Solar Feasibility Study by the DISCOM: What Is Checked and Why Applications Fail

The DISCOM feasibility study checks whether the grid can take your solar plant at your connection point. It looks at your sanctioned load or contract demand, whether dues are clear, how much capacity the supplying transformer can still host, whether the site has shadow-free space, and whether the application is complete. Rooftop plants up to 10 kW are exempt. Above that, the study is due within 15 days and silence counts as approval.

When is a feasibility study required, and how long may it take?

The Ministry of Power amended the Electricity (Rights of Consumers) Rules in February 2024. Its release of 23 February 2024 says rooftop systems up to 10 kW are exempt from the technical feasibility study. For systems above 10 kW the time allowed for the study fell from twenty days to fifteen, and if it is not completed in time the approval is deemed given. The same release says distribution strengthening needed for systems up to 5 kW is at the DISCOM's cost, and the DISCOM's time to commission rooftop systems fell from thirty days to fifteen. MSEDCL's order implementing the exemption quotes the new sub-rule (7A): applications up to 10 kW, complete in all respects, are deemed accepted without a study.

These are central rules. Each state commission's regulation fills in the detail, and the actual clock starts only when the application is complete. We have read the Ministry's release and DISCOM orders quoting the rule, not the gazette text itself, so confirm the wording and the day-count with your DISCOM. If your factory plant is above 500 kW, also read the net-metering limit in your state regulation; Haryana's 2021 rooftop regulation, for example, allows net metering up to 500 kW or the sanctioned load or contract demand, whichever is lower.

What does the DISCOM check?

Different DISCOMs publish different amounts of detail. The Haryana regulation's technical feasibility format and Maharashtra's MSEDCL operating procedure are two of the clearest, and between them they show the working checks.

How is transformer headroom worked out?

The two documents above use different formulas, and that matters. Under Haryana's rule the cap is a share of the rated capacity of the transformer, shared among everyone on it. Under the MSEDCL procedure the field officer's screen shows the transformer capacity, the rooftop capacity already sanctioned on it, and the headroom, which is 70% of the rating minus the sanctioned capacity. For illustration only: a 250 kVA transformer under a 50% cap hosts 125 kW of solar in total, and under a 70% rule 175 kW, before anyone's earlier sanction is subtracted. A plant that is 40 kW larger than the remaining headroom fails the check even if every other item is perfect.

Haryana's regulation also expects the DISCOM to publish available transformer capacity on its website and update it yearly, and it says refusal must come with a speaking order. For an HT consumer with its own transformer, the check moves upstream to the DISCOM's own transformer and feeder. The documents we read give a percentage cap for the power transformer but no feeder loading limit, so ask the DISCOM what it measures and whether a load flow was run. Our note on 11 kV connections goes through the HT side, and the article on transformer headroom and reverse power covers your own transformer.

Why do applications fail or stall?

• The transformer is full. Haryana's format has a box for "yes, but with reduced capacity", and the DISCOM must send a deficiency notice within 15 days; the applicant then has 15 days to resolve it or the application is cancelled. MSEDCL keeps the application on a waiting list in order of filing if the consumer chooses, and rejects it if not.
• Arrears. MSEDCL leaves applications pending while live arrears exist.
• Capacity does not fit the site. Not enough shadow-free area, or a capacity entered wrongly, is a listed ground for rejection; MSEDCL allows the applicant to reduce the capacity with a consent letter.
• The application is incomplete. The rule speaks of applications "complete in all respects", and the study clock runs from a complete file, so missing authorisation or ownership papers delay everything.
• The approval lapses. MSEDCL's sanction is valid for six months, and Haryana's letter of approval becomes void if the plant is not installed within 180 days unless an extension is allowed in writing.

Net-metering queues are also a regional issue; our piece on net-metering delays in Punjab and Haryana looks at the same problem.

How do you pre-check before you apply?

First, take your last twelve bills and fix the sanctioned load or contract demand and daytime consumption; the plant should sit inside both. Second, ask the DISCOM for the rating and code of the transformer that feeds you, and for the solar already sanctioned on it. Third, check dues. Fourth, commission a shading and roof-load check. Fifth, assemble the single-line diagram with meter, CT and protection details, inverter datasheets and the authorisation papers. Sixth, apply online if the DISCOM offers it and keep the acknowledgement, because the days run from it. After feasibility comes the agreement, installation, inspection and synchronisation; feasibility is not permission to connect.

How Secured Engineers helps

We design the plant in-house and file DISCOM net-metering, CEIG and Fire NOC applications in-house, so the feasibility application, the single-line diagram and the safety file say the same thing. MEPF and solar can be run under one contract. We work from our Noida (Delhi NCR) and Ludhiana offices across 535+ projects in 18+ states, and 89.77% of our clients are repeat clients. This article is a buyer's guide to the published rules and does not predict what your DISCOM will approve.

For a pre-check of your bill, transformer and roof before you apply, see our solar EPC service, message us on WhatsApp, call +91 70099 85817, or ask for a free proposal.