An EPC running rooftop volume under PM Surya Ghar has one inverter brand written into every open quotation. That brand is a line in the bill of quantities (BOQ). It is also a make and model on the DISCOM net-metering application, and a serial number on the subsidy claim. On 17 August 2026 the Ministry of New and Renewable Energy (MNRE) issued an Office Memorandum. It can remove some of those brands from the scheme in 30 days. The memorandum is addressed to inverter manufacturers. The commercial loss, if a manufacturer does not respond, lands on the installer holding the quotation.
Direct answer. MNRE Office Memorandum F. No. 318/87/2024-Grid Connected Rooftop-Part (1) is dated 17 August 2026. It requires that all applications, monitoring and control servers, and real-time data for rooftop solar systems under the scheme reside exclusively within India. Every inverter OEM must send a written confirmation in the Annexure-I format to REC, copied to MNRE, within 30 days of issuance. An OEM that misses that window “shall not be allowed to install their systems on Rooftop Solar installations under the scheme”. OEMs must also fold datalogger warranty into inverter warranty and push daily cumulative generation data to the National Portal through a uniform API.
TL;DR
- Inverter data for PM Surya Ghar systems must sit on servers inside India. Cloud hosting outside the country is now non-compliant for this scheme.
- Counting 30 days from the 17 August 2026 issuance date puts the OEM confirmation deadline at 16 September 2026. Confirm the operative date with REC before you plan around it.
- The penalty is exclusion from the scheme, applied to the OEM. The disruption is felt by the EPC whose quoted BOQ names that OEM.
- This is the fifth MNRE instrument on inverter data since June 2024, not a standalone rule. The earlier four set the communication architecture this one enforces.
- Datalogger warranty must now sit inside the inverter warranty, which changes what your supplier is contractually on the hook for.
- The reporting burden is one daily cumulative generation figure per inverter serial number, not continuous live telemetry.
- Ask every inverter supplier for a copy of their filed Annexure-I before you release the next purchase order.
This guide is for Rohan, the India-based EPC owner or PM Surya Ghar registered vendor running rooftop volume across one or more DISCOM territories. He does not need the memorandum summarized back to him. He needs to know which of his open projects carry risk, and what to ask his inverter supplier this week. He also needs to know what happens to a net-metering file if the inverter make changes after submission.
What the 17 August 2026 memorandum actually requires
The memorandum runs to six directives under paragraph 5. Each one binds the inverter OEM, and each one has a consequence that reaches the installer.
| Directive | What it requires | Who it binds | What it means downstream |
|---|---|---|---|
| Data residency | Applications, monitoring and control servers, and real-time data, including anything on cloud platforms, must be encrypted and reside exclusively within India | Inverter OEM | An OEM running an offshore monitoring cloud must migrate or exit the scheme |
| Datalogger warranty | Datalogger warranty must be included inside the inverter warranty | Inverter OEM | Your supply contract should reflect one warranty, not two |
| Written confirmation | Confirmation to REC, copied to MNRE, in the Annexure-I format, within 30 days of issuance | Inverter OEM | You can ask to see the filed copy |
| Non-compliance | An OEM that does not file “shall not be allowed to install their systems” under the scheme | Inverter OEM | Your quoted BOQ brand can become uninstallable under PMSG |
| Point of contact | An official PoC must be intimated to MNRE alongside the confirmation | Inverter OEM | A named escalation route exists for data issues |
| Daily generation data | Daily cumulative generation, mapped to inverter serial number, pushed to the National Portal through a uniform API | Inverter OEM | Serial number capture at commissioning becomes a hard requirement |
Annexure-I is prescriptive. It asks the OEM to name the brand and BIS registration number, the GSTIN or CIN, and every inverter and datalogger model supplied under the scheme. It also asks for the specific data centre name and city where the data resides, and carries a false-declaration clause with the same exclusion penalty.
That level of specificity matters for a practical reason. An OEM cannot satisfy Annexure-I with a general assurance. It has to name a data centre inside India. That is a document you can ask to see.
