Home › Research › Aluminium Captive Coal CPP Renewable Transition India
Aluminium · DecarbonisationIndia’s Aluminium Smelters and the Captive Coal CPP Question: Why the Economics of Switching to Renewables Are Better Than Most CFOs Realise
India’s aluminium sector runs approximately 9,500 MW of captive coal power — enough to power a mid-sized country. This captive fleet delivers the round-the-clock, high-quality electricity that Hall-Héroult smelting requires, at costs historically competitive with grid power, and with the supply security that an energy-intensive continuous process cannot compromise. It is also the source of approximately 80% of the sector’s greenhouse gas emissions. Under CCTS, those emissions carry a compliance cost. Under CBAM, those same Scope 2 emissions carry an EU certificate cost that is currently seven to ten times larger than the CCTS cost per tonne. And the Renewable Consumption Obligation now requires captive power consumers to source 29.91% of electricity from renewables — scaling to 43.33% by FY2030. The economic case for the RE transition has been quietly transforming, driven not by environmental idealism but by the simultaneous convergence of three regulatory cost signals and a renewables cost curve that now puts solar open access in Odisha below Rs 5 per kWh.
India’s aluminium sector has installed approximately 9,500 MW of captive coal power to meet the continuous electricity demands of Hall-Héroult smelting. The all-in generation cost of captive coal power at a well-positioned plant — with captive coal blocks and mine-mouth access — is approximately Rs 5.0 to 5.5 per kWh, including capital charges, O&M, and coal procurement. Less advantageously positioned plants, dependent on market-linked coal procurement, operate at Rs 5.5 to 6.5 per kWh or higher. Solar open access in Odisha and Chhattisgarh — the states where the bulk of Indian primary aluminium is produced — now delivers a landed cost of approximately Rs 4.3 to 5.0 per kWh (Mercom Q2–Q3 2025 data). The pure electricity cost comparison is already marginal to slightly RE-favourable in the best states.
The CCTS GEI targets for aluminium smelters are plant-level and gazette-notified. Vedanta Jharsuguda Smelter II must reduce GEI from 13.49 to 12.83 tCO₂e/tonne aluminium by FY 2026-27; BALCO must go from 15.71 to 14.81; Hindalco Mahan from 15.63 to 14.74. A 25% renewable electricity substitution — replacing that share of coal CPP output with solar open access — reduces GEI by approximately 3.0 to 3.5 tCO₂/t aluminium, depending on the coal CPP’s emission factor. At expected CCTS CCC prices of Rs 900 to 1,150 per tCO₂e (analyst estimates for the aluminium sector), this translates to a CCC revenue or cost-avoidance of Rs 2,700 to 4,000 per tonne of aluminium — equivalent to approximately Rs 0.55 to 0.80 per kWh of renewable electricity consumed.
The CBAM Scope 2 dimension changes the calculation entirely for export-oriented producers. CBAM currently covers both Scope 1 and Scope 2 emissions for aluminium. Every kWh of coal CPP power replaced by renewable electricity saves approximately 0.8 to 0.95 tCO₂/MWh in Scope 2 embedded emissions. At the EU ETS price of approximately €80 per tCO₂e (equivalent to roughly Rs 7,200 per tCO₂e), each kWh of coal replaced by RE is worth approximately Rs 5.80 to Rs 6.90 in avoided CBAM certificate cost. This means the CBAM Scope 2 value of renewable substitution alone can exceed the full landed cost of the renewable electricity in Odisha — making the RE switch financially self-financing from the CBAM perspective before electricity cost savings or CCTS value are even considered.
The Renewable Consumption Obligation imposes a separate mandatory compliance pressure. An August 2025 government order requires captive power consumers to source 29.91% of electricity from renewables immediately, scaling to 43.33% by FY2030. Aluminium smelters with CPPs are captive power consumers. Non-compliance with RCO attracts RECs purchase obligations, and RECs — while satisfying the RCO — do not reduce CCTS Scope 2 intensity or CBAM embedded emissions. Procuring actual renewable electricity through open access or group captive structures simultaneously satisfies the RCO, reduces CCTS GEI, and reduces CBAM Scope 2 — three regulatory requirements discharged by one investment decision.
