Why is solar thermal playing second fiddle to PV? - Low & medium temperature solar thermal In fact - CLIMAX
In Ireland in 2020, there were almost ten times as many solar PV systems installed as solar thermal systems, according to this report - https://bit.ly/3sDnayZ .
The story is likely to be similar across many other countries. This should be surprising, given that solar thermal systems have been commercialized much, much earlier compared to solar PV!
What could be the reason? Heating is as important to a household as is electricity, and solar water heaters achieved industry strength reliability decades back. While they indeed involve an upfront cost, so do solar PV systems.
Solar PV's relatively faster growth compared to solar thermal could be attributed at least partly to the way the key solar PV industry stakeholders marketed it, created awareness and also got their respective governments to do something about it.
Overall, the solar PV stakeholder ecosystem has been more aggressive in their business development than that of solar thermal.