The five-instrument inverter compliance chain
Most installers first encountered this rule when the August memorandum circulated. Reading it alone gives a misleading picture, because it is an enforcement instrument layered on top of four earlier ones. The memorandum itself lists the earlier documents in paragraph 4.
| Date | Instrument | What it established |
|---|---|---|
| 07.06.2024 | CFA Guidelines for PMSG: MBY, Clause 2.7(xiv) and Clause 8(a)(ix) of Annexure-3 | Inverters must have an inbuilt facility to communicate system data via SIM or dongle, and generation data goes to the National Portal |
| 21.07.2025 | OM on compliance requirements for inverters and communication devices | Machine-to-Machine (M2M) SIM communication is mandatory for all dongles and dataloggers under the scheme |
| 24.12.2025 | Guidelines on inverter communication devices, dongles, dataloggers and RMS | Vendor-neutral, secure, interoperable architecture for talking to the centralised IoT SCADA platform |
| 27.03.2026 | Testing guidelines for inverter RMS and dataloggers | Structured testing and validation, with an interim platform for OEMs to validate devices before full deployment |
| 17.08.2026 | This memorandum | Data residency inside India, 30-day attestation to REC, exclusion for non-filers, daily API push |
Read as a chain, the intent is clear. The first instrument said the data must exist. The second said how it travels. The third said what the architecture looks like. The fourth said how it gets tested. The fifth says where it lives, and attaches a penalty with a date on it.
Two operational conclusions follow. First, an OEM that has been quietly non-compliant since 2024 cannot fix its position with a letter. It has to have already done the engineering. Second, an OEM that participated in the 2025 and 2026 testing cycles is probably in a position to file quickly. The filing deadline separates those two groups in public, which is exactly why it is useful to you.
Why MNRE is enforcing data residency now
The memorandum states the reasoning directly in paragraph 3. Data communication from rooftop plants at large scale creates integration and cybersecurity exposure. Inverter communication modules that transmit to servers outside India risk “exposing generation data and unauthorize control of devices”.
The second half of that sentence is the operative concern. A monitoring channel that can read an inverter can usually also write to it. Firmware updates, remote shutdown, and setpoint changes travel the same path as telemetry. Concerns about undocumented communication hardware inside imported inverters have circulated internationally. MNRE’s framing of unauthorized device control tracks that worry rather than a pure privacy argument.
The scale explains the urgency. PM Surya Ghar crossed 50.06 lakh household installations and 14.8 GW of commissioned rooftop capacity as of early August 2026, according to pv magazine India, reporting MNRE figures. July 2026 alone added around 5.06 lakh households, roughly 16,300 installations a day. The scheme carries an outlay of ₹75,021 crore and a stated target of one crore households.
A distributed fleet at that size, addressable from outside the country, is a grid-security question rather than a scheme-administration question. That reframing is what gave MNRE the room to attach an exclusion penalty to a paperwork deadline.
The architecture your supplier has to already support
The December 2025 and March 2026 instruments define the technical layer. You do not need to implement any of it. You should recognize it when a supplier claims compliance, because it is specific enough to be checkable.
Communication between the remote monitoring system and the platform runs on MQTT. Traffic is encrypted using AES-256 over TLS or SSL, according to reporting on the December 2025 guidelines. The testing framework adds IMEI-based device identification and TLS certificate authentication. It covers three communication modes: periodic push, push-on-event for alarms and faults, and on-demand read and write for remote diagnostics. Device-side connectivity is specified as RS485 and Modbus to the inverter, with LAN, Wi-Fi or cellular 4G and 5G for the uplink. Onboard storage sits in a 16 MB to 256 MB range, according to Energetica India’s coverage of the March 2026 testing guidelines.
A supplier that can answer questions at that level of detail has done the work. A supplier that answers “yes, our system is MNRE compliant” and stops has told you nothing. The distinction is worth two minutes on a call.
The myth: this is a live telemetry mandate like PM-KUSUM
A common reaction inside EPC teams is that every rooftop system now needs continuous streaming, and that connectivity in weak-signal districts makes the scheme unworkable. That overstates the requirement.
Paragraph 5(vi) of the memorandum is narrow. It asks for “cumulative energy generation data for a day, mapped against the Inverter Serial Number”, pushed to the National Portal through a uniform API. It explicitly limits that API to “the minimum required parameters including daily generation data”. One manufacturer, quoted in trade coverage of the integration testing, described the burden as one daily submission with historical aggregates. That is a direct contrast with PM-KUSUM’s ten-minute live data over MQTT.
