Captive Solar LCOE India 2026 — Benchmark ₹2.4-3.2/kWh

Direct answer

TL;DR: A well-sited 100–500 kW captive rooftop solar plant in North India delivers energy at roughly ₹2.4–3.2 per kWh levelised over 25 years — worked from a ₹23,000–35,000/kW turnkey CAPEX, a 10–12% discount rate, and 1,350–1,550 kWh/kW/yr yield. Compare that with HT industrial grid tariffs of ₹7.5–10/kWh across Haryana, Delhi-NCR, UP and Rajasthan, and DG backup at ₹25–35/kWh. Below ₹2/kWh is not achievable for rooftop CAPEX projects at 2026 prices — anyone quoting it is quoting a utility-scale auction tariff, not your rooftop LCOE.

This page derives the solar number step by step — no black box — and shows which variables move it most.

Jump to section

How LCOE works for captive solar

LCOE (levelised cost of energy) spreads the total lifetime cost of a solar plant over the total lifetime generation, both discounted to present value. For a behind-the-meter captive rooftop system, five inputs decide the answer:

1. Turnkey CAPEX — ₹/kW installed, everything included: modules, inverters, structure, BOS, labour, net metering, CEIG approvals, and GST where applicable.
2. Specific yield — kWh generated per kW per year. North India plains run ~1,450–1,550; the Rajasthan belts reach 1,600+.
3. Degradation — output decline per year (Year-1 LID, then ~0.4–0.55%/yr for quality modules).
4. O&M cost — annual maintenance, insurance, and an inverter-replacement reserve.
5. Discount rate — your cost of capital or hurdle rate.

The formula:

LCOE = (CAPEX + Σ O&Mₜ/(1+r)ᵗ) ÷ Σ (Generationₜ/(1+r)ᵗ)

If a vendor quotes a "cost per unit" without stating these five inputs, the number is marketing, not engineering. Every claim below states its inputs.

Worked example from a ₹23,000/kW reference

We anchor on a real, verifiable turnkey rate: ₹23,000/kW (ex-GST) for qualifying CAPEX rooftop projects at 100 kW scale — the reference rate Sun Wave Technologies publishes for North India C&I projects, with ₹22,000/kW at 500 kW. GST is added at the applicable rate (5% on modules post-September 2025) and reduces the module share of the CAPEX; the net effect on LCOE is a few percent, not the 20%+ swing CAPEX itself produces.

The five inputs

The derivation

At a stricter 12% discount rate with yield at the low end (1,350 kWh/kW) and O&M at ₹10/kW/yr, the 100 kW case still lands near ₹2.3/kWh — so the band holds.

What moves the number:

• CAPEX is the dominant lever. At ₹35,000/kW (still quoted by many metro EPCs), LCOE rises to ~₹3.2/kWh. Every ₹1,000/kW of CAPEX adds roughly ₹0.09–0.11/kWh to lifetime cost.
• Yield is second. A shadow-free, well-tilted roof at 1,550 kWh/kW vs a partially shaded 1,350 kWh/kW roof swings LCOE by ~₹0.2–0.3/kWh. Get a shading analysis before signing.
• Discount rate matters less than buyers expect. Moving from 10% to 14% adds only ~₹0.4/kWh — the plant is CAPEX-dominated, not fuel-dominated.
• GST treatment (5% on modules post-Sept 2025) is a few percent on LCOE, not a deal-breaker; input credit where available narrows it further.

LCOE sensitivity table

Read the table as: CAPEX discipline beats everything else. A buyer who negotiates ₹1,000/kW off the quote does more for their LCOE than any yield optimisation.

Solar vs grid vs DG — 25-year view

The savings case rests on three comparisons:

1. vs grid (energy charge): At ₹7.5–10/kWh HT industrial tariffs with 3–5%/yr escalation, every solar unit self-consumed displaces a grid unit at a quarter to a third of the cost. A 100 kW plant generating ~1.5 lakh kWh/yr avoids roughly ₹11–15 lakh of grid purchase in Year 1. Note the ToD nuance: solar-hour rates are at least 20% below peak rates, so solar displaces the cheap grid units, not the expensive evening ones — size the plant against your daytime load, not against total consumption.
2. vs grid (demand charges): Solar rarely cuts the kVA demand charge materially (peak demand usually falls in the evening), but battery-backed systems can. See our BESS business case for NCR industrial ToD arbitrage.
3. vs DG: At ₹25–35/kWh, DG is roughly 10x the cost of captive solar. Where DG runtime is driven by daytime outages, solar plus modest storage displaces the most expensive units first. See on-grid vs off-grid vs hybrid for factories.

