ALMM and inverter compliance: MNRE’s current ALMM page publishes solar PV module and cell lists, not an inverter list. Verify the inverter’s exact model documents and applicable scheme or DISCOM requirements separately.
What is CAPEX
CAPEX, Capital Expenditure, is the total upfront cost of designing, procuring, installing and commissioning a solar PV project. It is one of the two big cost categories in project economics, alongside OPEX (operating expenditure). C&I buyers deciding between owning the asset outright or paying for power as a service should see our CAPEX vs OPEX decision guide before committing to a structure. For solar specifically, capex dominates the lifecycle cost structure because operating costs are low.
Indian solar capex includes modules, inverter, mounting structure, DC and AC cables, transformer, switchgear, civil work, labour, project management, financing during construction, contingency, taxes and connection charges. For utility-scale plants land cost is also included. For rooftop projects existing roof eliminates that line item.
Capex per watt has fallen dramatically over the past decade. Utility solar fell from ₹15 crore per MW in 2012 to ₹3.5 to ₹4.5 crore per MW in 2026. The collapse was driven primarily by silicon module price reduction, with BOS and labour also falling.
CAPEX explained simply
To build a solar plant, you need to buy panels, inverters, racking, wires, transformers, and pay for installation. Add it all up. That total is the capex. For a 1 MW utility plant in India today, that is roughly ₹3.5 to ₹4.5 crore. For a 3 kW home rooftop, around ₹1.65 lakh.
Why CAPEX matters
Project budgeting. The customer needs to know the cost before committing.
Financial modelling. LCOE, IRR and payback period all start from capex.
Tariff discovery. SECI tender economics rest on capex assumptions.
PPA negotiation. The developer must recover capex through PPA revenue.
Customer financing. Loans size against capex, and buyers comparing lenders can start with our best bank for solar loan comparison.
Subsidy quantification. PM Surya Ghar caps capex eligibility for subsidy, with the exact numbers broken down in our PM Surya Ghar subsidy calculator guide.
How CAPEX is calculated
Technical deep dive
Indian solar capex breakdown (utility-scale, ₹/W, 2026)
| Component | ₹/W | % of total |
|---|---|---|
| Modules (ALMM bifacial) | 17 to 22 | 45 to 50 |
| Inverter (central or string) | 3.5 to 4.5 | 8 to 10 |
| Mounting structure | 4 to 5 | 10 to 12 |
| DC and AC cables | 2 to 3 | 5 to 7 |
| Transformer and switchgear | 2.5 to 3.5 | 6 to 8 |
| Civil work | 2 to 3 | 5 to 7 |
| Labour and installation | 2 to 3 | 5 to 7 |
| Project management, taxes, contingency | 3 to 5 | 8 to 11 |
| Total | 36 to 45 | 100 |
Indian rooftop capex breakdown (residential 3 kW, ₹/W, 2026)
| Component | ₹/W |
|---|---|
| Modules (ALMM half-cut TOPCon) | 16 to 22 |
| Inverter (string single-phase) | 6 to 9 |
| Mounting structure | 4 to 6 |
| DC and AC cables | 3 to 5 |
| Labour and installation | 4 to 7 |
| Bidirectional meter, BOS, taxes | 3 to 6 |
| Total before subsidy | 36 to 55 |
| PM Surya Ghar subsidy | -26 (₹78,000 for 3 kW) |
| Net cost | 10 to 29 |
Capex trajectory
| Year | Indian utility capex (₹ Cr/MW) |
|---|---|
| 2012 | 12 to 15 |
| 2016 | 6 to 8 |
| 2019 | 4 to 5 |
| 2022 | 3.5 to 4.5 |
| 2024 | 3.5 to 4.3 |
| 2026 | 3.5 to 4.5 |
The trajectory plateaued around 2020 to 2024, with mild upward pressure from raw material prices balanced by manufacturing scale.
Capex by project type
| Project type | Capex (₹/W) |
|---|---|
| Utility ground-mount | 35 to 45 |
| Utility floating | 50 to 70 |
| Utility tracker bifacial | 40 to 50 |
| C&I rooftop | 35 to 55 |
| Residential rooftop pre-subsidy | 40 to 70 |
| Residential post-PM Surya Ghar | 10 to 30 |
| Off-grid solar + battery | 60 to 120 |
Real-world applications
PPA tariff bidding under SECI tenders.
Customer cost estimation for rooftop solar.
