Knowing how long a solar PV system lifespan is a very subjective matters as it might involve devices from different manufacturer and different quality been assured. However, how long of each component last depends on its warranty.
Warranty
A warranty is a promise from manufacturer or seller on the product that the quality or lifespan of the product will be met, and in (stated) circumstances if the product doesn’t met the condition of the warranty , it usually can be returned, repaired or replaced. Most warranty covers one to five years while some may extend up to ten years. If a product have long warranty, it is usually assured and giving a peace of mind to the end user who is using the product. Warranty can be voided if unauthorized tempering or unintended use of the product.
Some cases there is specific terms as such full warranty and limited warranty been used.
Full warranty will required the manufacture or company to repair or replace the faulty product that is within the specific warranty period. At times it will have a small clause that it cover the manufacture defects and may not include the normal wear and tear of the product. It can come with variant of lifetime warranty where the “life time” will refer as as long as the owner owns it or the product until it is discontinued by the manufacturer.
Limited warranty usually means the warranty coverage on specific parts only, not including the labour charges and other charges when repaired. Commonly are like motors or inductors etc. Usually limited warranty is longer duration and only involve very specific and critical parts. Hence it is important to read at the fine print of the manufacturer manual to understand its warranty terms.
Inverters, chargers, and battery all have different warranty period. Usually inverters have one year to ten years warranty depends on manufacturer.
Solar PV Panel Warranty
As for solar PV panels, the warranty is usually longer than any other standard consumer electronic products. Solar PV cells do degrade over time, but rather at a steady rate. There is solar PV panel manufactured more than 40 years ago and are still functioning, but efficiency of the cells output reduced.
Since solar PV panels is a multi-decade investment that can drive long term value, hence it is important to have a close look at your warranty. In solar PV panel, there exist two type of warranty : Product or equipment warranty and Performance Warranty.
Product warranty (or limited product warranty) will cover device failure due to manufacture defects within a specific duration upon installing, and this type of warranty can differ depends on manufacturer, some offer five to ten years of product warranty. The specific type of damage is depends on the terms, which may not cover user error that cause the panel to fail prematurely.
Performance warranty (or limited power warranty) in the other hand, is a guarantee based on the solar PV cells performance. In most cases, it means a guaranteed electrical production, usually at 90% of rated power output by 10 years, and 80% of rated power output by 25 years (all based on standard test condition). If the solar PV panels degrades faster than expected, then depends on terms, you may get it repaired or replaced.
Comparing product and performance warranty, if the solar PV fails or non functional, it falls under product warranty, however if the efficiency falls below the performance expected but still functioning, it falls under performance warranty.
Take note on imported items as certain products may require to ship the item back to the original manufacturer in order for the repair or exchange to be done, which the end user will bear the full cost of shipping.
The Solar Warranty Debate
There is also debate on solar warranty that some may not be aware of. Solar companies offer long warranty to give peace of mind, but there is a cache and strict manual on installations criteria to be follow, in order for the warranty to be valid.
- Only use authorized Solar Installers and certified technicians to handle the delicate panels during installation and repairs.
- Appropriate sizing of the solar modules. Having too many panels will risk higher than factory rated voltage and current passing the panels and risk of premature failure. Authorized solar installers will know the proper way to sizing your solar PV system.
- Make sure your panels have proper ground and grounding. Having solar PV panels install on soft uneven non-reinforced ground is a risk of voiding the warranty. Proper Grounding of the panels is important as stray surges from a lightning storm may damage your panels.
- Make sure you have correct clamps and rails been used with your panels. Wrong clamp and rails may cause structural damages and galvanic erosion, which leads to early equipment failure.
- Having solar PV panels installed in high salt and chemical environment, e.g. chemical factory or near the salt water sea, may void your warranty due to corrosive nature of chemical and salt water. Check the manufacturer warranty terms for more details.
Even if everything is done correctly, make sure you have your panels from a reputable company or manufacturer. You will be surprise that how many solar PV company had mushroom up during the past decade during the solar hype. We never sure how many will still exist after acclaimed 25 years of warranty.
Big well established companies that already stand the trial of time that had been producing diversifying of consumer electronics for more than 50 years are at a better stand and will have more certain will still in service 25 years later. (yup, some major well established consumer electronics company already join in the solar hype.)
Some company will have their panels covered by attached insurance, so that even if the company fails and ceased to exist later, the warranty period is still been covered by the insurance.
So will a imported solar PV panels that have no warranty or limited 1 year warranty be a bad choice ? It depends. These cheap panels still produce adequate power and can be get at a very low price. It may still last a decade or more and you will still get your return somehow over time, but such panels is usually not worth to be repaired (shipping cost and replacement cost will be over the price of getting a new panels.) – these also applicable to any other low cost third party electronic products, where you sometimes don’t care if there is warranty. Bad for the nature though.
