100 kW Solar System Cost in India (2026)

Direct answer

A 100 kW commercial rooftop solar system in India costs about Rs 23 lakh (Rs 23,000 per kW) ex-GST for a qualifying CAPEX project on Sun Wave Technologies' reference pricing. That is an all-in turnkey figure — modules, inverters, structure, cabling, installation, and DISCOM liaison included — before GST and before accelerated depreciation benefits. At typical North-India industrial tariffs of Rs 7-10 per unit, the system generates roughly 1.4-1.5 lakh units a year, saving Rs 10-15 lakh annually, and pays back in about 2-4 years for a tax-paying business once 40% accelerated depreciation is claimed.

TL;DR: Reference cost Rs 23 lakh ex-GST at Rs 23,000/kW | ~1.4-1.5 lakh units/year | Rs 10-15 lakh annual savings at Rs 7-10/unit tariffs | payback ~2-4 years with accelerated depreciation | final price follows site survey and engineering scope.

A 100 kW system sits at the entry point of serious industrial solar: it is the smallest size at which Tier-1 EPC economics, HT/LT industrial tariffs, and tax benefits all align, and the most common first project for factories, warehouses, and commercial buildings in Delhi-NCR, Haryana, Rajasthan, and UP. This guide gives you the complete cost picture — what you pay, what you save, what moves the price, and how to compare quotes on a like-for-like basis.

What the Rs 23 lakh covers

Sun Wave's Rs 23,000/kW reference rate for a 100 kW CAPEX rooftop project is a complete, usable-plant figure. Here is what sits inside it and what sits outside.

Inside the reference price

The exact split varies with roof type (RCC vs metal sheet), site access, and electrical integration distance to your LT panel. Use the split to compare quotes: when one EPC's number is materially below another's, check whether a line item — structure quality, inverter class, earthing scope — has been shaved, not just whether the total is lower.

What is not in the base number

• GST: 5% on solar modules post-September 2025 and standard rates on balance-of-system items; GST input credit may apply for GST-registered businesses.
• Net metering fees and load enhancement charges: DISCOM-specific; some states allow these to be billed with the first electricity bill post-commissioning.
• Optional structural upgrades: if a structural assessment calls for roof strengthening, that is quoted separately after the survey.
• O&M beyond the initial warranty period: budget separately (see O&M costs below).

How much a 100 kW system generates and saves

Generation is the driver of every rupee that follows. A 100 kW system in North India typically produces 4-4.5 units per kW per day averaged over the year — roughly 1.4-1.5 lakh units a year.

Two levers dominate your actual number. First, the tariff you actually pay — every rupee of tariff shortens payback; a plant paying Rs 9/unit recovers cost roughly 8-12 months faster than an identical plant at Rs 7/unit. Second, self-consumption: units consumed on-site replace grid power at full tariff, while exported units earn the DISCOM's net-metering or feed-in credit, which is lower. A factory with strong daytime load captures the full value.

For the detailed yield figures by city, see our solar units generated per kW guide for North Indian cities.

Payback and returns for a 100 kW system

Simple payback (no tax benefits)

Rs 23 lakh ÷ Rs 10-15 lakh annual savings = ~3-5 years. Tariff escalation of 5-8% a year shortens this in practice, because savings grow every year while the investment is fixed.

Payback with accelerated depreciation

Tax-paying Indian businesses can claim 40% accelerated depreciation on solar assets under Section 32(1)(iia) of the Income Tax Act. For a company in the 25-30% tax bracket:

• Year-1 depreciation deduction: 40% of Rs 23 lakh = Rs 9.2 lakh
• Tax shield at 25% tax: ~Rs 2.3 lakh
• Effective net investment: ~Rs 20.7 lakh

That compresses payback to roughly 2-4 years, and pushes project IRR into the high teens to mid-20s percent range — one of the highest-return capital deployments available to an Indian manufacturer. For the full tax mechanics and how Section 115BAA interacts with it, see our accelerated depreciation vs 115BAA guide and the industrial tax-benefits guide.

A worked example

These are illustrative figures for planning, not guarantees — your tariff, load profile, and tax position move the result.

What changes the price of a 100 kW project

For the deeper view of roof suitability, see our roof structural load assessment guide.

100 kW vs other sizes

If your roof and load support 500 kW, the per-kW economics improve — the full size-band picture from 100 kW to 1 MW+ is in our commercial solar cost guide, with size-specific detail in the 1 MW solar plant cost guide.

