Practically all life on earth depends on the sun's energy. If our Sun were to disappear in this very moment, well we would go down with it in a joy (well that is if we're mentally unstable). Without the energy the sun gives to our planet, harvesting crops, enjoying the heavenly weather summer and spring and also other seasons bring us, would be impossible. Thus over the years people have considered solar energy more than ever before and have decided and also took action into harvesting this infinite source of energy. In numbers, less than 0.1 % of our transportation, power and heating energy comes from the sun, but given the advances of technology no we are able to use this energy more efficiently and thus render ourselves and our children cleaner environments to grow up in.
This type of energy can be used in many ways. For example solar panels is the most widely spread equipment to gather the sun's energy and produce power from it and other forms of energy. You can also use it to heat up your home converting it to thermal energy or to electricity, of course, with adequate equipment.
But the main drawback of this type of energy is that it is weather dependent. Now the place where you live on the planet can really make a big difference. If you are likely to live in a country with just one season or two where the sun is always in the sky, then you can consider yourself very lucky for you will be able to use this method to gain a lot of energy for which you won't have to pay a dime. The only thing you will be paying for are the panels, which, truly can be expensive depending on their quality, but the final result is priceless and you will never have to pay the electricity bill in this lifetime.
But even though this type of energy is so environmentally friendly to harness and it can really make you declare your house energy independent most people do not consider it for it is very expensive to begin with. Why? Because there isn't too much competition going around on it and the government won't allow the people to have their houses covered in solar panels for this purpose.
All things considered, solar energy may be an alternative but one that's far off into the future.