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

A factory in Bihar buys rooftop or ground-mount solar through its distribution company, NBPDCL in the north or SBPDCL in the south, under BERC's net and gross metering regulations. Plants above the net-metering ceiling go the captive or open-access route. The Electrical Inspectorate approves the installation. Turnkey cost on our published cost pages runs from about ₹28–32 lakh at 100 kW to ₹2.40–2.60 crore at 1 MW, excluding GST.

Who regulates and approves a factory solar plant in Bihar?

Four bodies matter, and a good EPC contractor files with all of them.

• The distribution company. Bihar has two, North Bihar Power Distribution Company (NBPDCL) and South Bihar Power Distribution Company (SBPDCL), under the Bihar State Power Holding Company. The SBPDCL net-metering notice is hosted on the holding company's site. Your bill names your company.
• BERC, the state regulator. Its rooftop regulations govern net and gross metering. BERC has issued a notice inviting comments on a second amendment to those regulations in 2026, and trade press reports a proposed ceiling of 500 kWp for net metering and a lower tariff for year-end surplus. Those figures are a draft until notified.
• BREDA, the state nodal agency. It runs the renewable energy programmes and publishes explanatory material on net and gross metering. The state's Energy Department lists the Bihar renewable energy policy of 2025.
• The Electrical Inspectorate. Its Energy Department page says it approves drawings for generating sets, including solar, and inspects them before commissioning. It also states that electrical installation work on a consumer's premises must be done by an electrical contractor licensed by the state.

The national frame sits above all four. The Electricity (Rights of Consumers) Rules, as amended in 2021, allow a state commission to permit net metering up to 500 kW or the sanctioned load, whichever is lower. They also set a fifteen-day period for the technical feasibility study of a rooftop system, with the proposal treated as feasible if the company does not respond (2024 amendment).

Which approval route fits which size?

The route follows the plant size against your sanctioned load or contract demand. The table shows the logic. It is a planning guide: confirm each row with your distribution company and BERC's current text.

These costs are the figures on our 100 kW, 500 kW and 1 MW pages. All are excluding GST and indicative. The band is the same ₹24,000–32,000 per kW published on our solar EPC page, with larger plants at the lower end. It excludes roof strengthening, HT-side works and statutory fees, which vary by site.

For a plant above the net-metering route, the captive test applies. The Electricity (Amendment) Rules, 2023 require the captive user to hold at least twenty-six percent of the plant's ownership, and fifty-one percent where an affiliate company owns it. Our open-access solar guide sets out the other conditions.

What does the Electrical Inspectorate expect?

The Bihar inspectorate's page lists service times for its online approvals. For new and renewable solar generation it shows an average of 26 days, with a range of 13 to 43 days, and for HT and EHT installations an average of 12 days. Read these as the portal's own statistics, not as a promise for your file. The submission itself should include an updated single-line diagram, earthing and site layouts, equipment list, test reports and the licensed contractor's details. A clean file is the quickest route to the permission for commissioning.

Where does industrial demand sit in Bihar?

The Bihar Industrial Area Development Authority's 2025 restructuring proposal counts 93 industrial areas, estates, growth centres and mega industrial parks under nine clusters. It proposes cluster offices at Patna, Hajipur, Muzaffarpur, Bihta, Begusarai, Gaya and Bhagalpur among others. For a solar buyer this means plots with a defined roof, a sanctioned load on record and an industrial-category connection. It does not tell you the DISCOM's feeder headroom at a given plot, which is a per-site question.

How should a Bihar factory read the payback?

Use the method on our cost pages and replace the inputs with your own. At ₹28,000 per kW, a plant generating about 120 units per kW per month produces 1,440 units per kW per year. Valued at an illustrative ₹9 per unit, with annual O&M at 1% of capex and exported units valued at zero, the simple payback is about 2.2 years if every unit is used on site, about 2.8 years at 80% self-use and about 3.7 years at 60%. These are arithmetic on stated assumptions, not a forecast.

Three inputs move the answer for a Bihar factory. The first is your actual tariff for the units solar displaces, which comes from your bill and not from our illustration. The second is generation: if the Bihar figure is 10% below 120 units, every payback above lengthens by about 11%. The third is self-use, which depends on your daytime load. A plant that exports a large share of its output under a net-billing or gross-metering arrangement is valued at the settlement rate the commission sets, and that rate is exactly what the amendment under consultation may change. Run your own numbers in the solar payback calculator.

What should a Bihar factory ask an EPC contractor?

• Which of NBPDCL and SBPDCL serves the plant, and whom the contractor has dealt with there.
• Whether the quote assumes the existing BERC text or the proposed amendment, and what happens to the design if the ceiling changes.
• Who files the Electrical Inspectorate submission, and whether HT works are in the price.
• The generation figure used. Our cost pages use about 120 units per kW per month for the north, and the East runs lower. Ask for the Bihar figure and its basis.
• The monitoring, O&M and warranty terms after commissioning.

The solar calculator gives an indicative sizing and payback by region in a minute, and the solar policy page lists the process by state.

How Secured Engineers helps

We are a pan-India solar and MEPF contractor, and we mobilise to Bihar sites from our offices in Noida (Delhi NCR) and Ludhiana. We have not published a Bihar project record, and we do not claim one here. Design is in-house; the Fire NOC, CEIG and DISCOM net-metering filings are made by our own team; MEPF and solar can sit under one contract. We have delivered 535+ projects across 18+ states, with 89.77% repeat clients. The industrial solar EPC page shows the full scope.

To test a plan against these rules, send us your last twelve electricity bills and the roof layout. See the solar EPC service, WhatsApp us, call +91 70099 85817, or ask for a free proposal.