Grid parity for C&I rooftop solar is not a forecast — it happened years ago. The question buyers should ask is not whether the LCOE beats the grid, but how much of your daytime load the plant can serve, and at what verified CAPEX.

Common LCOE mistakes buyers make

1. Comparing LCOE to the average tariff instead of the solar-hour tariff. Under ToD billing, solar displaces the cheaper daytime units. Model savings at solar-hour rates.
2. Ignoring escalation. Grid tariffs escalate 3–5%/yr; solar O&M escalates ~5%. The gap widens every year — a Year-1 ₹4–5/kWh saving becomes ₹7–9 by Year 15.
3. Accepting a "cost per unit" without inputs. Demand the five inputs above. If the vendor's specific-yield claim cannot be traced to a GHI source (NASA/Meteonorm/NREL data for your pincode), treat it as a guess.
4. Forgetting inverter replacement. Inverters last 10–12 years; a 25-year plant buys 1–2 replacement cycles. Fold a ₹0.15–0.25/kWh reserve into the LCOE (we have, within the ₹7–9/kW/yr O&M line).
5. Confusing LCOE with OPEX tariff. A RESCO/OPEX developer sells at ₹3.5–4.5/kWh because that price must cover their financing, margin and risk — your self-owned LCOE is lower. Both can be true; see third-party sale vs group captive and the RESCO OPEX model.
6. Sizing to consumption instead of load shape. Oversizing beyond daytime demand pushes expensive exports under net-billing states; see net metering vs net billing vs gross metering.

Frequently Asked Questions

What is the LCOE of rooftop solar in India in 2026?

For well-sited 100–500 kW captive C&I rooftop plants in North India, ₹2.4–3.2/kWh levelised over 25 years is a defensible 2026 benchmark, derived from ₹23,000–35,000/kW turnkey CAPEX and 1,350–1,550 kWh/kW/yr yield. NITI Aayog's MSME decarbonisation roadmap (Feb 2026) separately reports realised rooftop solar tariffs of ₹3.8–6.5/kWh against grid tariffs of ₹5.6–9.9/kWh — the gap to our bottom band is financing structure and risk premium, not physics.

Why is my EPC's "cost per unit" higher than these numbers?

Because it probably is not an LCOE. EPC cost-per-unit figures often bundle O&M contracts, financing, or warranties, or simply quote a PPA-style tariff. A transparent LCOE derivation needs exactly five inputs — CAPEX, yield, degradation, O&M, discount rate — and should be reproducible from your own quote sheet.

Is ₹2/kWh possible for rooftop solar?

Not for rooftop CAPEX projects at 2026 prices. Sub-₹2/kWh figures come from utility-scale auctions at 100+ MW scale with trackers and no rooftop constraints. A rooftop plant pays for structure, waterproofing, roof access, and a smaller inverter base — that premium is worth roughly ₹0.4–0.8/kWh.

Does LCOE include GST and subsidies?

Our benchmark excludes GST because input-credit availability varies by buyer; including 5% GST on modules (post-Sept 2025) adds a few percent to LCOE. There is no central CFA subsidy for C&I rooftop solar — PM Surya Ghar is residential-only — so no subsidy adjustment applies. See commercial solar subsidy reality check.

How does captive solar LCOE compare with open access?

Open-access (off-site) solar adds wheeling, banking, CSS and additional surcharges on top of generation cost — in most North Indian states this lands the landed cost at ₹3.5–5/kWh, competitive with but not reliably cheaper than a good rooftop. Rooftop also avoids OA approval timelines entirely. See the open access state comparison hub and the Haryana OA charges guide.

What discount rate should I use for my own calculation?

Your own cost of capital. An MSME borrowing at 11–13% should use that, not 8%. The band is robust: even at 14% the LCOE stays under ₹2.8/kWh at reference CAPEX.

---

Sources: NITI Aayog MSME decarbonisation roadmap via Mercom India (Feb 2026) — rooftop solar ₹3.8–6.5/kWh vs grid ₹5.6–9.9/kWh; Mercom India Q1 2026 Rooftop Solar Market Report — CAPEX model share, segment shares; Ember (Apr 2026) — state-level solar-plus-storage LCOE modelling; Sun Wave Technologies reference pricing (₹23,000/kW at 100 kW, ₹22,000/kW at 500 kW, ex-GST, verified Sep 2026). Worked-example arithmetic is ours; replicate it from the five inputs above.