There are two ways in which solar power can work. One of them is "solar voltaic", which is a form of solar energy that comes from the light itself.
Here the light is used to 'excite' particles held on the solar panels to encourage a current to form which is then 'transformed' to the correct format for use with household and other appliances.
The other form is "solar thermal energy", in which the heat of the sun is used to heat small tubes of water and then used to heat other objects such as swimming pools and spas.
Why is it So Useful?
The first and most obvious reason that solar power is so useful on a personal/business level is that it allows us to use energy completely free. Because the sun is so abundant and belongs to all of us, this means we can run appliances without it costing a dime.
At the same time, this means we are independent of energy providers and safe from power cuts or sudden increases in energy charges. The second reason is of course because it is good for the environment and this, in turn, allows us to use our various appliances as long as we want to and to remain completely guilt-free.
Finally, it's important to remember that fossil fuels take millions of years to form and so are finite. If we don't switch energy sources soon – well then we are going to run out of energy.