Confusion Around BIS Certification for Solar Inverters

Inverter manufacturers, sharing the same fate as the module suppliers, are still struggling to gain some clarity on the government policies for BIS certification


The Indian solar market has expanded impressively over the past few years and as the market has grown the government has begun to pay attention to quality issues. The concern is valid as solar projects are expected to last 25 years it is important to make sure they are built using quality products including modules and inverters.

Realizing the issue, the Ministry of New and Renewable Energy (MNRE) recently issued guidelines for conducting tests on power inverters for use in photovoltaic (PV) power systems and utility-interconnected PV inverters.

The government has mandated that the tests must be conducted by labs for compulsory registration with the Bureau of Indian Standards (BIS) for the implementation of the order titled Solar Photovoltaics Systems, Devices and Component Goods Order 2017.

Since the notification was released in September 5, 2017, the deadline has been extended several times as the industry has been seeking more and more time for the compliance of the order. The latest deadline for the compliance of the order is January 1, 2019.

In the latest notification dated  October 12, 2018, MNRE stated:

“The date of self-certification relaxation stands extended to January 1, 2019 from September 20, 2018 for all items with date of implementation indicated against each product, with the standard IS 16221 (Part 1) listed against item at SI No. 4 in the principal order dated 5.09.2017 excluded from the order.”

The notification makes it clear that IS 16221 (Part 1) titled ‘Safety of Power Converters for use in Photovoltaic Power Systems Part 1- General Requirements’, is excluded from the BIS certification.  However, many inverter suppliers have been complaining that the Central Power Research Institute (CPRI), the only government authorized test lab for BIS certification for inverters, is not adhering to the notification strictly.

“While quality standards are essential considering solar projects are expected to be for around 25 years or more, it is also important to make sure that there are enough facilities that are equipped to handle testing and costs are not an added burden for smaller suppliers,” said Raj Prabhu, CEO of Mercom Capital Group. “The last thing you want to do is create additional bottlenecks for the industry that already has plenty of challenges to worry about.”

An inverter supplier not wanting to be named informed Mercom, “There is confusion between CPRI and MNRE notification. As per the recent MNRE notification, IS16221 Part 1 is excluded from the order. But as per the Lab, in IS16221 Part 2, there are a few tests which need to be done as per IS16221 Part 1 and there is no clarity about the testing. The cost of testing for part 1 was higher than the Part 2, but once Part 1 was excluded from the testing, they increased the cost of Part 2 saying we need the test results of Part 1 and therefore need to repeat the test. Because of this ambiguity, labs are charging exorbitant testing fee per model. It becomes highly difficult to justify the charges based on the sales volume for a particular model.”

Another inverter supplier echoed the sentiment saying, “There is no clarity regarding the policy. First, the MNRE rolled out compliance of three BIS standards in inverters, but in the latest notification they have reduced it to just two standards. Now, when we go to the CPRI, we get the quotation for all three standards. CPRI is not reducing the quotation to two standards. It continues to maintain that BIS for inverter comply with all the three standards.”

A senior official from another large inverter supplier also told Mercom, “We don’t have any window where we can get clear information about what can be done in the situation. For example, what are the regulations we need to follow? We don’t know who to approach for this.”

Lack of test labs and their testing capabilities are another area of concern. Some of the inverter suppliers have also raised the issue of high costs.

On the question of testing facilities, an inverter supplier opined, “At present, CPRI is the only testing center available to test inverters for BIS certification and even they are not properly equipped. They can only test up to 60 kVA of inverter rating. We have various inverter products with multiple ranges and there is a lack of clarity with regard to grouping of inverters for testing. For example, the hardware platform for inverters from 12.5 kV to 27.6 kV is the same. So, when we do the listing for IEC certification elsewhere, we do the grouping based on our declaration of platforms. Here, that clarity is missing. If they do not allow for the grouping, then the test charges for one model will come around ₹4,500,000 (~$63,752) with liaising and BIS fees. This is a huge cost. It would be better if the CPRI considers the groupings as per product IEC certification.”

“It is a time-consuming process. After waiting for ten days, we get the quotation, but if the quotation has ambiguity related to number of standards, it makes the whole process uncertain. The management will not take any decision for the short term. Even CPRI does not have the testing facilities for all three standards yet”, said a supplier.

