Output Efficiency of solar panels
Solar panels are a revolutionary discovery. They reduce pollution in turn helping to lower the impact on our planet by absorbing the sun’s free energy for us to use, but they aren’t quite perfect. If you went for the cheapest panels possible, from a brand that is not very well known, like anything you can end up getting what you pay for.
On the other hand, if you invest in reputable brands with a long track history of happy customers that include warranties to cover the expected life of the panels, the odds are you’ll get the most value and longevity for your investment.
Most of these reputable brands (some we use are MSquare, Enphase, Jinko, Q Cells, LG), their panels will slowly degrade in output as they age; this is by design and cannot be changed with the current technology available. These reputable brands will offer at a minimum warranties to guarantee the panels will have at least 80% of their nominal capacity after 25 years. Some can offer more, but will incur additional cost.
Whilst the warranties will cover a capacity of 80% after that timeframe, it is difficult to predict just how much solar panels will degrade so it is an educated conservative amount but is a good indicator as to the capacity after 25 years. What this does reiterate is to choose quality suppliers and reputable brands, as from our experience it is evident that the cheaper competition tend to fail prematurely, lose their output a lot earlier and the warranties do not cover as long.
SOLAR PANEL DEGRADATION CAUSES
As solar panels slowly decline, over the years tiny cracks or fissures develop in the silicon solar cells which lead to deterioration of the electrical connections. The main contributors to panel deterioration are:
Thermal Cycling: As temperature fluctuates so too does the materials expand and contract, resulting in pressure being introduced to the joins and connections and deterioration over time. The temperature changes described are thermal cycles between night and day, overcast and sunny days, rain, etc.
Dynamic Mechanical Load: This is a complex term that is basically referencing to flex caused by wind. Usually when the panels are installed correctly and clamped to the roof, there will be minimal flex, but it is still a factor which will contribute to overall degradation of the panels.
Humidity: The climate in Australia means a combination of humidity and high temperatures can be hard on solar panels. Low quality products can quite literally fall apart and breakdown as the adhesive that holds them together dissipates. Another issue that can arise is PID or Potential Induced Degradation, which is a form of electrical failure as a result of electrons ending up where they shouldn’t.
UV damage: The quality solar panels from reputable brands tend to have this covered with UV blocking technology, but some panels that aren’t made to high specifications can start to turn yellow in the sun and eventually come apart over time.
Freezing: This can be a problem if moisture enters joints or seals, and the temperature happens to go below freezing, the moisture can turn to ice potentially expanding which could contribute to deterioration. Fortunately in Australia, this isn’t really a problem worth worrying about. If you live in a location where frost occurs often, there are panels designed to withstand these conditions.
MOST SOLAR PANELS SHOULD EXCEED THEIR PERFORMANCE WARRANTIES
Solar panel companies generally don’t want to be spending money to replace panels that don’t perform as they’re expected to, so they invest in research and development so that the products last as long as possible and that the warranties align closely to their performance life span. For this reason we can expect the panels to be overengineered to a point where they are more likely to extend past their warranty period, as the manufacturer would prefer this than fail earlier.
To find out more, get in touch with All Green Environmental Solutions today and get the best advice and price for your installation!