100 kW solar plant cost: ₹28–32 lakh, engineered honestly
A 100 kW rooftop system in India runs ₹28–32 lakh turnkey — a price of ₹28,000–32,000 per kW, excluding GST — as of 2026, best suited to facilities with ₹1–1.5 lakh/month electricity bills. Here's what that buys, what it generates, and the engineering that changes at this size.
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100 kW plant — the working numbers
| Indicative turnkey cost | ₹28–32 lakh excl. GST |
| Per-kW benchmark | ₹28,000–32,000 excl. GST |
| Roof required | ~10,000 sq.ft shadow-free |
| Land, if ground-mounted | ~0.4 acres (0.35–0.5) · working |
| Generation (monthly avg.) | ~12,000 units |
| Generation (annual) | ~1.44 lakh units |
| Bill offset potential | ~₹1.0–1.1 lakh/month at ₹9/unit |
| Indicative payback | 2.2–2.5 years |
Indicative figures at ~120 units/kW/month, the northern band — Rajasthan and Gujarat run higher, the East and North East lower; pick your region in the solar plant cost calculator for a figure that matches your site. Seasonal variation (including the winter fog dip) is real and belongs in any honest model.
Cost split of a turnkey 100 kW system
| Solar modules (ALMM Tier-1) | 50–58% |
| Inverters & monitoring | 9–12% |
| Mounting structure | 8–11% |
| Cabling, protection & BOS | 10–13% |
| Installation, T&C | 7–10% |
| Approvals, metering & misc. | 2–4% |
A quote materially below the band usually removes scope — structure gauge, protection, or approval liability — rather than adding efficiency. Compare BOQs line by line, or send us one to counter-check.
What the 100 kW price above assumes
A solar cost figure means nothing without the three assumptions underneath it. Quoted ranges differ between sources mostly because these were set differently, not because one supplier is cheaper than another.
You own the plant
Every figure on this page is exclusive of GST, which is charged on top. We quote ex-GST because most C&I buyers are GST-registered and treat the tax separately from project cost — but whether you can offset it as input credit depends on your registration and how the asset is used, so take that one to your tax advisor rather than our word. When you compare quotations, check each one states the same basis: an inclusive and an exclusive quote are not the same number.
₹28–32 lakh is the CAPEX number — you fund it, you own the asset, the generation and the depreciation. Under an OPEX or RESCO arrangement you fund nothing and buy the units at an agreed tariff, which is a different question with a different answer. The ten-year comparison puts both on the same page; the glossary entry is the short version.
It is a rooftop system
Ground-mount is priced differently — land, civil foundations, boundary and the evacuation run are added, while access, cleaning and O&M get easier and cheaper for the life of the plant. On a constrained or fragmented roof the comparison is worth running properly rather than assuming the roof wins because it is free.
Standard-class modules and structure
Module technology and structure specification move you within the band, not out of it. What moves a quote below the band is almost always scope leaving it — structure gauge, protection, monitoring or approval liability. Read the BOQ, not the headline.
The final number comes from a site survey — roof structure and shadow-free area, sanctioned load and transformer headroom, and the state's current net-metering position. Anything quoted before those are known is a starting point for a conversation, not a price.
The engineering story at this size
The 100 kW class is the C&I entry point: small factories, cold stores, schools, hospitals and mid-size commercial buildings. Approvals are the standard rooftop net-metering flow, installation is 3–5 weeks on a ready roof, and the engineering risk concentrates in just two places — roof structure and metering paperwork.
Grid interconnection
Usually LT-side (415 V) or 11 kV depending on your connection — the simplest interconnection case, with net metering under most DISCOMs' standard rooftop process.
Inverter architecture
Typically 2–4 string inverters (25–50 kW class) — no central inverter economics at this size, and string-level monitoring makes fault isolation trivial.
Approvals
DISCOM net-metering/captive registration and CEIG approval filed in-house, in parallel with procurement — approvals are our trade, not a subcontracted liaison job. The full scope, stage by stage, is on our solar EPC service page.
⚠ Sanctioned-load cap
Most DISCOMs cap net-metered capacity at or near your sanctioned load. A 100 kW plant on an 80 kW sanction stalls at the application stage — check headroom first with our sanctioned-load tool.
⚠ Roof reality
10,000 sq.ft on paper is rarely 10,000 usable — skylights, vents and parapet shadows typically shave 10–20% off. Shadow analysis before design, not after.
⚠ Single-phase of paperwork
At this size the DISCOM file is standard — but one mismatched load detail still restarts the clock. It's why we file approvals in-house.
Module eligibility is a 2026 watch-out of its own: for a net-metered or open-access plant, ALMM List-I applies and the List-II (cell) exemption turns on whether the plant commissions by 31 December 2026 — see the ALMM List-II commissioning guide before fixing a module.
100 kW solar plant — questions we actually get
What does a 100 kW solar plant cost in India?
Indicatively ₹28–32 lakh turnkey for a rooftop C&I system — module choice, structure type (RCC vs metal shed), cable runs and metering scope set where you land in that band. Treat any single-number quote given without a site survey as marketing, not engineering.
How much does 100 kW generate and save?
Around 12,000 units a month in the northern belt (≈120 units/kW/month; roughly 135 in Rajasthan and Gujarat, nearer 105–115 in the East and North East), with seasonal swing — winters dip, summers peak. At a ₹9/unit blended tariff that's roughly ₹1 lakh+/month offset if your daytime consumption absorbs it.
How much roof does 100 kW need?
Plan ~10,000 sq.ft of shadow-free area (~100 sq.ft/kW). East-west sheds, skylights and rooftop utilities reduce usable area — a shadow study converts the brochure number into your real one.
How long does a 100 kW installation take?
Typically 3–5 weeks of site work on a structurally ready roof, plus DISCOM/net-metering timelines that vary by state — we run approvals in parallel with procurement so paperwork never becomes the critical path.
How much land does a 100 kW solar plant need?
On the ground, about 0.4 acres, and 0.35–0.5 acres in practice. The Indian rule of thumb is roughly 4 acres per MW; module efficiency, inter-row spacing and terrain move it. On a roof it is about 10,000 sq.ft shadow-free. A ground-mounted plant is priced differently from the rooftop band on this page, because land, civil foundations, fencing and the evacuation line are added. The solar plant area calculator shows the working.
Other sizes: 100 kW · 250 kW · 500 kW · 1 MW | Full service: Commercial & Industrial Solar EPC · Solar EPC — scope & approvals
Send last month's electricity bill with your enquiry. Sanctioned load, tariff and actual consumption are all on it — they decide whether a 100 kW plant is the right size for your site, and they are what turns the band above into a number for your roof.
Budgeting a 100 kW plant?
Send your electricity bill and roof details — our estimation team returns an engineered budget with the cost split above filled in for your site, free.
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