He added, “We have informed about these issues to the concerned officials at the MNRE. They have asked us to go only for two standards now. However, he did not guarantee anything about the future. In case we go ahead with the latest notification for two standards and later MNRE says that all the three standards would comply, it will disturb the entire product costing. Another problem is the rate quoted by the CPRI is higher than any international IEC labs, for example TUV or UL labs. It is quoting around $1.2 million for 15 models.”

Another well-known inverter supplier commenting about the cost of testing said, “We spend millions of dollars on developing our systems and pay for test labs abroad. So, the cost is not a criterion because it is the part of the package. But the problem is the capability of the test labs. Somebody has simply imposed the rules, but we don’t know how to implement it.”

Lack of testing facilities in the country has made it impossible for inverters suppliers to get their products certified before deadline, which is January 1, 2019.  The lab at the CPRI for testing inverters is also new and doesn’t have enough qualified manpower at present.

An international inverter supplier commented on the situation “The standard lead time for testing IS16169 and IS16221 are approximately eight weeks as per the lab, and since many inverter vendors are approaching and submitting the samples, the lead time can increase even up to 12 -16 weeks.”

He added, “MNRE should call a meeting of all stakeholders and the first focus should be on the availability of labs and the time taken to conduct these tests. Fixing the deadline should be the last thing.”

Another executive working with an inverter supplier had similar views. “In India, we have 10-12 inverter suppliers, and each supplier has minimum 15 models. If you take 15-20 days needed to test and certify a single inverter supplier, it would take the next 4-5 months,” he said.

“We have always suggested that the MNRE should extend the deadline before it expires. But it always extends it after the deadline expires. This creates a problem for us because compliance of an order is in force when they are released, and we have to comply with it even if our consignment is in transit or at port.”

“We believe that there will be an extension of the deadline for at least two months. They may also accept self-certification accompanied with the IEC certificate and test reports,” he added.

On question of following the BIS norms, an inverter supplier said “We are willing to do that. But how? We don’t even have the test labs. We don’t have the equipment for test labs. So, when someone is asking us for the BIS certification, we say – let us know where we can get them. We are not the only one who is facing this problem, it is across the industry.”

The view of most of the inverter suppliers we spoke with seems to be that the January 1, 2019 deadline is unrealistic and needs to be postponed. When selecting the next date, the authorities need to understand the availability of labs, manpower and capabilities before picking a new deadline.

“If the date of implementation is not extended, everybody will be in a mess,” a supplier asked.

Mercom India also reached out to CPRI for its comments on the current situation.

On the question of capabilities and readiness of the lab, a CPRI official involved with the BIS certification said, “We are ready with the testing and can test up to 60 kW of inverters. We have testing facilities up to 200 kW and 500 kW, but it is not ready and may take another six months.”

Addressing the cost for testing, he added, “the cost is as per the testing requirements. If some tests are not applicable and not are being conducted, we will refund the amount.”

On the question of confusion related to exclusion of IS 16221 (Part 1) from the certification, he clarified, “The confusion is because of the wording of the sentence. There is difference between Part 1 and Part 2 standards. Part 2 talks about the extra tests apart from the Part 1 standards, but the part 2 also says that tests which are repeating or referring to the part 1 in part 2 standard will be excluded, in case the supplier has the certificate for part 1 tests.”

The CPRI official also made it clear that it is difficult to predict the time taken for testing. He said, “it depends on the technician available from the inverter suppliers’ side. A technician is a ‘product expert’ and we are ‘standard expert’ and need to discuss and work together. A test mentions many technical terms which we as ‘standard expert’ may not be aware of. After we see the inverter and talk to the technician, the testing time can be predicted.”

Responding to the question of grouping of inverters for testing he added – “MNRE is in the process of making series guidelines and it will be out soon.”

This is not the first time that issues have cropped up regarding BIS certification.

Mercom recently wrote about the lingering confusion in terms of the specific guidelines issued by the MNRE on BIS certification of solar modules. Like inverters, the certification of modules has also been a nagging pain point for the solar industry in India. It is common knowledge in the industry that the manufacturers have to lone up to get their modules certified. There are reportedly just 10-12 domestic and international players who have received the BIS certification.

“These issues keep cropping up as policies are made and orders issued without understanding the capabilities available to execute them on a set deadline,” added Prabhu.