Solar panels generally raise the value, as the running costs of the house are significantly reduced and the system may even provide a long-term income stream. Nationwide, the average home value is 15 percent higher if it has a solar energy system. However, it's important to note that an increase in home value typically only comes with solar systems that have been purchased with cash or a loan; leased solar power systems generally do not add value to a home, as they are someone else's property attached to the house.