Another points to wonder. As solar technology had been advancing over the ages, newer technology with higher efficiency panels are rolling out every year, prices of the solar cells are dropping every year, over time you can actually found cheaper buying new panels instead of repairing old one. This makes everyone to ponder, will spending extra future proof your investments ? well, only up to certain extend. Even if a CRT television is strapped with a 100 years warranty, it still makes no perfect sense, as after two decades of its commercialize availability, it becomes relic of the past, replaced with better quality and cheaper television with newer technology of LCD, LED, OLED etc.
Installation Warranty
Installation warranty is depends on the company that fix the whole solar PV system. Some company will offer 1 years to 5 years of warranty depends on company. It will give you peace of mind.
Installation warranty is important as you will know who to approach when issues raised. You will be certain that the next person who attempt to repair your expensive solar PV system is from the same company that knows the system well in and out. Depends on the terms, Some will cover the full cost of the onsite repair works and some will charge extra for workmanship but offer free exchange and replacement of devices.
It is to be noted that sometime the company hired third party for installations , which usually have lower installation warranty coverage. Higher installation warranty will be offer by the company who have owned authorized production line to marketing to installations, but usually comes with higher upfront cost.
Remember that if you call another third party installer to your still-in-installation-warranty solar PV system, the original installation warranty will be void if found been having unauthorized tempering around.
After the installation warranty period, you can have the choice of having the same company to continue maintaining your system with bearing of full cost, or you can have other third party at your disposal after understand the risk. Remember, Solar accredited electrician is always more expensive than normal electrician.
Know what can fail in your system
Knowing what can fail in your system will prepare you better in optimizing the lifespan of your system. It is applicable to most of consumer electronics devices too.
“whatever will go wrong, will go wrong” is one of the famous Murphy’s Law. The life span of any items will last unless something goes wrong.
Even those that guarantee a maintenance free system is still worth to have a minimum visual inspection every 6 months or yearly. You still can alert the respective services when you spot any abnormally in your system, before the damage becomes extensive.
Solar PV Panel
What can go wrong with Solar PV Panel ?
The solar PV panel consist of supporting frame, transparent front tempered glass, solar PV cells, Supporting back panels behind the solar PV cells.
Supporting frame can goes rust and degraded over time, especially on place and forget roof top installations. Most of current frames are made with anodizing aluminum frame that last for many years down the line, but placing another metal or material just in contact with aluminum can cause galvanic erosion overtime. In certain frame that have poor drainage, extended moist accumulation can affect the edge of the frame. The effect ? weaken frames that cause leakage of water to the solar PV cells.
Even the front tempered glass is tough and can stand years of sun and rain, but other uninvited particles can have effect on the glass, such as sand and dust. Most of the time the surface is self clean with rain water, but in area prone to sand storm, hail and heavy rain storm, a frequent visual contact with your panels is a better measure as you never know when too much sand storm had roughen your glass surface or unwanted flying debris had hit your panel causing micro cracks. In area that is very moist and having constant rainfall everyday, sometimes make sure there is no moss growing on the panels. Take note of effect of partial shade. A routine half yearly check on the panels and checks after a heavy sand storm or rain storm will suffice to detect any failing panels.
Solar PV cells are sandwich tightly between the front glass and the back substract. A good panel will ensure it is air and water tight. However in case of faulty or poor panels, air and water can sip into the Solar PV cells causing unwanted oxidation of the cells and its electrode conductor, causing increase in resistance and reduce in performance. Observe for any new artifacts, spots and rust across the panels in order to know which is the failing panels. If hot spots occur in your panels, it can cause localize heating of the particular cells that can damage the glass and back substrate. Hot spots are not to be ignored as it affects the efficiency of the whole panel as hot spots indicated a faulty cells, weaken soldering or abnormal high resistance area.
Similiarly to the back of the solar PV panel. inspect for any cracks due to heat and cold cycling over the days. Look for burn marks which indicates areas of hot spots.
Wires and Connectors
Wires are not place and forget items. Outdoor wires can withstand heat and UV punishments , but do check them yearly to detect any faulty wires and connectors.
Note for abnormal cracking, peeling or flaking of the outer insulator. Especially when wire are in tension, as such on a tight bend or been tout tightly, the wire can fail over time.
Connectors are not to be missed. Check for any sign of wear and tear due to heat and UV damage. Check if connector is still holding tightly. Check if there is sign of failing connectors such as expansion and cracking due to leaking of moist causing rust in the internal metal contact. Remember each connectors is a point of failure. Failing connectors will increase resistance and reduce the overall efficiency of electricity transfers.
Miniature circuit breakers
The miniature circuit breakers (MCB) will hold important function to stop a current flow is the current flowing it exceeded the rated current allowance.
Nothing much you can do from the circuit breakers maintenance, but still worth a visual inspection. You will never know when one of the circuit breakers to a single PV panel been tripped off until you realized it after some time.
A tripped circuit breaker will means there is abnormality in the current flow. Check the device connected to it, may it be the solar PV panels, inverters or batteries. Frequent tripping of the breakers will mean you may have the MCB with rated current lower that what your device is producing/consuming, or you have a faulty devices that shorts out. Faulty devices requires prompt action to prevent short circuit and further damage to the system.
