What is the lifetime of a solar power system?
All solar panels have a claimed 25 year output ‘warranty’. Ironically for most panels this does not mean they will last, or are warranted to last, 25 years. Not all panels are the same. Some have both output and product 25 year warranties. Quality panels can be expected to perform beyond this, perhaps 30 years or more. Conversely cheaper, budget panels are highly unlikely to reach 25 years and still be performing adequately.
A solar panel is relatively a simple device with no moving parts; the key components susceptible to failure are the solar panels and inverter. However, high quality products tend to have long lifecycles which are reflected in the long product warranties available, particularly for solar panels. Cheaper panels, with lower quality silicon cells, less UV stabilized backing sheets, cheaper sealants and framing can deteriorate more rapidly. Also solar panels which are exposed to wind, sun, and fluctuating temperatures will deteriorate each year and produce less electricity. With quality panels this deterioration is slow. Generally cheaper panels deteriorate much faster, often at double or triple the rate of quality modules.
Solar panels on a string inverter only perform to the level of the lowest performing panel. In a string of say 13 panels it only takes one to have a performance issue to substantially lower the generation of the other 12 connected to it. The low quality assurance on cheaper panels will frequently mean the ‘weakest link’ panel is very poor performing and this will be reflected in the very low output of the whole system.
LG’s warranties predict an average of 0.3%-0.35% loss of power each year after the 1st year and thus, at the end of the 25 year output warranty period the solar panel is warranted to only lose 10% of its initial power rating. This means a high efficiency LG solar panel producing 375 watts when new will in 25 years produce 340 watts or more (or else you get a new free panel). Lower quality panels, starting at 315 watts when new (well below LG's output after 25 years operation) will degrade to around 230-252 watts per panel output after 25 years (if they are still working). A full 100 watts less than LG. For cheaper panels the rate of degradation is much faster, this is particularly true of “P” type or PERC type panels which are more susceptible to high temperature degradation. In most cases cheap, low quality panels will never actually last 25 years. Cheap Shoddy Solar Panels.
Inverters are complex electronic devices; having to constantly adjust output power therefore they are more susceptible to failure. Cheaper inverters tend to have a higher failure rate in harsh Australian conditions. Many do not last 5 years. Quality inverters are more expensive but generally will last in the range of 10-15 years. Many manufacturers now offer warranty extensions of 10 years or more.
Although the cables, safety devices and mounting systems are less influential, the use of poor quality materials can lead to premature system failures and in cases of non-branded plugs and cables complete system failures have occurred. Therefore, it could be argued that in order to get a decade of low maintenance solar electricity you should buy quality solar panels, quality solar inverters and ask for quality balance of components. LG is confident that our panels will give you years of reliable functionality.