The whole thing boils down to gaining competence,and you get that while working for others.Most persons just want to rush into making money,it does not work that way.Gaining more experience on what you already know over time will greatly increase your chances of being more skilled at what you do.Honestly speaking it depends on how you go about it. Solar power is now one of the leading energies. Everyone wants to have a solar system instead of a generator. Even the ones with generator still go for solar system. Working on your own, you might not actually earn much unless you are lucky. You can apply with companies that are incharge of doing this kind of job, and join their field agents