Hugely. A few of the main factors that will determine your payoff time:

- Subsidies. - Cost of labour. How much do you need to pay to install the panels? - Your energy usage patterns. If you use a lot of energy when the sun is shining, your panels will pay themselves off faster. - Cost of transmission of energy. How much does it cost to get the energy from the generator to you. - Cost of energy. How much it costs to generate energy where you are. - Location. Proximity to the equator, annual sunshine hours, shading, panel angle.