The “Big Four” Indian aluminium producers — Vedanta, Hindalco, NALCO, and BALCO — have collectively announced $5 billion in investments targeting 20 GW of renewable energy capacity by 2030. Vedanta currently sources approximately 5% of its electricity from renewables and targets 30% by 2030. NALCO targets 40% non-fossil power by 2030. Hindalco has signed a 1,335 MW long-term RE agreement for its Odisha and Chhattisgarh smelters and a 375–400 MW round-the-clock solar-plus-wind contract with Greenko. These commitments are large in scale but still lag the 43.33% RCO target and the CCTS GEI trajectory that will require even deeper carbon intensity cuts by 2028-30.
The captive coal CPP — why it exists and what it costs
Hall-Héroult aluminium smelting is not merely an electricity-intensive process — it is an electricity-continuous one. The electrolytic reduction cells that convert alumina to aluminium operate at temperatures of approximately 960°C, sustained by direct current electricity at high amperage. Any interruption to power supply — even for minutes — causes the molten bath to solidify, which can damage pot linings and force an expensive, weeks-long restart process. Aluminium smelters therefore require power that is not just cheap but utterly reliable, dispatchable at any time of day or night, and free from the voltage fluctuations that affect grid supply.
Captive coal power plants — built, owned and operated by the smelter company within or adjacent to the smelter site — have historically been the only viable solution to this reliability requirement in the Indian context. The grid in Odisha, Chhattisgarh, Madhya Pradesh and Uttar Pradesh, where the bulk of India’s aluminium production is concentrated, has historically been inadequate in reliability, frequency stability, and transmission capacity to support the continuous, baseload power demands of a large smelter without supplementary captive generation. The ~9,500 MW of captive coal capacity that India’s aluminium sector has installed is therefore not a preference — it is a technology response to a genuine infrastructure constraint.
The cost of generating electricity from an aluminium CPP depends heavily on coal procurement strategy. A smelter with captive coal blocks — such as Vedanta’s operations in Odisha, which have secured mine blocks in proximity to Jharsuguda — can produce coal-based electricity at approximately Rs 5.0 to 5.5 per kWh, including capital annualisation on a depreciated plant. A smelter dependent on market-linked coal procurement from Coal India Limited (with transport costs on top) faces effective generation costs of Rs 5.5 to 6.5 per kWh or higher, particularly after the coal price volatility of 2022-23.
At current costs, solar open access in the best aluminium states — Odisha and Chhattisgarh, which account for 82% of India’s primary aluminium production — is broadly cost-competitive with captive coal power for the variable cost portion of generation. It is not universally cheaper on a simple electricity cost comparison, particularly after ALCM-related module cost increases that added approximately Rs 0.25 per kWh to PPA tariffs in Q4 2025. But the electricity cost comparison alone is not the right analytical frame for an aluminium smelter in 2026. There are three additional value streams that the coal-to-RE switch generates that the pure electricity cost comparison ignores entirely.
The CCTS GEI value — what the compliance credit is worth per kWh
Under the CCTS, an aluminium smelter’s GHG Emission Intensity is calculated on a gate-to-gate basis that includes Scope 2 electricity emissions. Every unit of electricity physically sourced from a coal-based captive power plant contributes to Scope 2 GEI through the product of electricity consumed and the emission factor of the CPP. A typical Indian aluminium CPP operating at around 90% load factor on sub-critical technology produces approximately 0.85 to 0.95 tCO₂ per MWh of electricity generated. At the standard smelter electricity intensity of 14.5 MWh per tonne of aluminium, the Scope 2 contribution from coal CPP power alone is approximately 12.3 to 13.8 tCO₂e per tonne of aluminium — the dominant component of the GEI values reflected in the gazette-notified targets.
When a smelter replaces a portion of its coal CPP output with solar open access electricity — which carries zero GHG emissions at point of consumption — the Scope 2 GEI falls proportionally. A 25% renewable substitution across a 1 Mtpa smelter consuming 14.5 billion kWh per year replaces 3.625 billion kWh of coal power. At 0.9 tCO₂/MWh CPP emission factor, this avoids 3.26 million tCO₂e annually — a reduction of approximately 3.26 tCO₂e per tonne of aluminium produced. Against a CCTS target requiring, say, a 0.45 tCO₂/t reduction from the baseline to the FY 2026-27 target, a 25% RE switch does not merely meet the target — it generates a substantial surplus of CCCs that can be banked or sold.