State SERC tariff order benchmarking.
Bank loan sizing.
PM Surya Ghar subsidy disbursement calculation.
Investor pitch documents, typically built on the same solar financial modeling inputs used for PPA bidding.
Advantages
Single upfront cost easy to communicate.
Standardised across the industry.
Direct input to financial models.
Captures total project investment.
Limitations
Hides lifecycle cost (including O&M and replacement).
Sensitivity to module price volatility.
Project-specific variation around averages.
Does not differentiate quality between low-cost and premium installations.
Common problems
Capex overruns during construction. Buffer of 3 to 5 percent contingency mitigates.
Hidden costs (connection, transformer upgrade) discovered late.
Module price volatility affecting bid economics.
GST and customs duty changes during construction.
Quality compromises to hit aggressive capex targets.
Best practices
Use detailed bills of quantity, not lump sum estimates.
Include 3 to 5 percent contingency.
Validate prices against current ALMM-listed brands.
Factor in transformer upgrade and connection charges separately.
Plan for monsoon delays in construction schedule.
Track capex against budget through project phases, ideally with dedicated project management consultancy for larger builds.
Comparison: capex by configuration
| Configuration | Capex (₹/W) | Notes |
|---|---|---|
| Mono PERC fixed-tilt monofacial | 36 to 42 | Baseline |
| Mono PERC fixed-tilt bifacial | 37 to 44 | +1 to 2 ₹/W |
| Mono TOPCon fixed-tilt bifacial | 38 to 45 | +2 to 4 ₹/W |
| Tracker bifacial TOPCon | 42 to 50 | +6 to 8 ₹/W, +20 to 25% yield |
| HJT bifacial | 44 to 55 | Premium |
Indian market context
PLI scheme reduced reliance on imported cells and modules. Domestic capex has stabilised.
PM Surya Ghar subsidy effectively halves residential capex for systems up to 3 kW.
Major Indian EPCs publish typical capex bands for tender comparison.
Standards and certifications
| Standard | Scope |
|---|---|
| CERC benchmark capex methodology | Tariff order basis |
| MNRE technical specifications | Component requirements |
| BIS certification | Quality compliance |
| GST and customs frameworks | Tax components |
Common mistakes
Comparing capex across projects with different scope.
Excluding transformer or connection charges.
Underestimating monsoon delay impact.
Ignoring contingency.
Treating PM Surya Ghar subsidy as discount rather than reimbursement.
Using outdated capex assumptions in financial models.
Key takeaways
CAPEX is the upfront cost of building a solar project. Indian utility-scale capex sits at ₹3.5 to ₹4.5 crore per MW (₹35 to ₹45 per Wp). C&I rooftop at ₹35 to ₹55 per Wp. Residential rooftop ranges ₹40 to ₹70 per Wp pre-subsidy, dropping to ₹10 to ₹30 post PM Surya Ghar. Capex has fallen 70+ percent since 2012 and has stabilised. Module, inverter, structure and labour are the four major components.
Further reading
For how CAPEX plays out in real projects, these guides go deeper:
- Solar CAPEX vs OPEX: The C&I Buyer Decision Guide
- Zero Cost Solar India: RESCO & OPEX Models
- Solar CAPEX vs OPEX: Which Model Fits Your Business?
- Solar RESCO Model India: Guide for C&I Buyers
Sources
- CERC Tariff Regulations 2024 and benchmark capex methodology.
- IRENA Renewable Power Generation Costs in 2024.
- NREL Annual Technology Baseline 2024.
- BloombergNEF Solar PV Cost Trends 2024.
- IEA Renewables 2024.
- SECI Tender Documents and Discovered Tariffs.
- MNRE PLI Scheme Implementation Reports.
- PM Surya Ghar Muft Bijli Yojana scheme guidelines.
- Mercom India Solar Market Reports.
Frequently Asked Questions
What is CAPEX in simple words?
What is the current Indian solar capex?
What does capex include?
CAPEX vs OPEX, what is the difference?
Is land cost included in capex?
Has solar capex fallen?
Why is rooftop capex higher than utility per watt?
What is the typical PM Surya Ghar capex for 3 kW?
Does capex include taxes?
What is capex per watt?
Is capex same as project cost?
Does ALMM affect capex?
Is bifacial capex higher?
What is contingency in capex?
Does capex include financing cost?
From the Blog
Co-founder & CEO driving Qbits Energy's product strategy and growth across India.