In Silicon Valley, it almost never rains during the months that air conditioners are used. There are many acres of commercial roofs here, soaking up the heat of the sun.
I would think that this heat would be a significant factor in the HVAC requirements, reducing the need for heating in the winter and increasing the need for air conditioning in the summer. But maybe that’s not so, for example, maybe the roofs are excellently insulated from the interior.
It would be great if those roofs were using photovoltaic panels to convert the sunlight into electricity, but until then I wonder why facilities in the summer don’t just roll out cheap reflective tarpaulins coated with the same material car owners have propped up behind their windshields/screens in the parking lots below.
This seems so obvious that I think there must be some reason why it isn’t done. But what? If you know, please leave a comment. Thanks!