100kW Solar Panel System Price with Subsidy in India (2025)

Thinking about installing a 100 kW solar panel system in 2025? Great choice. A 100 kW plant is the sweet spot for factories, hotels, hospitals, schools/colleges, large offices, warehouses, and high-load commercial buildings. Below is a simple, no-nonsense guide to the price, incentives/subsidy reality, ROI, and a ready-to-use cost breakdown—written to help you make a quick, confident decision.

Quick Summary (TL:DR)

• Indicative price in 2025 (C&I rooftop): ₹35–₹55 lakh before taxes and approvals for a quality 100 kW system (final figure depends on modules/inverters/structure, site complexity, and warranty scope).
• Central subsidy: Not available for commercial & industrial (C&I) systems like 100 kW. MNRE’s national subsidy is for residential households only, under the PM Surya Ghar scheme.
• What you DO get: Accelerated Depreciation @ 40% for businesses + state net-metering benefits (where applicable).
• Typical payback: 3–5 years for most C&I consumers with good daytime consumption and reasonable tariffs.

How Much Does a 100 kW Solar System Cost in 2025?

Market referenced C&I pricing across reputable installers in 2025 generally falls in the ₹35,000–₹40,000/kW band for industrial rooftops, which puts 100 kW around ₹35–₹40 lakh for a standard build. With premium components (n-type TOPCon/HJT modules, string+controller redundancy, heavy-duty wind structures, extended O&M), budgets can reach ₹50–₹55 lakh. Outliers (complex roofs, corrosion-prone sites, high-spec warranties) can be higher.

Note: Older or different estimates sometimes quote ₹60–₹80 lakh for 100 kW depending on scope and era of pricing. Use fresh, apples-to-apples quotes that specify module tech, BOS quality, and service terms.

What About Subsidies for 100 kW?

Here’s the clear picture for 2025:

• Central subsidy (MNRE) under PM Surya Ghar: Muft Bijli Yojana is for residential households only (up to 3 kW slab benefits). Commercial and industrial consumers are not eligible for the national CFA.
• Many articles and portals also explicitly state that C&I users are not eligible for the national rooftop subsidy, they instead leverage tax benefits (Accelerated Depreciation) and net metering where available.
  
  

So, what benefits can a business still claim?

• Accelerated Depreciation (AD): Businesses can typically claim 40% depreciation on solar assets, improving post-tax returns and shortening payback. 
• State/Discom policies: Net-metering/Group net-metering/Behind-the-meter self-consumption—subject to your state’s regulations. (Rules and caps vary by state and consumer category.)
• Heads-up: Residential consumers get slab-based subsidy (e.g., up to ₹78,000 for ≥3 kW), but this is not applicable to a typical 100 kW C&I plant.

A Practical 100 kW Cost Breakdown (Illustrative)

Below is a realistic template for a quality 100 kW rooftop plant. Adjust percentages based on your chosen specs:

Taxes & approvals are extra as per prevailing norms.

Generation and Savings: What to Expect

• Annual generation (100 kW rooftop): 1.4–1.6 lakh kWh/year in many Indian locations, assuming decent PR, minimal shading, and good O&M.
• If grid tariff is ₹8/kWh (illustrative C&I tariff), gross annual savings can be ₹11–₹13 lakh.
• Payback: With ₹35–₹55 lakh capex and Accelerated Depreciation, payback commonly lands around 3–5 years, and sometimes faster for high-tariff consumers.

Actual numbers vary by state irradiation, rooftop orientation, losses, downtime, and tariff slab.

Simple ROI Snapshot (Illustrative)

• System size: 100 kW
• Capex (quality build): ₹45,00,000 (example)
• Annual generation: 1,50,000 kWh
• Tariff offset: ₹8.0/kWh → ₹12,00,000/yr gross savings
• O&M + insurance: ₹1,00,000/yr
• Net savings (pre-tax): ₹11,00,000/yr
• Payback (naïve): 4.1 years (before AD tax impacts)
• With AD (tax shield): Effective payback can improve notably (consult your CA).

Choosing Components That Keep Lifetime Costs Low

1. Module Tech:

• n-type TOPCon/bifacial (higher efficiency, better low-light, strong for space-constrained roofs).

• Glass-glass for harsh/coastal/chemical environments.

• Insist on reliable PAN files, IEC/BIS certifications, and degradation warranties (e.g., ≤1% first year, then ≤0.4–0.5%/year).