At analyst estimates of Rs 950 to 1,150 per tCO₂e for the CCC price once aluminium smelters enter the market in volume, the CCC value of a 25% RE switch is approximately Rs 3,100 to 3,750 per tonne of aluminium. Expressed per kWh of renewable electricity substituted, this translates to approximately Rs 0.55 to 0.65 per kWh — a carbon compliance revenue that partially offsets the cost of the RE procurement itself.
The CBAM Scope 2 value — the number most CFOs have not yet put in their model
CBAM for aluminium covers both Scope 1 direct emissions from smelting and Scope 2 indirect electricity emissions. The inclusion of Scope 2 for aluminium — which is not the case for steel under the current CBAM framework — makes the electricity source the single most consequential variable in an aluminium producer’s CBAM cost calculation. And unlike CCTS, where the per-tonne CCC price is currently expected to be in the Rs 950 to 1,150 range in early market years, the CBAM Scope 2 cost is calculated at the EU ETS price — currently approximately €80 per tCO₂e, or approximately Rs 7,200 per tCO₂e at current exchange rates.
The table illustrates the arithmetic that most standard electricity cost comparisons miss. For an aluminium smelter exporting to the EU, the CBAM Scope 2 value of each kWh of coal power replaced by renewables is approximately Rs 6.48 — calculated as 0.90 tCO₂/MWh (typical coal CPP emission factor) multiplied by Rs 7,200/tCO₂e (CBAM equivalent). This single stream of value exceeds the landed cost of solar open access in Odisha. When electricity cost savings and CCTS compliance value are added, the total financial return from switching to RE is approximately Rs 7.88 per kWh of renewable electricity consumed — against a landed cost of Rs 4.30 to 5.00 per kWh.
Expressed differently: an aluminium smelter in Odisha that switches 25% of its CPP electricity to solar open access, and exports its aluminium to the EU, avoids approximately Rs 2,340 per tonne of aluminium in CBAM Scope 2 certificate costs at current EU ETS prices. Against a typical aluminium market price of approximately Rs 200,000 to 220,000 per tonne, this is a margin improvement of around 1.0 to 1.2% — meaningful in a commodity business where margins are measured in cents per kilogram. As EU ETS prices rise and the CBAM mechanism is extended, this value grows proportionally without any further action by the producer.
CBAM’s inclusion of Scope 2 for aluminium — while Scope 2 is currently excluded for steel — is the most consequential regulatory feature of CBAM for the Indian aluminium sector. The reason is structural: India’s aluminium GEI is dominated by Scope 2 electricity. A typical Indian smelter’s Scope 1 anode and process emissions are approximately 1.5 to 2.0 tCO₂/t aluminium. Scope 2 coal CPP emissions add approximately 12 to 14 tCO₂/t. So 85–90% of embedded emissions in Indian aluminium come from Scope 2 electricity. For a steel plant, Scope 2 electricity is typically a smaller proportion of total emissions, and CBAM currently only covers Scope 1 for steel, leaving the Scope 2 portion unpenalised. Aluminium exporters face the full Scope 2 penalty today. Every tonne of coal-based CPP electricity consumed is directly visible in the CBAM calculation — and every tonne replaced by renewable electricity directly and immediately reduces the CBAM certificate cost. The CBAM Scope 2 signal for Indian aluminium is therefore extraordinarily clear: the EU has, through the design of CBAM, made the electricity source of Indian aluminium a direct financial variable in export economics to one of the world’s largest premium aluminium markets.
The RCO pressure — what 43.33% renewable means for captive CPP operators
The Renewable Consumption Obligation, notified in August 2025, requires that captive power consumers source 29.91% of their total electricity consumption from renewable sources with immediate effect, rising to 43.33% by FY2029-30. Aluminium smelters operating captive coal CPPs are captive power consumers — the RCO applies to them directly.
The critical regulatory nuance — established clearly in previous Reclimatize analysis of the RCO-CCTS-CBAM interaction — is that compliance with the RCO through the purchase of Renewable Energy Certificates does not reduce the plant’s CCTS Scope 2 GEI or its CBAM embedded emissions. Only actual physical consumption of renewable electricity, delivered through green open access PPAs, group captive structures, or on-site renewable generation, simultaneously satisfies all three regulatory requirements. RECs satisfy the RCO at the lowest upfront cost but provide none of the CCTS or CBAM benefit. For an aluminium smelter, this distinction is worth Rs 7,000 to Rs 8,000 per MWh of renewable electricity consumed — the difference between REC-only compliance and actual RE procurement.
