Report shows cost of de-installing a solar array when replacing an asphalt/shingle roof could be as high as 35% of the total system cost.
The lifetime cost issue of solar -- and one that many people never consider -- is that rooftop PV systems may have to be removed and reinstalled if the roof needs replacement or repairs, which is almost a certainty with asphalt/shingle roofs. While PV systems typically lose a small portion of their potential output (less than 1 percent each year), the systems can operate for decades longer than the typical residential or commercial roof (10-12 years in Georgia). In other words, roofs are likely to be replaced atleast once during the typical life of a PV system.
According to a report from GRIST.ORG, reinstalling a residential rooftop PV system could cost $6,250 or 25 percent of the installed cost of the system. In our investigation, we found that moving residential PV systems to accommodate a roof replacement could cost as much as 25 percent of the initial system cost (and over 35 percent of the net cost after the application of the 30 percent federal tax credit). Moving systems on a commercial roof was less expensive, on the order of 15 percent of initial installed cost (around 25 percent of the system cost after the tax credit).
The point we at Energy Roofing Systems are trying to make is that it simply doesn't make sense to install solar panels on top of a shingle/asphalt roof. As this report shows, it may cost anywhere from 25-35% of the initial cost to have the system de-installed when the time comes to replace a shingle roof.
Don't throw away your hard earned money. If you are seriously considering going solar, think it through, do your research, and understand that it makes more sense in the long term to replace your roof in the short term.