What kind of warranties or guarantees should I look for in a solar power system?
A solar power system should provide trouble-free operation as long as you’ve chosen the right equipment, and have selected an experienced installer. The instances of equipment failure are rare when the system is configured & installed properly as solar power systems have no moving parts and most components are rated to maintain long-term operation and performance. It is also important to understand that there are several components in a solar power system and typically these are not from the same brand or manufacturer, hence it is important to understand the different types of warranties and what they cover. Warranties can typically be classified as below:
Solar performance warranty
This is a power production warranty which guarantees that the solar panels will retain a certain percentage of their power production capacity over the first 25yrs. Most reputed manufacturers guarantee that the solar panel will not lose more than 10% of its rated output in the first 10yrs and not more than 80% in 25 yrs. Some manufacturers also provide a linear power warranty which plots a linear curve of the guaranteed power output over 25yrs. The production guarantee also offers a guarantee that the solar panels only lose a certain percentage of the production capacity each year (most good quality solar panels will not lose more than 0.7 percent per year).
Solar equipment warranty
This is a product or materials warranty offered by the manufacturer of each equipment and the warranty on key components is summarized as below:
Solar panel warranty
: Typically 10yrs.
This warranty guarantees that the solar panel is free from any manufacturing or durability issues and a ten year guarantee is typically provided as any defects if there would definitely show up within this period. The warranty covers all aspects that ensure the build quality of a solar panel – the frame that provides structural rigidity, the glass that protects the top side of the panel, the EVA which is the glue that binds together all components in the panel, the solar cells where sunlight is converted into electricity and the junction box & connectors which transfers energy from panel to the next.
Solar inverter warranty
The inverter is the heart of a solar system. An appropriately rated solar inverter under the right operating conditions will provide a useful life of 12 to 15 yrs, so, it is a fair assumption that it will have to be replaced once during the lifetime of the solar power system. The product or materials warranty for the different types of solar inverters is as below:
: Typically 5 – 10 yrs
: Typically 2 – 5 yrs
Solar Battery warranty
An appropriately rated battery bank under the right operating conditions will have a useful life of 7 to 10 yrs. Typical warranties for the different types of battery technologies is as below:
:Typically 3 to 5 yrs
:Typically 2 to 5 yrs
Lithium ion batteries
:While these are still very expensive in India they could come with warranties upto 10yrs
–Typically 1 to 2 years
This is offered by the system integrator or installer as a warranty for the workmanship. As described above, all key components of the solar power system are backed by robust warranties from the manufacturers, so the workmanship warranty is a sign that the installer is willing to stand behind the quality of the work covering system design, equipment selection and installation. The shorter duration of this warranty should not be of concern as any design or equipment selection related faults will be apparent almost immediately in the performance of your solar power system and will be rectified by the installer under the terms of the workmanship warranty. Thereafter, any deterioration in performance will primarily be due to equipment malfunction or failure which is covered by a robust product warranty. This should also assuage the concerns that homeowners often have with smaller solar companies going out of business or not being around to provide support through the lifetime of the solar power system.