Solar EPC for Factories in Assam: DISCOM Rules, Approvals and Cost

A factory in Assam can install 1 kWp to 1,000 kWp of rooftop solar at one location under the AERC regulations, limited to 100% of its connected load or contract demand, and is settled by net billing, not net metering. At the published C&I band of ₹24,000–32,000 per kW excluding GST, 100 kW is ₹24–32 lakh. APDCL connects the plant and the state Inspectorate of Electricity approves it.

What the rules allow a factory in Assam

The Assam Electricity Regulatory Commission (AERC) notified its Grid Interactive Solar PV Systems Regulations on 6 August 2019 and amended them on 18 June 2024. The Commission's August 2026 order quotes the 2024 amendment. Solar panel capacity at a consumer's premises must be between 1 kWp and 1,000 kWp. For both LT and HT consumers it is limited to 100% of the connected load or contract demand, wherever interconnection with the grid is technically feasible. The cumulative rooftop capacity on a distribution transformer is limited to 80% of that transformer's capacity.

The same order quotes the state solar policy of 2025: net metering for residential consumers with connected load up to 10 kW, and net billing (export-import metering) for all categories above that. A factory therefore falls under net billing. The state's Integrated Clean Energy Policy of February 2025 repeats the 1 kWp to 1,000 kWp window and says the maximum size under net metering or net billing is governed by the AERC regulations as amended. Because the rule speaks of panel capacity in kWp, size the DC array to 1,000 kWp or less, not the AC rating.

A change is pending at the AERC

In 2026 APDCL petitioned the AERC (Petition No. 09/2026) to amend the 2024 capacity clause and the net metering accounting clause. The Commission heard the matter on 28 July 2026. In its order of 5 August 2026 it said APDCL's financial analysis was incomplete, and that a proposal to restrict system capacity or stop payment for surplus energy needed a complete and verifiable study. Pending a final decision it directed APDCL to process all rooftop applications under the existing rules and not to hold applications back because the petition is pending. APDCL was asked to file a revised study by 26 August 2026. We could not find a final order on the AERC site in October 2026, so read the notices page before you sign a contract. Build your payback with a margin for a change in how exports are valued.

Who approves, inspects and energises

APDCL, the distribution company, takes the application, checks feasibility against the transformer and feeder, and installs the meter. The state Inspectorate of Electricity handles the safety side. Its application form says no electrical installation or apparatus above 650 volts may be energised without the Inspectorate's written approval, and cites Regulation 43 of the 2010 CEA safety regulations. The 2023 regulations replaced that text, so confirm the current numbering and the document checklist with the Inspectorate. The state's Energy Development Agency, AEDA, publishes information on rooftop programmes. Our pages on CEIG approval and CEIG consultancy explain the inspector's file.

What 100 kW, 500 kW and 1 MW cost

Secured Engineers publishes a C&I band of ₹24,000–32,000 per kW excluding GST on its solar EPC page, and its size pages publish their own figures. The table applies both to the three sizes asked about most. Generation uses the East and North East planning range of about 105 to 115 units per kW per month, lower than the 120 used for north India. All figures are indicative, not a quotation for an Assam site.

A 1 MW plant sits exactly on the 1,000 kWp ceiling, so a DC array larger than that would not fit the rooftop rule. Use the solar calculator for your own bill. Monsoon cloud cover and rain affect yield through the year, and dusty sites need a cleaning plan.

Where factory demand sits, and what the state policy adds

The Industries and Commerce Department lists industrial infrastructure by district. It includes the Industrial Growth Centre at Chaygaon-Patgaon-Jambari in Kamrup, and industrial estates at New Bongaigaon, Tinsukia and Cinnamora in Jorhat. Factories in these clusters are the natural rooftop customers, because they have large sheds and daytime load. Check whether the allotment terms of an industrial estate affect roof use.

The Integrated Clean Energy Policy of February 2025 adds incentives that you should check against your case. It provides 100% exemption from electricity duty for power consumed from RE plants from commissioning during the policy period. It says cross-subsidy and additional surcharge do not apply to consumption from plants that meet the captive criteria of the Electricity Rules, 2005, and exempts certain captive and third-party arrangements under open access for up to 20 years or project life. It sets a target of 1,000 MW of industrial and commercial rooftop within a 1.9 GW rooftop target. Ask APDCL whether the duty exemption applies to your rooftop plant, and read clause 5.8 against your structure. For captive and open access, see our open access solar page.

How Secured Engineers helps

Secured Engineers is an EPC contractor that designs solar plants in-house and files the CEIG and DISCOM net-metering applications in-house, with MEPF and solar under one contract if a site needs both. It has no project on record in Assam and mobilises from its offices in Noida (Delhi NCR) and Ludhiana. Across the company, 535+ projects in 18+ states and 89.77% repeat clients are on record.

If you are comparing solar EPC contractors for an Assam factory, ask each for the AERC and APDCL steps in their programme. Our solar EPC service page sets out our scope. Send your bills and roof details on WhatsApp, call +91 70099 85817, or ask for a free proposal.