2. Inverters:

• String inverters with multiple MPPTs suit split roofs and reduce mismatch losses.

• Look for DC/AC SPD, AFCI (arc-fault) features, remote monitoring, and strong service footprint.

• Keep a spare inverter or plan for quick-swap to minimize downtime.

3. Structures & Wind Design:

• Verify wind-speed compliance as per local code; request structural calculations.

• For sheet-metal roofs, use tested penetration/seam clamps, corrosion-resistant fasteners, proper sealing.

4. Cables & Protections:

• UV-resistant DC cables, proper routing, string fusing where needed.

• Lightning protection and dedicated earthing—tested and documented.

5. Monitoring & O&M:

• String-level monitoring helps spot faults quickly.

• Define cleaning frequency, safety SOPs, replacement SLAs, and spare parts list in the contract.

Net-Metering & Policy Notes

• C&I net-metering/group net-metering rules vary by state and are periodically revised (caps on system size, settlement method, banking rules). Always check your state DISCOM/energy department circulars during the proposal stage.
• Residential schemes (like PM Surya Ghar) are actively promoted—for context only, these offer slabs up to ₹78,000 subsidy for household systems up to 3 kW, sometimes topped up by states (e.g., certain local top-ups announced in 2025). This does not change the non-eligibility of C&I 100 kW plants for national subsidy.

Model BoQ for a 100 kW Rooftop (Illustrative)

• Modules: 160–170 panels @ 600–650 Wp each (adjust to latest Wp bins)
• Inverters: 3–4 string inverters (or a single central with DC combiner, as designed)
• Structure: GI/Aluminum with wind design & anti-corrosion treatment
• Electrical: DC combiner boxes (if used), ACDB, earthing, LA, cables, conduits, tagging
• Monitoring: Data logger/SCADA with web dashboard & mobile app
• Docs & Compliance: SLDs, earthing tests, PR test, handover kit
• Services: Design-engineering, installation, testing-commissioning, liaison

Step-by-Step: From Quote to Commissioning

1. Site audit & feasibility: Roof strength, shading, access, cable path, earthing plan.
2. Energy study: Load profile, sanctioned load/contract demand, net-metering feasibility.
3. Design & proposal: PVSyst/PV*SOL-based yield, component list, warranties, SLAs.
4. Order & permits: Utility applications, CEIG (if required), safety clearances.
5. Installation: Structure, module mounting, stringing, terminations, earthing, LA.
6. Testing & commissioning: IV curves (if planned), protections test, synchronisation.
7. Handover & training: Manuals, O&M SOPs, dashboards, emergency procedures.
8. Ongoing O&M: Cleaning, inspections, fault response, periodic reports.
   
   

Frequently Asked Questions (FAQs)

1) What is the realistic 2025 price for a 100 kW rooftop system?
₹35–₹55 lakh before taxes for quality C&I builds; final price depends on module tech, inverter topology, structure quality, warranties, and site complexity.

2) Is there any central subsidy for a 100 kW C&I plant?
No. The national subsidy is for residential households (PM Surya Ghar). C&I consumers are not eligible for this CFA.

3) What benefits can businesses claim instead of subsidies?
Accelerated Depreciation (~40%) under the Income-tax Act (consult your CA), plus net-metering and other state-level policy benefits where available.

4) How much energy will a 100 kW system generate?
Typically 1.4–1.6 lakh kWh/year on well-designed rooftops with decent irradiation and maintenance.

5) What is the payback period?
Usually 3–5 years for C&I users with strong daytime consumption and fair tariffs; AD can further improve returns.

6) Which modules should I choose—Mono-PERC or n-type TOPCon/HJT?
If budget allows, n-type TOPCon/HJT offers higher efficiency and better low-light performance; Mono-PERC remains value-for-money. Match selection to space, environment, and ROI goals.

7) String or central inverter?
For split/irregular roofs, string inverters with multiple MPPTs reduce mismatch losses and simplify maintenance.

8) Can I do net-metering for 100 kW?
Subject to your state’s regulations (caps, settlement rules, banking). Always verify with your DISCOM before ordering.

9) What warranties should I demand?

• Product: 10–12 years (modules), 5–10 years (inverters), structure warranty per spec.
• Performance: e.g., 25-year linear power output warranty for modules (check exact terms).
• Service/O&M: Defined response times, spares, and reporting.

10) How do I keep lifetime costs low?
Invest in robust structures, proper earthing & surge protection, and string level monitoring; they prevent expensive failures and lost generation.