What a 750 kW Solar Plant Costs and Needs: Roof, Connection and Approvals

A 750 kW rooftop solar plant for a factory indicatively costs about ₹1.80 to ₹1.95 crore, excluding GST, at ₹24,000 to ₹26,000 per kW. It needs about 75,000 sq.ft of shadow-free roof, generates about 90,000 units a month in north India, usually connects on the HT side, and its economics depend on the state's net-metering ceiling and banking rules.

What does 750 kW cost, and how does it scale?

Our published benchmark for turnkey C&I rooftop solar is ₹24,000 to ₹32,000 per kW, excluding GST, falling as plants grow. We publish pages for 100 kW, 250 kW, 500 kW and 1 MW, but not 750 kW, so the figure here is scaled between the 500 kW and 1 MW pages and is indicative only.

The scope behind the band is a rooftop plant with modules, inverters, mounting structure, DC and AC cabling, earthing and lightning protection, protection and metering, installation, testing and commissioning, and the DISCOM liaison. It excludes HT-side works (a transformer or bay addition where the site needs one), roof strengthening, batteries, land for a ground-mounted alternative and statutory fees. At 750 kW, HT works and metering scope are the swing items. A bay that already exists in your substation keeps you inside the band; a new bay, cable run or transformer changes the number, and it is priced from the single-line diagram rather than per kW. Check the price basis in any quotation, because a quote that leaves out HT works will look cheaper and then grow.

Run your own bill through the solar calculator and then the solar payback calculator, which shows payback as scenarios by how much of the output you use on site. The smaller sizes are covered on our 100 kW and 250 kW pages.

How much roof does it need, and how much will it generate?

Plan on roughly 100 sq.ft of shadow-free roof per kW, so about 75,000 sq.ft for 750 kW. On paper that is easy; in practice it is rarely one roof. Expect three to six sheds with different heights and orientations, with skylights, vents and parapet shadows removing a share of the gross area. A shadow study turns the brochure figure into your real one, and our plant area calculator and roof load calculator give a first look at area and structural load.

Generation of about 120 units per kW per month is our planning figure for the northern belt, giving about 90,000 units a month or 10.8 lakh units a year. It is higher in Rajasthan and Gujarat and lower in the East and North East, and it varies by season. If the roof falls short, the usual alternatives are a carport, a ground-mount on spare industrial land, or a smaller rooftop plant combined with open access for the balance.

Connection voltage and inverter architecture

At this size the connection is usually on the HT side, at 11 kV, through your existing transformer bay or a dedicated one. Protection relays for reverse power, over and under voltage and frequency must coordinate with the existing scheme, and the transformer must absorb reverse flow at peak generation minus minimum load, which is Sunday afternoon for most plants. Some sites with several LT supply points can stay on the LT side, but the DISCOM and the Chief Electrical Inspector decide.

On inverters, a string architecture of roughly twelve to sixteen units in the 50 to 60 kW class is typical at this size, as is a smaller number of larger units. We usually favour strings because a failed unit costs a small share of output and is replaced from stock, whereas a failed central inverter can idle a large block of the plant. Modules, inverters and structure are described on our solar EPC pages.

The net-metering ceiling and what decides the economics

Under the Electricity (Rights of Consumers) Rules as amended in 2021, net metering is available for loads up to 500 kW or the sanctioned load, whichever is lower. Above that, the state commission's regulations decide what happens. A 750 kW plant therefore crosses a line, and the options are:

• Size to the net-metering limit (500 kW) and add the balance later or elsewhere.
• Gross metering, which pays for exported energy at a fixed rate and normally gives a lower value than self-consumption.
• Behind-the-meter captive use sized to the daytime load, with export control if the DISCOM requires.
• Open access for the balance. See open access solar for how it works.

Two further rules shape the outcome: how the state banks and settles surplus energy, and whether your sanctioned load or contract demand covers the plant size. Both differ by state, so check them before you fix the capacity. The value of a unit generated depends on whether you use it on site or export it, which is why payback is a scenario, not a single number.

Approvals, in the order they are needed

1. Check the sanctioned load and transformer headroom, then freeze the capacity.
2. Prepare the design and single-line diagram.
3. File the DISCOM application. Under the central rules as amended in February 2024, the feasibility study for systems above 10 kW must be completed in 15 days, with deemed approval if it is not.
4. For HT connection, obtain the state electrical inspector's approval of the drawings before energisation. Our CEIG guide explains the file.
5. Install and test.
6. Arrange inspection, meter installation and synchronisation. The February 2024 amendment cut the licensee's time to commission rooftop systems from 30 days to 15 days.

The module rules also matter. MNRE's office memorandum of 4 August 2026 exempts net-metering projects (defined to include gross metering and other grid-connected forms) from the cell list, ALMM List-II, only if they are commissioned by 31 December 2026; the module list, List-I, still applies. Behind-the-meter plants used solely for captive consumption by private consumers are outside both lists. Your contractor should state which applies to your plant.

There is no honest single timeline for this size. Site work on a ready roof is measured in weeks at 100 kW and grows with size and HT scope. What dominates is the procurement lead time, the DISCOM feasibility and the inspector's visit. Ask any bidder for a dated programme that separates those four items.

How Secured Engineers helps

We design in-house, take MEPF and solar under one contract, and file Fire NOC, CEIG and DISCOM net-metering applications in-house, so the HT side of a 750 kW plant is part of one scope. We work from offices in Noida (Delhi NCR) and Ludhiana, with 535+ projects across 18+ states and 89.77% repeat clients. Send your bills and sanctioned load, and we will tell you what size the connection and the rules support before you buy.

Start with the solar calculator, then WhatsApp us your last twelve bills, call +91 70099 85817, or ask for a free proposal.