The memorandum also frames the arrangement as transitional. It continues only until central servers are developed at state and DISCOM level. At that point the DISCOMs capture generation data themselves and pass it to the National Portal.
There is a real tradeoff underneath the reassurance. A daily aggregate is cheap to transmit but useless for diagnosing a string fault on the day it happens. An EPC selling an operations and maintenance contract on the promise of live performance visibility is selling something the scheme’s minimum does not deliver. That capability comes from the OEM’s own monitoring product, which is now the thing that must be hosted in India.
Where the risk actually sits for an EPC
The memorandum’s penalty clause binds the OEM. Read the sentence again with an installer’s eye: such an OEM “shall not be allowed to install their systems on Rooftop Solar installations under the scheme”. Nobody fines the EPC. The EPC simply discovers that a brand it has already quoted, and possibly already purchased, cannot be commissioned under PM Surya Ghar.
Work through what that does to a live project file.
A rooftop net-metering application names the inverter make, model and capacity. The single-line diagram (SLD) drawn for the DISCOM reflects that inverter’s string configuration, protection ratings and AC output. Change the inverter after submission and the drawing set no longer matches the installed plant. Depending on the DISCOM, that is either a revision or a resubmission, and resubmission means re-entering the approval queue you already waited in. Our state-by-state DISCOM net-metering process guide covers how differently those queues behave across territories.
The subsidy claim adds a second dependency. Payment under the scheme runs against a commissioned, inspected system with documented equipment. An inverter swap between sanction and commissioning is exactly the kind of mismatch that stalls a Direct Benefit Transfer file.
Then there is inventory. Consider an EPC that bought a quarter of inverter stock ahead of a price movement, from a brand that later fails to file. That equipment is still good hardware, and still saleable outside the scheme. It is not usable on the PM Surya Ghar pipeline it was bought for.
None of these are hypothetical failure modes invented for an article. They are the same three exposures the ALMM list and its effect on solar BOQs has already created for module procurement. The pattern repeats because the enforcement design is the same. A central list, a dated cutoff, and a penalty applied to the manufacturer rather than the installer.
The Annexure-I ask: what to send your inverter supplier this week
The memorandum gives you an unusually clean lever. Every OEM has to produce a specific document, in a specific format, by a specific date. You are entitled to ask whether it exists.
Send this to every inverter supplier on your approved list, before releasing your next purchase order.
- Have you filed your Annexure-I confirmation with REC, copied to MNRE, under OM F. No. 318/87/2024-Grid Connected Rooftop-Part (1)? Ask for the filing date and a copy of the submitted letter. It is on their letterhead and it is not confidential to you as a channel partner.
- Which data centre and city hosts the monitoring data for our installations? Annexure-I item B.6 requires them to name it. A supplier that cannot answer has either not filed or has filed something it cannot support.
- Which specific makes and models of inverter and datalogger are covered? Annexure-I item B.5 is model-specific. A brand-level assurance does not cover a model that is not listed.
- Is the datalogger warranty now inside the inverter warranty, and for how long? Paragraph 5(ii) requires it. Get the revised warranty text, not a verbal yes.
- Who is your notified Point of Contact? Paragraph 5(v) requires a named PoC with an official email. That is your escalation route when a serial number fails to appear on the National Portal.
- How will inverter serial numbers be mapped for the daily API push? Ask what they need from you at commissioning. Serial number capture is now a data obligation, not a warranty formality.
Log the answers with a date against each supplier. If a supplier goes quiet through the deadline window, that silence is your answer. Better to have it in September than to find out on a commissioning visit in November.
Watch out. The 30-day count from a 17 August 2026 issuance date gives 16 September 2026, and that date is being reported across trade press. It is still arithmetic on a memorandum, not a date MNRE printed. Before making a procurement decision that depends on it, confirm the operative deadline and current filing status with REC, the National Programme Implementation Agency. Do not treat this article, or any trade report, as the authority on a live compliance date.
