For homeowners, the cost of solar panels and installation has been falling precipitously in the last decade. Solar panel costs have reduced by more than 75% since 2010! Today it is possible to install rooftop solar panels for roughly $2.50 to $3 per Watt before tax breaks and approximately $2 per Watt after tax break. Depending on local energy costs, this roughly equates to 10-13 years return on your investment. Since solar panels typically are guaranteed for at least 25 years, this amounts to around 12-15 years of free energy for homeowners!