Keep the heat
All this heat we are experiencing this summer reminds me of something I've always wondered about. Why can't we save the summer heat for when it's cold in the winter. It seems so elementary. But apparently it's quite difficult, because it's being done in very few places.
Don Stephens calls it Annualized Geo-Solar Design and has actually designed houses where summer heat is stored under the house in an earth mass. The earth mass needs to be above the water table and insulated or kept dry some distance out from the house.
Another way to store summer heat is in saline solar ponds. Here's another explanation (scroll to the bottom of the page). And Mother Earth News had an article about it. Now this technology is mostly being used to generate electricity, but on a smaller scale it could provide heat for a house. Of course you would need some land for the pond and you would have to be next to the ocean or in a place that has a lot of salt like Utah.
How about storing hot water in insulated tanks in the basement. The water is heated by reflecting the sun down fiber optic cable. Well, this is just a theory. Maybe someone should try it.
Update: Thinking about these methods, I realized once the water was circulating, it would lose the heat in a matter of days or less, so you would have to have a separate tank or pond for each week or couple of days. I haven't seen this aspect discussed anywhere.