Perhaps the most notable finding from the report, which builds on a finding from last year’s edition, is that operational solar assets are continuing to experience higher than expected rates of degradation, with annual degradation in the field observed at around 1%.
It cites recent research conducted by both National Renewable Energy Laboratory (NREL) and Lawrence Berkeley National Laboratory, as well as kWh Analytics, as demonstrating that assumptions made in 2016 – that annually solar modules would degrade by around 0.5%, is outdated and underestimates annual degradation by as much as 0.5%.
kWh Analytics’ most recent figures place the median annual degradation for residential solar systems as 1.09% and non-residential systems at 0.8%. The report states that over a 20-year asset life, project degradation could therefore be underestimated by as much as 14%, resulting in severaly overestimated performance and revenue forecasts produced within a P50 model.
I just calculated the degradation on my panels that were supposed to have 0.75% degradation or less per year. My first full year was 2016 and compared to 2023 I am at 96.4% over 7 years…so a bit more than 0.5% per year.
Of course, this calculation is possibly suspect since the actuals vary based on the weather differences.
Is the degradation the result of the panels’ chemistry degrading or is it surface erosion and dirt accumulation, or both? How were the panels tested for longevity?
Light-induced degradation
~ Light-induced degradation (LID). Interaction between the crystalline silicon cells on the panel with the outside environment. LID can last days or over a week.
~ Direct light-induced degradation (DLID). Direct exposure to sunlight during the initial setup period can cause the electronics within the photovoltaic cells to warp or buckle from the heat. DLID can last a few hours.
~ UV light-induced degradation (UVID). Initial exposure to sunlight causes the crystalline silicon oxide on the surface of the panel to form a layer of boron dioxide that reduces its efficiency.
Potential-induced degradation
~ Unlike LID, PID does not necessarily affect every solar panel, but can happen if the different components, such as the photovoltaic cells and the frame, operate at different voltages. This disruption causes voltage leaks, reducing the amount of electricity the panel can send to the inverter.
Age-related degradation
~ Heavy rainfall, snowfall, ice, as well as high temperatures cause hardening of the crystalline silicon, frame corrosion, and cell contamination. Hail, ice, dust, and sand can also cause microcracks on the surface of the panel, and damage to the seal on the panel can result in water getting inside. Moreover, reactions in the semiconductor materials used in the cells can create shadowing that reduces the amount of light that the panel can convert into power.
My understanding of the article was that the solar plants are underperforming more that they are suppose to. So they lied about how good they were. wasted resources. You’re saying standard power are subject to the vicissitudes of life. We know that. I am not comparing theorectically perfect to sub-standard.
Nobody ever claimed that solar was perfect except you. Solar panels are not easy to repair to up their performance. Thermal power plants have ongoing costly maintenace and upgrades to keep their performance.
An examination of the facts do not support that claim, at least for nuclear power. If it were true, we would expect the annual output of nuclear plants to degrade over time. This is not happening, based on the published generation data from the EIA.
For example, in 2001, the Palo Verde Nuclear Generating Station in Arizona produced 28.7 million megawatt-hours (MWh) of electricity. In 2023, the plant produced 31.5 million MWh. Generation actually increased over that time, instead of decreasing.
Another example…
In 2001, the North Anna nuclear power plant in Virginia produced 13.1 million MWh. In 2023, the plant produced 15.8 million MWh. Again, electricity generation increased over that time.
Another example…
In 2001, the Braidwood nuclear plant in Illinois produced 19.7 million MWh. In 2023, the plant produced 20.1 million MWh. An examination of the trend line shows generation to be fairly constant over those 22 years.
If nuclear plants degraded, say 1/2% per year, then we would expect output to decrease by a total of 10% between 2001 and 2023. This has not happened.
The owners of nuclear plants perform regular maintenance, usually during the refueling outages, to keep the equipment in top condition. Sometimes that work involves replacement or major overhaul of large equipment items, such as replacement of the blades in the main turbine, or installing new steam generators. Such regular maintenance is done at every well-run power generation facility.
You are not understanding what I wrote. Nuclear power plants and fossil fuel power plants have expensive maintenance and repair efforts going on annually to maintain the performance of the plants. Solar panels do not have such maintenance and repair efforts because solar panels are not repairable to maintain their performance.
Here is a more complete summary of my panel’s performance
2016 100% starting after 7 months old
2017 98.9%
2018 99.3%
2019 96.7%
2020 94.8%
2021 98.8%
2022 97.0%
2023 96.4%
2024 (97.7% thru July)
You can see how the randomness of the weather causes variations much greater than the panel degradation. Comparing month to month I sometimes see 20-25% difference due to weather.
Dirty panels also can cause a few percentage loss and I see a lot of large installations (school parking lots with hundreds of panels) that look like they’ve never been cleaned. Of course the infrequent rain here in CA cleans them some.
I hose mine off 2-3 times a year after the rains have stopped.
I replaced my heater a few months ago, after 16 years. Yes, stuff does seem to keep getting cheaper. I was at a car show last Saturday, all Lincolns. It was interesting to look at the details of the interiors: the older cars, from the 60s and 70s, had high quality materials on the doors, from top to bottom, and elaborate trim. The new Lincolns that company reps brought to the show had cheap, hard, plastic below the armrests.
As commented before, wish I had a nickle for every person who came in my Radio Shack, and the first thing out of his mouth was “what’s your cheapest…?” That’s how USians roll. They want everything big and glitzy, but they don’t want to pay anything.
As I remember it…from all my parent’s cars, every one of them had a plastic dashboard that cracked from the heat up near the windshield after a few years.
My dad bought a brand new Packard Clipper 1953. After a few months the upholstery started to wear out. My dad was very upset and went to the dealer to complain. What was wearing out was the fabric cover over the real leather upholstery. It was removed and a beautiful gray leather appeared which lasted the life of the car. It became my hand me down car when it was 10 years old.
