Installing and maintaining solar panels costs a lot. Perhaps the businesses found that not profitable.
In Hong Kong, we have a "install solar panels on your roof" project, and the electricity company buys the power you generate at approx. 5x market price. It sounds great at first, but people quickly realized installation and maintenance cost so much, you can only get back what you paid for after 10 years.
This may not be relevant to the discussion because we are talking about big space, and HK houses are small area-wise.
Hell yeah Hong Kong film reference