After the last post a few questions came up about solar panels and the risks involved in such a large purchase (not just from my wife). So without further ado, here’s some info about warranties, lifespan, durability, and maintenance.
Warranties, Lifespan, and Degradation
Solar systems are comprised of a few major components – the panels, inverters, and install.
Each panel manufacturer has slightly different warranties but I’m going to focus on Itek given they’re made in Washington, which gets the best state production rebate. These panels are covered by a 12 year warranty on the failure of the panel, glass, frames, connectors, and wiring. There is an output warranty as well, promising less than 1% output degradation per year for 25 years, with less than 20% degradation over the 25 year span. The panels can produce energy beyond that time but of course output will continue to drop.
Solaredge string inverters for example have a 10 year warranty, which can be extended up to 25 years. These units do cost a few thousand dollars today but its also reasonable to expect prices to continue to fall significantly as time goes on. Other firms use Enphase micro-inverters, the quote I expect to install has the IQ7 micro-inverter which includes a standard 25 year warranty.
Most installers also include a 10 year workmanship and service warranty – so any issues which require service will be covered for a decade.
Fortunately the NW isn’t subject to many of the conditions that could damage a solar panel – sandstorms, large hail, hurricanes, etc. Generally speaking a solar panel won’t get damaged by regular NW conditions, probably the most likely thing is a falling branch or tree, which would damage the roof if the panel wasn’t there – hard to judge which is more costly a repair. I also found my homeowners insurance will cover the panels for a small fee.
Maintenance & Monitoring
Largely solar panels are set it and forget it, but the panel needs to be clean-ish for optimal results. One of the great things about solar in Seattle is we have a self cleaning mechanism – rain. The rain combined with lower particulate levels than say LA, means less cleaning. The process is about the same as window cleaning and some firms will handle both for you. For most people an annual cleaning sounds sufficient.
The common inverter systems used (Solaredge and Enphase) have monitoring components so you can see output per panel (when using a string inverter with optimizer or micro-inverters), failures, etc. So no need to worry if something is broken and not producing power without you knowing about it.
Given the equipment and labor is covered past the ROI period solar, there’s few environmental concerns with durability, and maintenance in the NW is low – a solar system is a fairly safe bet to have a long life and not to have surprise costs exceeding the savings.