So I use a solar collector on my roof to collect the sun's heat. It uses the heat to heat my water. Cold water flows up to my roof through pipes and gets heated in the collector. The hot water flows down through other pipes into my house so I can take a hot shower or a bath.
Most people use electricity or natural gas to make hot water.
But if you live in a place where it's often sunny, you have probably seen solar collectors on people's roofs. The next time you go for a ride somewhere, look at the roofs as you pass houses and buildings to see if they have solar collectors on them. Solar collectors collect the sun's heat. You'll be seeing a lot more solar roofs as you get older. The President of the United States has promised to help put a million solar collectors and solar panels on roofs by the year 2010.