Why is it non-renewable energy is more used than renewable energy?

Renewable energy requires a large initial investment to bring online, and most existing power companies are still entrenched in fossil fuel consumption for their profits.

As long as there is coal to rip from the earth and oil to suck out of it, and profits made to distribute to politicians, and little public unity against burning these fuels, the status quo will be slow to change. 

Depends on where you are, and what is least expensive.

In the US ... Northwest region ... We use mostly renewable energy (hydroelectric), and always have.  The Southwest also uses a lot of hydroelectric energy, since they need dams for irrigation as well.

During some parts of the year, California generates up to 80% of its energy from renewable sources. But it varies because renewable sources can be unreliable: If there isn't enough wind or sun or water then it might not be there, and non-renewable energy has to serve as a backup.