something, not just generating power. So say, you want to run an ammonia plant without burning natural gas, or if you want to melt down metals for recycling. There are so many industrial applications where it’s a better way of doing it than using an electric heating element.