The cost question the memorandum does not answer
Data residency itself is an OEM cost. The connectivity underneath it is not, and the memorandum is silent on who pays.
MNRE floated the M2M SIM requirement in draft during August 2025. Freyr Energy’s Saurabh Marda then estimated the added cost at ₹18,000 per system over ten years, according to pv magazine. He said it was unclear who would bear it. In the same coverage he argued that undefined compliance scope makes financial planning uncertain for developers and consumers alike. He warned that smaller installers and price-sensitive segments carry disproportionate exposure. Exolar Energy’s Arvind Kumar supported the security objective while noting Indian manufacturers still depend on imported inverter control cards.
Treat that ₹18,000 figure as what it is. It is a 2025 draft-stage estimate from one installer, on a requirement whose commercial terms have moved since. It is useful as an order of magnitude, not as a line item. On a residential system, a cost of that size spread over ten years is not trivial relative to the subsidy. That is why the question of who absorbs it has stayed open for a year.
The practical position for an EPC is to get the connectivity cost written into the supply contract explicitly, on either side of the line. The alternative is discovering it at year three, when a SIM needs renewal and nobody agreed who owns it.
What this changes in your documentation set
Two things move, and both sit in the engineering file rather than the sales file.
The first is inverter make and model discipline. Once an inverter brand’s scheme eligibility can change on a filing date, “or equivalent” in a BOQ becomes a liability instead of flexibility. Specify the model, record why it was chosen, and date the compliance check that supported it.
The second is serial number capture at commissioning. The daily API push is mapped against inverter serial number. A commissioning process that photographs the nameplate but never transcribes the serial creates a reconciliation problem later. A system’s generation does not appear on the National Portal, and nobody can say which inverter it should have come from.
Both of these land on the same document set as the DISCOM submission. The electrical and CEIG drawing package carries the inverter schedule, protection ratings and SLD that a net-metering file is assessed on. It is the artifact that has to be reissued if an inverter changes late. For EPCs running volume across multiple DISCOM formats, keeping that package current against both the format and a moving equipment-eligibility position is a real operating cost. That is the argument for a rooftop detailed engineering design bench that already tracks both.
A pre-deadline checklist for EPC operations
Run this once now, and again after the filing window closes.
- List every inverter brand and model in your open quotations and unbilled pipeline. This is the exposed set. Nothing else matters until you know its size.
- Send the six Annexure-I questions above to each of those suppliers, with a reply-by date ahead of the deadline, and log the responses.
- Separate the pipeline into commissioned, sanctioned-but-not-commissioned, and quoted-only. Sanctioned but not commissioned is the highest-risk band, because the DISCOM file already names the inverter.
- Identify at least one alternative model per capacity band from a supplier that has confirmed filing. A substitute you have already technically evaluated is worth more in October than a search started in October.
- Check your current inverter inventory against the same list, and stop further stocking of any brand that has not confirmed until it does.
- Add the compliance check to your quotation template. The inverter named in a new quote is then verified on the day the quote goes out, with the date recorded.
- Update your commissioning checklist to capture inverter serial numbers into the project record, not only onto the nameplate photograph.
- Confirm the filing position and deadline with REC directly rather than relying on trade reporting, including this article.
Steps 1 and 3 take an afternoon with your quotation register. They are also the two that determine whether the rest of the list is urgent or routine for your business specifically.
What most EPCs will get wrong here
The predictable mistake is treating this as an OEM story and waiting to see what happens. That is understandable, because the memorandum is not addressed to installers and imposes no filing duty on them. It is still the wrong read, because the exposure is asymmetric. An OEM that files loses nothing. An EPC that assumed its supplier would file, and was wrong, loses the commissioning window on every project carrying that brand.
The second mistake is over-correcting into a rushed brand switch before the deadline. A supplier that has been through the 2025 and 2026 testing cycles is likely to file. Switching away from a technically suitable inverter on speculation costs real money in re-engineering and re-approval. The middle path is the one the memorandum makes available: ask for the document, and let the answer decide.
A third, quieter mistake is assuming this closes the subject. The compliance chain has produced five instruments in twenty-six months. The memorandum itself signals more movement, describing the daily API as an interim arrangement pending state and DISCOM level servers. The rule you verify in September is the rule as it stands in September. Our guide to DISCOM net-metering compliance in 2026 makes the same argument about state-level rules, for the same reason.
