For on-grid installations, solar panels can act as more than a supplement to your on-grid power supply; During periods where your solar panels generate excess energy (more than your household needs), you can wind back the power meter by pumping energy back into the grid. Recent legislation has forced the power companies in over 42 states to pay you for any excess energy you add to the grid. If you'd like to benefit from a system, you'll need to purchase a Synchronous Electrical Inverter. A Synchronous Inverter helps you maximize the output generated by your photovoltaic array by converting the direct current generated by the panel to alternating current, whose voltage can be modulated by the power company's transformers and piped into the grid. On-grid solar panel systems with a Synchronous Inverter can even generate a little income during months of extraordinary solar insolation. During months of subnormal solar insolation or solar panel disrepair, you can rely on the power grid.
Every month, the utility company will log how much power you've generated and if you generate more than you've consumed, the a credit will appear on your energy bill. Typically, at the end of the year, if there is an existing energy credit on your account the power company will pay you back for the electricity generated by your solar panel installation. The price you are paid is generally not the same rate as the price you pay for electricity - the power companies only pay you at the rate it costs them to generate electricity, not at the same commercially marked-up rate at which you buy electricity. Because solar panels are generally more costly per watt with regard to the grid-based systems, it is difficult to generate a profit on the energy you generate, but selling power back to the power company is helpful for two reasons:
Even if you don't earn much money back from the power company, on-grid installations are beneficial in seasons of low solar insolation due to malfunctioning equipment, inclement weather, or other factors that may dip your power generation below your monthly energy needs.