
There are a number of factors that determine the cost of a solar panel system, such as the system size, equipment used, roof characteristics, labor involved in installation and location. According to Energy Sage, solar panels in the US cost about $20,474 for a 10 kilowatt (kW) system, which will give a large family home adequate power. On average, it takes seven to eight years to see a return on investment. But many countries, states or even local authorities offer subsidies, so you could break even much sooner.