At a 43.33% RCO target by FY2030, a 1 Mtpa smelter consuming 14.5 billion kWh per year must source approximately 6.28 billion kWh from renewables annually. Against current solar open access PPA tariffs in Odisha of approximately Rs 3.0 to 3.3/kWh, this represents a total PPA commitment of approximately Rs 1,900 to 2,070 crore per year for this component of electricity procurement. This is not a small investment — but it is an investment that generates CCTS compliance value, CBAM certificate cost avoidance, and electricity cost savings simultaneously, all from the same contracted volume of renewable electricity.
The intermittency constraint — why round-the-clock RE matters so much for smelters
The single most legitimate operational objection to solar open access for aluminium smelters is intermittency. A solar PPA delivers power only during daylight hours — typically 6 to 8 hours of useful generation per day at high output, with partial generation in morning and evening. A smelter that draws 500 MW of power continuously cannot simply buy 500 MW of solar PPA capacity and shut the coal CPP down. The CPP must continue to run during non-solar hours, and the backup power requirement for smelting is absolute — there is no “demand response” mechanism that works for a continuous electrolytic process.
This is why the industry’s most sophisticated RE contracts are not simple solar PPAs but round-the-clock or near-round-the-clock renewable energy agreements that combine solar and wind in hybrid configurations, or add battery storage for evening hour coverage. Hindalco’s 375–400 MW agreement with Greenko specifically provides round-the-clock carbon-free power — meaning the contract guarantees supply at all hours, with Greenko managing the renewable portfolio mix (solar, wind, pumped hydro, storage) to deliver a continuous baseload equivalent. This is the commercial model that resolves the intermittency constraint for smelters: not solar-only, but hybrid renewable with storage, contracted on a 24/7 availability basis.
The cost premium for round-the-clock renewable power over a simple solar PPA is approximately Rs 0.50 to Rs 1.00 per kWh, reflecting the storage and firming cost embedded in the round-the-clock contract. At Rs 1,000 per MWh additional cost, the round-the-clock RE premium is still within the CBAM Scope 2 value of Rs 6,480 per MWh of coal power replaced — making the economics of firm renewable power procurement highly favourable even after accounting for the reliability premium.
For smelters that cannot yet access sufficient round-the-clock renewable capacity, the partial transition approach — replacing 30 to 40% of CPP power with solar open access during daylight hours, with the CPP continuing to cover nights and overcast periods — satisfies the near-term RCO obligation and generates meaningful CCTS and CBAM value while the round-the-clock infrastructure develops. This hybrid model is what NALCO, Vedanta and Hindalco are operationally doing today: incrementally displacing coal with solar during solar hours, progressively growing the renewable share toward the 2030 targets.
What the major players are doing — and what they still need to do
| Producer | Smelter capacity | CPP capacity | Current RE share | 2030 RE commitment | Gap to 43.33% RCO |
|---|---|---|---|---|---|
| Vedanta (Jharsuguda + BALCO) | 2.18 Mtpa | ~4,815 MW (Jharsuguda 3,615 + BALCO 1,200) | ~5% | 30% by 2030 ($15.42B greenfield CPP includes 4,900 MW new plant) | Large gap — 5% to 30% is 25pp below RCO 43% target |
| Hindalco (Renukoot, Mahan, Hirakud) | ~1.3 Mtpa India | ~2,300 MW across plants (Mahan 900 MW + Renukoot + Hirakud) | ~12–15% (growing) | 1,335 MW RE agreement for Odisha/CG smelters; 375–400 MW RTC with Greenko | Moderate gap — significant contracted pipeline; on track if deployed on schedule |
| NALCO (Angul) | ~460 Ktpa | 1,200 MW (Angul CPP) | ~10% (wind + small solar) | 40% non-fossil by 2030; 500 Ktpa brownfield expansion with RE blend | Moderate gap — government PSU with stated ambition; expansion includes RE from launch |
| Hindalco Aditya (Lapanga, Odisha) | 359 Ktpa (Mahan), separate at Aditya | Covered in Hindalco total | Early-stage; 25 MW solar at Mahan | Part of Hindalco group $5B commitment | Best positioned — Odisha location gives access to cheapest open access |
The industry-wide picture is one of genuine commitment at the announcement level and meaningful but insufficient progress at the implementation level. The “Big Four” have announced $5 billion in collective RE investments targeting 20 GW by 2030. Hindalco has the most concrete contracted pipeline. Vedanta is starting from the lowest base — 5% renewable share against a 30% target — and faces the biggest absolute gap to both its own 2030 commitment and the 43.33% RCO. NALCO, as a government undertaking, has the added governance dimension of public sector procurement procedures, which tend to move more slowly than private sector contracting.
