BIS IS 16221 Certification - What It Means and Why It Matters
The Short Answer
Mandatory. Not optional.
BIS IS 16221 is the mandatory Indian standard for grid-connected solar inverters. If a solar inverter does not carry this certification, it is not legally permitted to be connected to the Indian grid. Zenergize inverters are certified. Many are not.
What BIS Actually Tests
Independent verification, not self-declaration
The Bureau of Indian Standards puts inverters through a rigorous set of tests before granting the IS 16221 licence. This includes safety under abnormal grid conditions, anti-islanding protection (so the inverter shuts off safely during a power cut), temperature performance, and electromagnetic compatibility. It is not a self-declaration - an independent lab verifies everything.
The PM Surya Ghar Connection
Subsidy eligibility requires this certification
The government's PM Surya Ghar subsidy Yojana scheme requires BIS IS 16221 certified inverters. If you want to claim the subsidy, your inverter must be certified. Zenergize inverters qualify.
Zenergize's Certification
Licence No. R-96004600
Our licence number is R-96004600, issued by BIS in January 2026 and valid through January 2028. It covers our full single phase range - GSTI-2K2-1P through GSTI-6K0-1P - manufactured at our Parwanoo facility.