In recent years the price of solar panels has decreased by 50%, this together with state benefits, federal ITC incentives and attractive financing options make solar energy a viable option economically and socially. According to the Zillow real estate portal, using a solar energy system increases the value of the property and sells 4.1% faster than another home with identical features without panels. One of the reasons why homes with these systems are sold better and for a greater value, is because they are going to mean considerable savings in energy consumption for new tenants. Houses with solar energy have other characteristics that are difficult to quantify, but very valuable, such as the energy efficiency rating, the optimization of energy use and an ecological environment.