Warranty basics
Introduction
This section is only intended to serve as a brief guide to trigger the reader into exploring the potentially complex topic further. It is important to note product warranties are offered by the manufacturers who seldomly deal directly with the customers. The resellers are the facilitators between the manufacturer/distributor and customer in the event of a claim arising.
However, the seller has a legal responsibility under e.g. the UK Consumer Rights Act. 2015 and irrespective of the warranty offered, to fulfill with regards to refunds, repairs and goods sold being fit for purpose. This is not related to the manufacturer’s warranty and should not be confused with it.
Solar panel warranties
Consumers are often “sold” on warranties, but my advice is, make sure you have read and understand the fine print and the realities of warranties. Solar panel warranties generally consist of a hardware and a guaranteed linear output component:
Hardware warranty
10 Year warranties or more are not uncommon for domestic solar panels and covers the hardware such as the frame, electrical components, cells, glass in the event of any manufacturing defects arising within the warranty period. Warranties can vary widely between products and manufacturers and it is best to obtain the details of any warranties prior to making a purchase. Were the panel to have a hardware failure after this warranty expired, you have guessed it, that 25 year linear output warranty is quite obviously very much gone with it.
Linear output warranty
The linear output warranty is too often what consumers focus on and ranges from as little as 2 years to as much as 40 years today thank to data from long term field studies and large installations in use over 20 years.
This warranty will guarantee an estimated output after taking into account the degradation component of the cells over the period the panels were in use. This is of course based on controlled accelerated lab simulations of the performance and degradation characteristics of the cells and may read “1st year power degradation no more than 2% Subsequent annual power degradation no more than 0.55%”
Interestingly, long term cell degradation was not nearly as bad as initially estimated and warranties of up to 40 years are now on offer. This for me remains more symbolical of the confidence a manufacturer has in the quality of their product and also their greater understanding based on the outcomes of actual real world long term cell performance data.
The odd lifetime warranty
Although not not common, you may also come across a lifetime warranty which refers to the "lifetime" of the product. It is only valid for the lifetime of the product, so if the manufacturer stops producing the product after a year or two, the warranty expires. Wishing you had read those actual terms before your purchase and not followed the popularity vote on social media?
Warranty claims reality
The reality of solar panel warranties are that products change fast and you will unlikely find an equivalent replacement out there after a year or two, whether it be in output or physical dimensions. Furthermore, the cost of scaffolding, fault diagnoses, labour etc. may far outweigh the benefit of exercising the warranty, as these will quite often not be covered and not even to mention the challenge of demonstrating that you have a valid claim.
Regardless, were the warranty conditions all met and you indeed have a valid claim, it is more than likely that you will be financially compensated. This will take into account the time the product was in use, depreciation and current market value of equivalent products, which may be a lot less than what you have paid for it. Maybe this is something to think about before you get sold on warranties?
Storage (battery) warranties
It is not uncommon to find your storage system comes with e.g. a 10 year or 6000 cycles warranty at 80% DOD that guarantee 60-80% of the original capacity of the battery will still be usable after this time. Some offer shorter warranties and you explicitly have to register the product to obtain a “full warranty.” Also make sure of the terms of e.g. the inverter warranty that may be integrated in an AC coupled storage solution. Does the warranty apply to the performance of the cells only or also to the rest of the electronic components?
While it is not widespread yet, some manufacturers will expect as a warranty condition, for the product to be connected to their cloud so that they can have an overview or log of the product’s use over it’s lifetime and ensure it was used in line with the conditions as set out in the warranty conditions e.g. maximum DOD of 80% and not exceeding the nominal discharge rates frequently. Be assured it will not make for an easy claim as manufacturers and resellers will require “proof” to ensure all the warranty conditions were met. Fortunately modern storage systems have BMS (battery management systems) that will contain the logs and greatly help with your claim or by the same token can provide evidence of inappropriate use and invalidate claims.
Now, back to the real world
With still very little data and real world long term performance information of storage systems, much the same problems can be anticipated as with solar panels warranties such as backward compatibility of replacements or availability of components for repairs which may also be an issue etc.
Personally I am confident that when installed properly, in the right location and as per the manufacturer’s instructions, with proper use we will see storage systems serve households trouble free well beyond their warranty years.
Making a claim
The first port of call to make a claim for a faulty or malfunctioning product is always the seller. In the UK, the transaction will fall under the Consumer Rights Act 2015 making the seller legally liable to offer either a refund, repair or replace the product and even pay for the return shipping. This should not be confused with the manufacturer’s warranty/guarantee.
Note - Always first check your exact entitlements as there are time limits that apply to transactions. Of course, if the product was damaged as a result of improper use or installation (DIY’ers beware), you won’t have much of a foot to stand on.
Resellers will typically claim a replacement or repair costs from the manufacturer or their distributors through a RMA process under the warranty, depending on the arrangement they have in place. Whether they will/can supply a replacement from their stock will depend on various factors.
Note - Manufacturers as a rule do not directly handle warranty claims from the public.
It is important to note that in order to validate your claim, you may be expected to prove the product was installed by qualified installers and used in accordance with the conditions as set out in the installation and warranty documents from the manufacturer. This may influence your purchasing decision.