Solar panels do not go bad and very rarely are they faulty or break.
Average solar panel degradation.
According to a photovoltaic degradation rates study published by the national renewable energy laboratory nrel the mean average degradation rate for solar panels is 0 8 per year 25 years to 80 with the median falling to 0 5 and 78 of all installations examined showing less than 1.
For the above example a 0 8 degradation rate means that in year two your panels will operate at 99 2 percent of their original output.
No degradation in any of the other equipment consistent insolation values and weather year to year etc the annual degradation is the percent difference between each year s production.
On average solar panels degrade at a rate of 1 each year.
According to an analysis by the national renewable energy laboratory nrel some premium panel manufacturers offer degradation rates as low as 0 3 per year.
However a study conducted by the national renewable energy laboratory nrel shows a more accurate picture of solar panel degradation.
That s backed up by the solar panel manufacturer s warranty which guarantees 90 production in the first ten years and 80 by year 25 or 30.
Solar inverters and solar batteries will need replacing within the 25 year solar panel lifespan.
Properly maintaining your solar panels will help ensure they last longer.
By the end of their 25 year useful lifespan they will still be operating at 82 5 a slightly more durable panel with a degradation rate of 0 5 will likely produce around 87 5 as much electricity as it did when it was first installed.