Solar energy is now cheaper than coal and natural gas in most nations, according to an October 2020 report from the International Energy Agency
. Decreasing costs for solar photovoltaics (PV), along with efforts to minimize non-hardware costs
, help explain the increased solar capacity coming online to the electric grid.
But as solar continues to grow, in addition to the existing solar PV capacity in the United States, those panels will eventually reach the end of their useful life. What will happen then?
Most panels last between 25 and 30 years
, with many manufacturers providing 20- to 25-year warranties. According to a National Renewable Energy Laboratory (NREL) study, the average degradation rate for solar panels is .8% per year, with newer panels having a .5% annual decline. In other words, the amount of energy an array
can be expected to produce in 20 years will be about 90% (assuming a .5% decline) of what it produced when it was first installed. Although 30-plus years may seem like a long time, some panels installed by early adopters might be ready to come down soon.
The industry will need to start thinking about waste management solutions. Figuring out the most cost-effective way to deconstruct and recycle solar panels, which comprises glass, metal and silicon wafers, is still a question for the industry, as many are made with adhesives that can be difficult to remove. Although one solar company already has a module recycling program
, limited facilities exist, and that time to decommission panels will be here before we know it. One new California regulation recently re-classified solar PV panels as universal waste
, which could make panel recycling easier. That category changes how long the panels can be held onsite before being discarded and has fewer requirements for hazardous material testing.
As more builders consider installing solar PV
, understanding the full life cycle for major components such as panels and inverters will become increasingly important, given the sheer amount of equipment being installed.
Want to learn more about solar PV? NAHB's solar toolkit for builders
may be able to help you navigate the world of solar on your new construction homes.
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