If you have any tax liability (have to pay any taxes), you are eligible for a dollar for dollar federal solar tax credit. This credit pays for one-third or 30 percent of the cost of a solar system. Most solar electric system components last/produce electricity for 30-40 years and solar panel manufacturers offer a 25-year warranty on their product. Further, if you select a reputable solar installation company like DC Solar Electric, we’ll stand behind the system and our craftsmanship for 25 years as well. The average payoff for a solar electric system is five to seven years.