Thinking about solar power [AKA diurnal thermo-nuclear]; Maybe one of the most effective things we can do to counteract global warming and ocean acidification is to store heat energy in rocks and bricks to be used for frying, steaming and baking food. The simplest way of doing this will be to use curved mirrors to focus the sun's heat onto hollow pipes. The air inside the pipes needs to be heated to about 250 deg C but that just means the mirror concentrator for each such pipe needs to be about 6 times as wide as the diameter of the pipe. My recommendation is that the collector pipes are held immobile and exactly parallel to the Earth's axis of rotation. This arrangement means that the mirror concentrators only need to move right around the pipe once every 24 hours. [The word "Clockwork" comes to mind.] A Stirling engine can be used to pump/blow the hot air along an insulated delivery pipe [underground for preference], and into the bottom of the insulated rock pile or brick stack. The oven will be whatever shape suits the baking style of the home and will simply be the top part of the insulated brick stack with thick tiles for floor, walls and roof. The door could be hinged, or sliding, or just some kind of insulated metal sheet. As can be seen, none of this is "rocket science" is it! Furthermore, something similar but with different dimensions and lower temperatures could be made for drying the washing instead of using mechanical electric energy guzzling driers like so many urban households do now.