You will never know that you had switch of the MCB to particular panels during last maintenance and only realizing it after some time when wondering the efficiency of the systems starts to degrade after last maintenance.
Inverters and charge controllers
Inverters (all types including grid tie and off grid) and charge controllers have dedicated electronic component inside. The main component is the capacitor and power regulating Mosfets.
Capacitors have function to store small amount of electricity (Capacitance) and have its role to smooth out small surges, coupling and decoupling, power conditioning, oscillators, signal filters etc depends on types. Capacitor have a limited life span or mean time failure rate. Cheap capacitors (older types) will leak or burst caps over extended use in unfavorable environment, over voltage or over current. Hence make sure the environment that these equipment working under is not poorly ventilated or extensive heat, especially hot summer days.
Also ensure that the maximum voltage (Voc) and current (Isc) from the solar PV panels does not exceed the capacity and the limit of the device connected to it, as such in very cold climate, the voltage output from the panels may exceed what was rated on the panel (which only tested at standard test condition).
Power regulating mosfet are one of the important components in regulating the correct voltage and current in the circuit. The higher the power been transferred, the higher the current, the higher the heat been dissipated by the mosfet. These delicate semiconductors is usually coupled with a heat dissipating heat sink to prevent overheating and “burned”. Make sure your equipment is well ventilated. Make sure your fans into your system is not blocked, or filled with dust bunnies.
Higher power inverters and charge controller may feature a external heatsink , these heat sink need to be maintained for optimum heat dissipation. Any dust or oil or grease on the surface may reduce its performances. Ensure the ventilation fans on these devices are still working after years of services as some dust may trap in the shaft and bearing reducing the efficiency of the fan motor. At least yearly or twice a year cleaning of the ventilation fan blades to prevent thick coating of dust at the fan blades.
To prevent shock during these device maintenance, always make sure the system is shut down via the mini circuit breaker. Actively functioning solar PV panels in long series can have enough voltage to cause a shock to the naked hand. Occasionally the capacitors in these device still hold a charge after disconnect , hence handle all these devices with care. Grid tie inverters must be disconnected from the mains when servicing.
Since these devices are delicate with risk of shock hazards, make sure you know what you are doing or get a profesional certified electrician to do the job, especially if you have a very huge solar PV array that rated beyond kilo watts of energy production. Improper maintenance can also void your warranty.
Battery
Battery is a very important part of a off grid solar PV system and hybrid solar system. These bulky battery is also not to be place and forget as it will determine how efficient it can hold your energy that is been generated. A battery that don’t hold a charge well will rather means no battery at all. Poor battery maintenance will lead to shorter lifespan.
Most battery nowadays are going into maintenance free. But they are not to be forgoten. Overtime dust and oil can cover up the battery outer casing and reduce its effective heat dissipation while in operation.
Overtime sulfaction may build up in the lead acid battery, causing reduce in battery performance. Check if your charge controller have function to desulfact the sulfact crystal layers or some you need a dedicated desulfactor to do the job.
Sulfaction and crystal formation also may form around the contact between the cable and the battery terminals. Visually inspect all connection around the battery.
It is also a good practice to inspect the whole compartment once a year as you never know what critter will be nested around these comfortably warm compartments, between batteries, at the edges etc. Check for any visual damages or leaks. Yes, if battery is operated in sub optimal temperature, it may expand and leak. A swelled up battery is a sign of battery failure and need to be replaced.
In cold climates, also make sure the compartments that hold the battery have enough insulation to prevent freezing of the water inside a lead acid battery , especially water in battery are prone to freeze when deeply discharged.
Other maintain ace of a flooded lead acid battery includes checking its battery water levels and specific gravity.
Maintaining the Load
Most people forget that other than maintenance of the solar PV system, you also need to have routine maintenance of your load.
Your load can be of any appliances, from lighting, to motor, to refrigerator, to television, to mobile devices etc. Although initially you may have a good plan on a perfect ecosystem of devices. But most will forget that aging devices will draw more power from system, especially motorized equipment. After 10 years of content with your current build, you may never know what will be the next devices you will add to your system. By that time, your solar PV system is not get any younger. Over time, imbalance will stir up in your system and causing extra strain to the existing system.
Make sure obsolete or faulty devices are removed from your system and every new devices added to the family need to be considered on the strain of the system. At least have a calculation and checklist to check all your connected load once a year. You will be surprised on how much had been change after the long 25 years solar PV panel warranty ends.
Your Roofs
It is true that you can have a solar PV panel working on your roof for few decades, but it is still worthwhile to check your roofs (for roof top installations) for sign of failing roof before leaks sets in and weaken the underlying beam structures.
Depends on quality and material of your roof, sometimes the solar PV panels live longer than your roof will last, although most roof material currently are build to last.
This brought to the question, did you install your solar PV panel on a old aging roof ? if it is so, either have the roof changed before installing solar PV panels or be prepare to have a roof change when the solar PV panel still in service.
Changing a roof with solar PV panel is not impossible, thanks to the quick release and fittings that is available, but it will still be troublesome for most.
Check if there is leaks on your roof once a while, and have a prompt action even a small leak on the roof.
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