I was a young man, but I saw what was going on. All of the little things that can be done around the house to conserve energy help in the short term. But the solar system is really the only thing that people can buy that is going to pay for itself and then continue to make money for them for a long time. You can buy all of your energy up front while you are young and are working and can afford it. Then you can go into retirement not having to worry.
Solar energy can heat pools.
It can heat hot water for the house. And, it can provide the electricity for the house.