Being grid connected means that a solar photovoltaic system is linked directly to the available electrical grid or utility lines. A connected system comprises a photovoltaic panel or set of panels that directly convert sunlight into electricity. The size of the system dictates how independent from the grid it's possible to be. Grid connected systems need inverter to convert direct current into alternating current usable electricity. The inverter connects to the main electrical supply with a meter showing the number of generated kilowatt hours. Excess electricity can be sold back to the grid .