CEEW analysis provides a useful external perspective: a 25% renewable electricity blend at the sector level results in a GEI reduction of approximately 3 tCO₂/t aluminium — enough to bring the best performers toward the gazette-notified year-two targets. The sector has an abatement potential at low or negative cost that significantly exceeds the first-phase CCTS requirements. The gap is not technology readiness or financial unviability — it is contracting pace, grid infrastructure buildout in Odisha and Chhattisgarh, and the partial intermittency constraint that limits how quickly pure solar can substitute for firm CPP power without RTC solutions.
Frequently Asked Questions
Why does CBAM cover Scope 2 for aluminium but not for steel?
The EU designed CBAM to capture the embedded emissions in imported goods based on the production process characteristics of each sector. For aluminium, the dominant emission source is electricity used in the Hall-Héroult electrolytic reduction process — typically representing 80–90% of total emissions. Excluding Scope 2 for aluminium would therefore exclude the majority of the sector’s actual carbon intensity from the CBAM calculation, making the mechanism ineffective for the stated purpose of ensuring a level playing field with EU producers who pay ETS prices on their electricity. For steel, Scope 1 process emissions from coke-based reduction dominate the intensity profile. Scope 2 has a smaller proportional role in steel, and the current CBAM framework has not yet extended to Scope 2 for steel — though this is expected in later implementation rounds as the mechanism matures.
Does buying RECs satisfy the RCO for aluminium smelters?
Yes — RECs satisfy the legal Renewable Purchase Obligation and the Renewable Consumption Obligation. However, RECs only satisfy the RCO and do not reduce the smelter’s CCTS Scope 2 GEI or its CBAM embedded emission calculation. Under the CCTS gate-to-gate methodology, Scope 2 is calculated based on actual grid electricity physically consumed at the plant multiplied by the grid emission factor — RECs purchased on the exchange do not reduce this calculation because the underlying physical electricity at the plant is still grid-sourced at the grid emission factor. CBAM similarly requires evidence of actual renewable electricity consumed at the point of production, not REC-based attribution. Aluminium smelters that use RECs to satisfy RCO are meeting the minimum legal requirement but forgoing the substantial CCTS compliance credit and CBAM cost avoidance that actual renewable electricity procurement generates.
Can a smelter run entirely on solar open access without backup coal power?
Not with solar-only procurement, given the continuous power requirements of Hall-Héroult smelting. Solar generation is typically available for 6–8 hours per day. During non-solar hours, the smelter needs an alternative power source. The options are: (1) maintain coal CPP for backup during non-solar hours, gradually reducing CPP utilisation as the RE share grows; (2) contract round-the-clock renewable energy — hybrid solar-wind-storage portfolios that deliver firm power at all hours — which Hindalco has done with Greenko; or (3) combination of solar PPA for daytime with contracted storage or pumped hydro for evening coverage. A full coal-free smelter requires either significant battery or pumped hydro storage capacity or a very well-designed hybrid renewable portfolio with geographic diversification across solar and wind resources. The CERC REC First Amendment (March 2026) introduced a 4× multiplier for offshore wind and 3× for pumped hydro — creating additional incentives for exactly the firming technologies that smelters need.
What GEI reduction can a smelter achieve by switching 30% of CPP power to renewable?
A 30% renewable substitution in a smelter consuming 14.5 MWh/t aluminium replaces approximately 4.35 MWh/t with zero-emission electricity. At a coal CPP emission factor of approximately 0.90 tCO₂/MWh, this avoids approximately 3.92 tCO₂/t aluminium in Scope 2 GEI. Against baseline GEI values in the Official Gazette — Vedanta Jharsuguda Smelter II at 13.49 tCO₂e/t — a 30% RE switch would alone reduce GEI by approximately 3.92 tCO₂/t, bringing the plant to approximately 9.57 tCO₂e/t. The notified FY 2026-27 target for this plant is 12.83 tCO₂e/t — meaning the RE switch would not just meet the target but generate a surplus of approximately 3.26 CCCs per tonne of aluminium produced, worth Rs 3,100 to 3,750 per tonne at expected CCC prices.