Conclusion
MNRE’s 17 August 2026 memorandum is a short document with a sharp edge. It requires rooftop solar inverter data to live on Indian servers. It gives every inverter OEM 30 days to confirm that in a prescribed format, and bars non-filers from installing under PM Surya Ghar.
- Your exposure is the set of inverter brands sitting in quoted and sanctioned projects that are not yet commissioned. Size that set first.
- Ask each supplier for its filed Annexure-I, the named Indian data centre, and the covered model list. Log the answers with dates.
- Do not switch brands on speculation, and do not assume silence means compliance. The filing deadline resolves the question for you.
- Verify the operative deadline and filing status with REC. The date circulating in trade press is arithmetic on the memorandum, not a separately published cutoff.
Maybe an inverter change forces a redraw on live DISCOM files. Maybe you want your rooftop drawing set reviewed against a substitute inverter before you commit to it. Either way, contact our engineering team for a project-specific review. You can also review a sample DISCOM-ready drawing package to see how the inverter schedule and SLD are structured in a submission-ready set.
FAQ
What is the deadline for inverter OEMs to confirm compliance?
The memorandum requires written confirmation within 30 days from the date of issuance, which was 17 August 2026. That gives 16 September 2026, a date now widely reported in trade press. Because it is a calculated date rather than one MNRE printed separately, confirm it with REC before acting on it commercially.
Does this rule apply to inverters outside PM Surya Ghar?
The memorandum is written for rooftop solar systems installed under PM Surya Ghar: Muft Bijli Yojana, and the exclusion penalty is specific to that scheme. Separate requirements apply elsewhere, including BIS registration and, for modules, ALMM. Do not assume a compliance position in one program carries to another.
What happens to my project if my inverter brand does not file?
Nothing happens to you directly, because the penalty binds the OEM. In practice the brand becomes uninstallable under the scheme. Any project of yours that quoted or specified it needs a substitute inverter. Any DISCOM file that already names it may need a revised drawing set and resubmission. Confirm the position with your DISCOM before assuming a revision is enough.
Do I need to install any new monitoring hardware myself?
No. The obligations in this memorandum sit with the inverter OEM, covering server location, warranty structure, attestation and the API push. Your operational change is procurement verification and capturing inverter serial numbers reliably at commissioning.
Is continuous live data now required from every rooftop system?
No. The memorandum asks for cumulative energy generation for a day, mapped to the inverter serial number. It states the API is limited to the minimum required parameters. It is a daily aggregate rather than continuous streaming, and MNRE describes the arrangement as running only until state and DISCOM servers take over the capture.
What is M2M SIM and why does it matter here?
Machine-to-Machine (M2M) SIM is a cellular connectivity type intended for devices rather than people. MNRE’s Office Memorandum of 21 July 2025 mandated it for all inverter communication devices, dongles and dataloggers under the scheme. It matters because it is the transport layer underneath the data-residency requirement, and because its recurring cost has never been formally assigned to a party.
Who pays for the M2M SIM connectivity over the system’s life?
The memorandum does not say. At draft stage in August 2025, Freyr Energy’s Saurabh Marda estimated ₹18,000 per system over ten years and flagged the ambiguity publicly, according to pv magazine. Treat that as an order of magnitude from 2025, and settle the question explicitly in your supply contract rather than leaving it open.
How does this relate to ALMM and BIS requirements for inverters?
They are separate regimes with separate triggers. ALMM governs eligible models and manufacturers, BIS registration governs product certification, and this memorandum governs where inverter data is stored and how generation is reported. A model can satisfy one and fail another. Our BIS solar inverter certification guide covers the certification track in detail.
Where can I read the original memorandum?
It is MNRE Office Memorandum F. No. 318/87/2024-Grid Connected Rooftop-Part (1), dated 17 August 2026, issued by the Rooftop Solar Division and signed by H C Borah, Scientist-E. Trade publications have reproduced the text, and MNRE publishes notices and memoranda on mnre.gov.in. Read the original before relying on any summary, including this one.