What a fair quote looks like

When you collect quotes for a 100 kW project, insist on:

1. Itemised scope — modules (make, model, wattage, ALMM status), inverter (make, model), structure (material, coating), cabling, earthing, approvals ownership.
2. Performance ratio guarantee — a contractual PR commitment with liquidated damages for shortfall.
3. Warranty pass-through — 25-year module performance warranty and 10-year inverter warranty, in writing.
4. O&M terms — cleaning frequency, monitoring, response SLAs, and price.
5. Two commercial paths — CAPEX price and a RESCO/OPEX alternative (zero upfront, pay per unit) so you can compare lifetime value. See our RESCO/OPEX model guide.

For the full evaluation framework, see our how to choose a solar EPC company guide and how to read an EPC quote.

O&M costs after commissioning

Annual operations and maintenance for a C&I rooftop plant in India typically runs Rs 2,000-4,000 per kW per year (about 1-2% of capex), covering scheduled cleaning, monitoring, preventive electrical checks, and inverter upkeep; inverter replacement is budgeted as a separate lifecycle reserve (typically in years 10-12). Our full solar O&M guide for industries details what contracts cover and what they exclude, and the cleaning schedule guide covers the single biggest performance lever.

Government support for a 100 kW commercial system

• No central capital subsidy for C&I — PM Surya Ghar assistance is residential-only. Our commercial solar subsidy guide explains what C&I buyers actually get.
• 40% accelerated depreciation — the headline tax benefit, detailed above.
• GST treatment — 5% on modules post-Sept 2025; input credit flow for registered businesses.
• Net metering — availability and caps vary by state and DISCOM; our state net-metering guides (Haryana DHBVN, UHBVN, UPPCL, Rajasthan, Delhi) carry the current rules.

Regional notes for Sun Wave's service area

Sun Wave installs 100 kW-class systems across Delhi-NCR, Haryana, Rajasthan, Uttar Pradesh, and West Bengal. Region-specific tariff and net-metering context is in our location guides: Faridabad deep dive, Gurugram, Noida, Jaipur, and Kolkata/West Bengal.

Frequently Asked Questions

How much does a 100 kW solar system cost in India in 2026?

About Rs 23 lakh ex-GST (Rs 23,000 per kW) for a qualifying CAPEX rooftop project on Sun Wave's reference pricing. The final price follows the site survey and agreed engineering scope — roof type, structure, electrical integration, and equipment specification move the number up or down from the reference.

How many units does a 100 kW solar system generate per day?

In North India, roughly 400-450 units per day averaged across the year (4-4.5 units per kW per day), or about 1.4-1.5 lakh units a year. Summer months run higher and monsoon months lower.

Is a 100 kW solar system worth it for a factory?

For a factory paying Rs 7-10 per unit with daytime load, yes — typical payback is 2-4 years with accelerated depreciation, after which the plant delivers essentially free daytime electricity for the remaining 20+ years of its life.

Can I get a government subsidy on a 100 kW commercial solar system?

No central capital subsidy applies to commercial or industrial systems — PM Surya Ghar is residential-only. The C&I benefit is 40% accelerated depreciation under Section 32, plus GST input credit where applicable, which for a tax-paying business usually exceeds the value of the residential subsidy.

How much roof area does a 100 kW solar system need?

About 8,000-10,000 sq ft of usable roof (roughly 80-100 sq ft per kW), after deducting AHU plant rooms, skylights, walkways, and shadow buffers.

What is the payback period for a 100 kW solar system in India?

Roughly 3-5 years simple, and 2-4 years once 40% accelerated depreciation is claimed by a tax-paying company in the 25-30% bracket. Higher tariffs and higher daytime self-consumption shorten it; low tariffs and heavy night-shift load lengthen it.

100 kW vs 500 kW solar system — which is better?

If your roof and load support 500 kW, the per-kW cost drops (Sun Wave's reference is Rs 22,000/kW at 500 kW vs Rs 23,000/kW at 100 kW) and the same fixed costs spread over more units. But do not oversize beyond daytime load — exported units earn less than self-consumed units in most state net-metering frameworks.

Does a 100 kW system need CEIG approval?

Requirements vary by state and connection voltage. LT-connected systems are often exempt or fast-tracked; HT-connected systems above 100 kW typically need CEIG drawing approval before energization. Our CEIG approval guide covers the process end to end.

Sources

• Sun Wave Technologies reference pricing for qualifying CAPEX rooftop projects — Faridabad industrial solar page (Rs 23,000/kW at 100 kW, Rs 22,000/kW at 500 kW, ex-GST, verified September 2026)
• Income Tax Act Section 32(1)(iia) — accelerated depreciation provisions
• MNRE / DISCOM rooftop-solar regulations for state net-metering rules (linked in text)
• Industry O&M cost benchmarks (1-2% of capex per year, Rs 2,000-4,000/kW/year class) for C&I rooftop plants in India, 2025-2026