What are the Warranties and Certifications I should look for in my rooftop PV system?

 

Highlights
  • Solar modules come with 5-year warranty against manufacturing defects as well as performance warranty of 90% of rated power output for 10 years and for 80% of rated power output up to 25 years
  • Other components (inverters, batteries, junction boxes, etc.) come with 1-year warranty extendable to 5 years
  • There are several IEC or IS standards that the various components of the solar system should comply with
  • Inverters are the only major component of a PV plant that are expected to be replaced within the lifetime of the plant
  • Batteries, if used, will also need to be replaced. They also require careful maintenance
  • Not all damage is covered by the manufacturer’s warranty e.g., shadow damage

 

A rooftop PV system is made up several components each of which have their own performance parameters. We provide a list of the prominent warranties and certifications for each component in the table below.

Warranties Certifications
Solar Panels
Modules are typically warranted against manufacturing defects for a period of 5 years. In addition, their power output is also warranted

  • 0-10 years for 90% of the rated output power
  • 10-25 years for 80% of the rated output power

This means that a 200 Wp panel will generate as much power as a 180 Wp panel in 10 years’ time (90%) and 160 Wp panel in 25 years’ time (80%).
Note: It is normal for solar panels to lose some of their generating power over time (about 0.5% a year). This is known as degradation.

The crystalline PV module (which are predominantly used in rooftops over thin-film modules) should be certified to comply with

  • IEC 61215/IS 14286 – Design qualification and type approval
  • IEC 61730 – Safety
  • IEC 61701/IS 61701 – Salt mist corrosion testing (for panels installed in coastal areas or in maritime applications)

Panels should also be supplied with the MNRE mandated RFID tag that allows the panels to identified and tracked to the manufacturer for verifying performance.

Inverters
Inverters are typically warranted for 1 year, with optional extension up to 5 years.
  • IEC 61683/IS 61683 – Efficiency
  • IEC 60068-2 (1, 2, 14, 30) – Environmental testing (Cold, Dry heat, Change of temperature, Damp heat cyclic)
Mounting structures
Mounting structures are typically warranted for 1 year, with optional extension up to 5 years.
Batteries
Batteries are typically warranted for 1 year, with optional extension up to 5 years. While battery certifications would depend on the application for which they are required, consumers can perform simple checks to verify if the battery is genuine

  • Capacity-weight – Capacity should correspond with the weight e.g., a 100 Ah battery should weigh about 32 Kgs.
  • Batch number – This should be embossed (and not provided through a sticker) on the body
Charge Controller/MPPT units
Charge controllers and MPPT units are typically warranted for 1 year, with optional extension up to 5 years.
  • IEC 60068-2 (1,2,14,30) – Environmental testing (Cold, Dry heat, Change of temperature, Damp heat cyclic)
Cables
Cables are typically warranted for 1 year, with optional extension up to 5 years.
  • IEC 60227/IS 694 – General test and measurement of PVC cables
  • IEC 60502/IS 1554 (Part I & II) – Working voltage up to and including  1100 V and UV resistance for outdoor installation of PVC cables
Junction Boxes/Enclosures for Inverters/Charge Controllers/Luminaries
Junction boxes and enclosures are typically warranted for 1 year, with optional extension up to 5 years.
  • IP 54 (of IEC 529) – Outdoor use
  • IP 21 (of IEC 529) – Indoor use

The certification for each component can be found on the datasheet for the component.

Expected lifetime of rooftop PV plant components

Rooftop PV plants have no moving parts and therefore don’t suffer from wear and tear, making them extremely reliable. The expected lifetime for the major components in your rooftop solar PV system is given below

  • PV modules – These should last 25 years, or even longer
  • Inverter – This is the only major component in the rooftop plant that will require replacement during the lifetime of the plant. Typical life is 5-10 years
  • Mounting structures – These should last the full 25 years of the plant’s lifetime
  • Batteries – Battery backups can last as long as 10 years with careful maintenance, but 3-5 years is a more typical lifespan
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Examples of component failure

While solar PV plants have no moving parts, the components of a plant can fail and require replacement due to several factors. A few examples are given here

  • Modules – Leakage of current into the frame of the module, resulting in 20-50% reduction in power output
  • Inverters – Capacitor failure due to ageing of electrolytic materials
  • Junction boxes – Improper fixing on panel causes the box to fall off the panel, creating a fire hazard

Failures not covered by warranty

Not all component failures are covered by warranties. These are typically due to poor design of the rooftop solar plant. Examples include

  • Modules – Shadows falling on the panels causes them to burn out (more details here)
  • Connectors – Overheating caused by poor fastening
  • Wiring – Squirrel or bird damage
Takeaways
  • Solar modules come with 5-year warranty against manufacturing defects as well as performance warranty of 90% of rated power output for 10 years and for 80% of rated power output up to 25 years
  • Other components (inverters, batteries, junction boxes, etc.) come with 1-year warranty extendable to 5 years
  • There are several IEC or IS standards that the various components of the solar system should comply with
  • Inverters are the only major component of a PV plant that are expected to be replaced within the lifetime of the plant
  • Batteries, if used, will also need to be replaced. They also require careful maintenance
  • Not all damage is covered by the manufacturer’s warranty e.g., shadow damage

 

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