Active solar is when you use more expensive solar panels and the like to produce electricity to either charge batteries or to power items direct.
I think one of the oldest uses of passive solar is to face your home towards the south when building (in the U.S.) as this has been done for many years. This gives you the most sun for the most parts of the day.
Solar tubes and skylights and good insulated windows provide good lighting in the home for most of the daylight hours. My daughter’s house has a skylight in an interior bath that you hardly ever need a light saving on electric. More of these in homes could be considerable savings.
Gardeners in this country and other countries have used the sun to dehydrate food at no energy cost once you build the initial equipment (and this is not expensive).
Gardeners have used greenhouses connected to their homes then the sun and plants heat the homes at no extra cost and with hours of enjoyment.
Collector panels at windows build up heat to be used in the home. These can be bought or built your self as plans can be easily found on the Internet.
Solar to heat water to run steam engines was popular at one time until a more reliable and cheaper source was found. But now with cost what they are this may return as a source of energy.
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