100 kW solar plant cost: ₹40–50 lakh, engineered honestly
A 100 kW rooftop system in India runs ₹40–50 lakh turnkey (₹40,000–50,000/kW) 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.
15+ years · 535+ projects · Approvals in-house · ISO 9001:2015
100 kW plant — the working numbers
| Indicative turnkey cost | ₹40–50 lakh |
| Per-kW benchmark | ₹40,000–50,000 |
| Roof required | ~10,000 sq.ft shadow-free |
| 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 | 3.5–4.5 years |
Indicative North-India figures at ~120 units/kW/month — 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.
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.
⚠ 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.
100 kW solar plant — questions we actually get
What does a 100 kW solar plant cost in India?
Indicatively ₹40–50 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 North India (≈120 units/kW/month, 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.
Other sizes: 100 kW · 500 kW · 1 MW | Full service: Commercial & Industrial Solar EPC
Budgeting a 100 kW plant?
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