From solar dummy to expert

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Are you getting sick of all the different solar warranties, guarantees and insurances you get offered? Unfortanely, there is significant misrepresentation from all those industry players about what benefits an end customer receives. Here we try to explain various types of PV warranties and guarantees. Once you have read the information underneath, you can make decent decisions about your future solar plant.



Solar Module Product Warranty

This warranty is no different to the warranties you buy for typical household appliances. The industry standard is for brands to warrant that the modules “shall be free from defects in materials and workmanship” for 10 years. There is not really any trickery that is taking place here and it is standard pretty much across the whole industry. You can expect to see a few exclusions that state that they must be transported, stored and installed correctly in all of these warranties.

However, these warranties generally only cover the value of the module and not the cost of transporting a new one, replacing it, or production loss, they also exclude damage caused to person or property by the faulty module. These warranties are not designed for residential users and most brands are poorly equipped to deal with residential claims economically.

Thankfully, unless you have chosen the cheapest module on the market, solar modules very rarely fail completely. They are much more likely to slow down faster than they should and that is where the kWh guarantee (below) steps in to play.

End user verdict: If you chose a good installer you should get the coverage and service you require at little to no extra cost. If your installer has disappeared or used you for a quick buck you are most likely (and very sadly) on your own and can expect to be out of pocket. A good brand will be able to put you in touch with a local reseller, but the costs incurred are most likely to exceed the benefits in this case.

Solar Module Output Guarantee

A modules output power (or size) is determined by how much DC power it will produce under “standard Test Conditions (STC) These are very carefully controlled laboratory conditions, that rarely (if ever) will exist in the real world. All modules get slower (degrade) over time and the standard guarantee states that the module will perform at 90% after 10 years and 80% after 25 years.

Unfortunately, for the typical end user they do not have any means to test this promised degradation.

  • It is impossible to ask the sun to shine at standard test conditions.
  • The guarantee only promises a DC output, and end user solar monitoring is measured in AC power after the inverter has changed it to useful electricity.

Even if an end user decided to send their modules to a third party lab for testing and managed to prove their claim, they would only be compensated for the product cost, not the lost production and as we know, a single faulty module will lower the output of the complete system. This guarantee is hugely important for large industrial and utility scale projects, but from a residential or commercial end users perspective this guarantee provides very little value.

End user verdict: From a practical perspective completely useless for residential end users.

Solar Inverter Product Warranty

Again, this is a pretty standard product warranty that everyone is familiar with. The warranties on inverters have been increasing over the past number of years so that the industry standard has moved from 5 years to 8 years, with some brands now offering 10 or 12 years. If any component in a solar system is going to fail it is most likely the inverter and when the inverter fails every single one of the solar modules connected to it are taken out of the game.

Good service and a speedy resolution are critical. End Users will be requested to get in touch with their installer who can inspect the system and then, if necessary, make a claim on your behalf to the manufacturer. Many brands will offer compensation to the installer for their time and effort in replacing a faulty inverter, so hopefully this doesn’t cost you anything. Your installer should have faith and confidence in the inverter they are offering you, if they are not willing to provide you with a basic level of after sales service at no extra charge, then chances are they are selling you a dud or at least a brand that isn’t giving them the support that other companies can. Just like the solar module product warranty, this only covers the product costs (typically repair/replace) and not any power losses caused by failure.

End user verdict: Contract your installer to inspect and replace faulty inverters. A faulty inverter should be repaired or replaced very quickly leaving your system running smoothly at minimal cost to you. Definite advantage in longer warranty periods, but you are going to be better off with a reliable inverter with shorter warranty period than an often breaking inverter with a long warranty.

kWh output guarantee

As the industry matures, brands have appeared that offer total system solutions in an effort to reduce the complexity of purchasing solar and to provide guarantees that are meaningful to a typical residential end user. One of the ways they do this is by guaranteeing the total power your system should produce and promising to pay back any shortfall in cash at an agreed price/kWh.

The guaranteed amount is in AC power so you can easily compare what has been produced Vs guaranteed through your monitoring apps without incurring any additional costs. The guarantees only cover a % (~90%) of the expected output and the term will be over a 5 or 10 year period so intra-year variations in weather can be offset. This means that the earliest you can make a claim is probably 5 years after installation, but as the brand has a stake in your system performing to its peak, they may engage in some sort of pro-active monitoring which will pick up any product faults and make sure they get repaired quickly.

This is a customized guarantee that is specific to the details of your roof, location and components used, if your installer does not supply these accurately your guarantee will be void. Most kWh guarantees also include a number of exclusions relating to allowed shading and installation guidelines, so as in all matters, a good reliable installer is key.

End user verdict: Far superior to the module (DC) only performance guarantee. A measureable and meaningful promise structured specifically for small system owners. Make sure that your installer complies to the underlying conditions of the guarantee and provides accurate information to the solution brand.

Warranty insurance

If you have done your research you have most likely come across a statement along the lines of “a 25 year guarantee is nice, but it is worthless if the company is bankrupt”. This statement is equally valid for 5 or 10 year product warranties and kWh guarantees. Even the casual observer will be aware of the problems the solar industry has faced. Without going in to the reasons or the future outlook, the truth is the solar industry has seen a number of large, very high profile bankruptcies.

Warranty insurance can be considered a backstop if the original brand goes bankrupt, whereby the insurer will take their place and accept claims. This type of insurance has been subject to all types of bogus marketing claims, forcing some of the insurance companies to come and make statements of clarification to the public about what is covered.

Things to watch out for:

  • Does the insurance coverage need to be renewed every year? (Obviously self defeating if company is bankrupt and not around to renew). Insurance should cover full 25 year term.
  • What % the total value of modules produced by a factory are covered by the insurance limits?
  • Can you verify your modules are covered?

Interestingly, this type of insurance is only currently available for solar module warranties, but we expect to see more solar inverter brands starting to offer it as the number of high profile failures in this space grows in coming years.

End user verdict: If the product brand can supply this, then they are doing a lot of things right which is meaningful by itself. Given the limited usefulness of the product warranty that this insurance backs up, in reality, it is not so important whether your specific modules are covered or not.

PV system insurance

The golden goose for residential end users has to be a kWh guarantee that is backstopped by a reputable insurance company. Unfortunately, the industry is not quite at the level of maturity where this can be offered to residential and commercial end users, but it is available for large utility projects.

For now, the closest alternative is “PV System Insurance”. It acts a little bit like a specialized solar home and contents insurance. You are covered for any damage to equipment and importantly loss of production if something happens to your solar system from things like hail or fire. However, it does not insure you against performance losses caused by product defects or failure. “PV System Insurance” is typically only available if the product brands used have passed the insurers factory audits and financial inspections. The premiums and excesses of these policies are still focused more towards larger projects, but there are more and more suitable options for small residential systems.

End user verdict: Partial coverage for performance loss, but additional benefit provided may not be worth the cost. Similar to Warranty Insurance, simply being able to offer this to end customers means the brand has a strong focus on quality and bankability.

So... don't be fooled!

  • Understand what after sales support your installer will provide you and at what cost. They will be your go-between for any warranty or guarantee claim. A good reliable installer should mean good reliable products.
  • Product Warranties and Guarantees are inferior to full system warranties and kWh guarantees.
  • Companies that can offer third party insurance coverage have been through intensive quality and financial audits. Passing these tests is more meaningful to small system owners than what the coverage offers.
  • Product reliability and quality is more important than the length of the product warranty

Autarco offers you a 10 year module warranty, 25 year output guarantee, 10 year inverter warranty and a 5 year kWh outputguarantee, extendable to 10 years. Why settle for less?