Solar Inverter Suppliers Still Waiting for MNRE to Extend Deadline for BIS Certification

The lingering confusion around the policy and implementation of BIS certification for solar inverters has been a cause for concern in the industry for some time. As the date of implementation (January 1, 2019) draws near, the industry is still waiting for clarity on the subject from the government.

Mercom recently wrote about the struggles of inverter manufacturers in gaining clarity on the ambiguous BIS certification process. The unavailability of labs, lack of testing facilities and manpower, unreasonable costs of testing, absence of series guidelines, and confusion by MNRE notifications are just some of the issues that have made the compliance of the order Solar Photovoltaics Systems, Devices and Component Goods Order 2017 nearly impossible.

Taking this into consideration, the MNRE recently called for a meeting of solar inverter suppliers to discuss all the issues faced by them.

On the question of test lab availability for solar inverters, the MNRE was informed that the Underwriters Laboratories (UL) is not yet ready to conduct tests for BIS certification and will only be ready by March 2019 for both anti-islanding and safety standards.


The Central Power Research Institute (CPRI), the only government-authorized test lab for BIS certification for inverters, informed inverter suppliers that it is capable of testing up to 200 kW of inverters. With regards to the time needed to conduct the test, anti-islanding would take four days whereas safety-related tests will take 30 days.

However, inverter suppliers expressed their concerns in adhering to the deadline. An official from Delta, who attended the meeting said, “The January deadline was very unrealistic. So, one thing is clear, they will definitely extend the deadline. There are no labs available except CPRI and UL will only be available by next year by February or March.”

Commenting on the meeting, he added, “It was a success as everyone could voice their concerns. But it will take more meetings to come up with conclusions. Now, it’s up to the MNRE to come up with the framework for testing, for example – grouping of inverters as each supplier has its own family of inverters with different ranges.”

“It should first come up with the infrastructure for testing and create more labs as two labs will not be sufficient as one sample from one supplier would take one to one and half month. The next meeting may take place in January or February,” he elaborated.

MNRE has also asked the opinion of inverter suppliers regarding the series guidelines and inverter grouping. According to CRPI and UL, if the inverters have the same hardware and firmware, then those inverters can be clubbed in a single family.  In the family, the highest inverter rating can be tested for 100 percent and remaining inverters can be tested for 50 percent.

The MNRE representative suggested that a common group should be made based on the inverters rating like 1-5 kW, 6-15 kW, 16-30 kW. However, the inverter suppliers did not agree to the proposal as they have their own family grouping and this topic remained unresolved.

The inverter suppliers present at the meeting suggested the MNRE to consider the existing IEC test report and perform the testing for any one of the inverters from the family. However, the MNRE did not agree to the suggestion and is likely to come out with its own guidelines in consultation with the BIS. It has asked all inverter suppliers to share their inverter range with family or grouping details. The ministry will call for one more meeting to formulate the Inverter Series Guidelines.

Another inverter supplier present at the meeting said, “It was a good initiative from the MNRE and all the inverter suppliers came on the same platform and expressed their concerns to the government. Though the ministry did not confirm any extension of deadline or the next timeline, it has heard all the issues and it is most likely to extend the deadline.”

“The MNRE has to first come up with the guidelines for the categorization of inverters. Even if a lab has the facilities, it can’t test inverters in the absence of these guidelines. We expect that a reasonable extension of time will be provided until three or four labs become fully operational. It is not likely to have any testing facilities for central inverters in the next one year,” he further added.

Inverter suppliers also raised the issue of the high cost of testing. In reply, the MNRE assured them that it was aware of the issue and it would discuss with BIS and streamline pricing.

As no information on an extension of implementation of BIS registration was given in the meeting, an inverter supplier said, “A lot of import shipments are coming and will be held up in case the deadline is not extended. It is giving a lot of stress to the industry.”

Image credit: ABB