The recent flurry of posts does not signal a return to the golden ages of towers of ilium. There never was a golden age. Maybe 1966 and early '67.
Residential solar could turn out to be a big thing. Most houses have appliances and a rooftop solar array is just another appliance. That it can be purchased on an installment plan is something that will appeal to many homeowners. Buying things on a credit is the first sign that a culture has become suffused with optimism.
Oil prices will recover.
There is no contradiction between the comment about residential solar systems and our continued reliance on petroleum.