The Real Cost of Open Access in India: Why the Exchange Price Is Never What You Pay
An HT Industry consumer in Maharashtra sees the Indian Energy Exchange Day-Ahead Market clear at an average of ₹4.10 per unit in FY 2024-25. Her DISCOM tariff, as approved by MERC in Case No. 226 of 2022, stands at ₹8.36 per kVAh. The arithmetic looks compelling — switch to open access, save ₹4 per unit, cut the electricity bill nearly in half.
That saving does not exist — not in that form. Between the IEX clearing price and what actually lands at a C&I facility's meter lies a stack of charges that, in some states and at some voltage levels, nearly eliminates the savings gap entirely. Understanding this stack is the difference between a sound energy procurement decision and an expensive miscalculation.
The Charge Stack: What Sits Between the Exchange Price and Your Meter
Open access, under Section 42 of the Electricity Act 2003, grants eligible consumers the right to procure power from sources other than their DISCOM using that DISCOM's network. The key word is 'using' — and using the network carries charges at every layer.
For a third-party open access consumer buying on IEX, the complete cost stack includes:
- The power cost — from IEX DAM, TAM, or RTM.
- Intra-state transmission charges — for use of the State Transmission Utility's (MSETCL) network.
- Wheeling charges — for use of the DISCOM's distribution network, plus wheeling losses applied in energy terms.
- Cross-Subsidy Surcharge (CSS) — compensates the DISCOM for revenue lost when a high-tariff C&I consumer exits its supply base.
- Additional Surcharge — compensates the DISCOM for stranded fixed costs of idle generation capacity; governed by Section 42(4) of the Electricity Act 2003.
- Scheduling and SLDC charges — for processing the open access transaction through the State Load Despatch Centre.
- Trader margin — if procured via a licensed trader; capped at ₹0.07/unit under CERC (Fixation of Trading Margin) Regulations, 2010.
Table 1: Indicative open access cost stack — HT Industry, Maharashtra, third-party IEX procurement, FY 2024-25. Sources: MERC Case 226/2022; MSEDCL Open Access Charges Circular; IEX FY 2024-25 DAM data; CERC Trading Margin Regulations 2010.
Charge Head | Approx. ₹/unit | Regulatory Basis
IEX / Exchange Purchase Price (DAM avg FY24-25) | ₹3.52–4.63 | IEX market data FY 2024-25
Intra-State Transmission Charges (MSETCL) | ₹0.50–0.70 | MERC / MSETCL Tariff Order
Wheeling Charges — MSEDCL (HT level) | ₹1.20–1.60 | MERC Case No. 226/2022
Cross-Subsidy Surcharge (CSS) | ₹1.69–2.30 | MERC Case No. 226/2022 — FY 2024-25
Additional Surcharge | ₹1.36 | MERC FY 2024-25 notification
Scheduling / SLDC Charges | ₹0.10–0.20 | MSLDC norms
Trader Margin (regulated cap) | ≤₹0.07 | CERC Trading Margin Regs 2010
Total Landed Cost (Indicative) | ~₹9–10/unit | Third-party OA, HT Industry, Maharashtra
Tariff note: The FY 2024-25 rates from MERC Case 226/2022 remain operationally applicable from April 2025 per MERC's interim order in Case 75/2025. Verify current rates at merc.gov.in before any commercial decision.
Key finding | The IEX DAM average — ₹3.52–4.63/unit across FY 2024-25 per IEX market data — is roughly 40–48% of the total landed cost for a third-party open access buyer in Maharashtra at HT voltage. Charges stacked on top nearly match the power cost itself.
Chart 1: Open access cost stack vs DISCOM tariff — Maharashtra HT Industry. Each bar segment represents one charge component. IEX price is the base; surcharges and wheeling stack above it.
CSS: The Charge That Most Often Derails an Open Access Business Case
The Cross-Subsidy Surcharge is the single most impactful and most frequently underestimated variable in India's open access economics. Under MERC Case 226/2022, CSS for HT Industry consumers in Maharashtra ranges from ₹1.69 to ₹2.30 per unit depending on feeder type. The National Electricity Policy envisaged CSS being progressively reduced toward zero as cross-subsidy is phased out; in practice, several states — including Maharashtra — have maintained elevated CSS as tariff reform has moved slowly.
Two structural exemptions materially change the calculus. First, captive and group captive consumers — who hold at least 26% equity in the generating entity per Rule 3 of the Electricity Rules 2005 — are exempt from CSS in most states. This is the primary driver behind the group captive model's superior economics versus third-party open access in high-CSS states. Second, under MSEDCL's September 2024 Green Energy Open Access notification, consumers procuring renewable power and paying fixed charges are exempt from the additional surcharge — a ₹1.36/unit saving in Maharashtra.
State by State: Where the Numbers Actually Work
The viability of open access for a C&I buyer is almost entirely determined by two state-specific variables: the DISCOM retail tariff (the saving opportunity) and the total open access charge burden (what erodes it). These vary enough to make a viable structure in Rajasthan unviable in Uttar Pradesh.
Chart 2: Indicative total OA landed cost across major industrial states — HT Industry, third-party open access, FY 2024-25. Source: Respective SERC orders. Figures indicative — verify with current SERC orders.
Rajasthan and Gujarat consistently offer the most favourable open access economics. Rajasthan's CSS rates are lower, and the state's green open access framework has additional incentives. Gujarat's captive structures effectively eliminate CSS for buyers who structure the required equity ownership. Maharashtra and Tamil Nadu sit in a moderate range — meaningful savings are available, but only through the right structure. Uttar Pradesh presents the most challenging environment for third-party buyers; captive or group captive is typically the only commercially viable route.
What Actually Saves Money: The Three Structures Worth Evaluating
1. Captive and Group Captive Open Access
By meeting the 26% equity and 51% self-consumption requirements under Rule 3 of the Electricity Rules 2005, C&I buyers eliminate CSS. In Maharashtra, this saves ₹1.69–2.30/unit — the difference between a marginal and a compelling business case. Mercom India reports that industrial buyers in Maharashtra can save ₹4.5–5 million per MW per year under solar captive structures, driven primarily by CSS exemption (Mercom India, August 2023).
2. Rooftop Solar — Outside the Open Access Framework
Rooftop solar under net metering bypasses the open access charge structure entirely. No CSS, no additional surcharge, no wheeling charges beyond MSEDCL's 8% banking charge. For facilities with adequate rooftop area, this remains the highest-return procurement option in most states, governed under state net metering regulations and CERC RE Tariff Regulations 2024.
3. Green Energy Open Access
MSEDCL's September 2024 Green Energy Open Access notification creates a meaningful exemption from the additional surcharge for renewable power consumers paying fixed charges. The IEX Green Day-Ahead Market cleared at an average of ₹3.43/unit in February 2026 per IEX data — below conventional DAM prices — making green open access worth modelling seriously for buyers who qualify.
How to Evaluate an Open Access Opportunity Correctly
A credible evaluation requires more than comparing IEX prices to the DISCOM tariff. The minimum inputs are:
- 12 months of DISCOM bills — to establish the true all-in cost per unit across all charge heads.
- Current-year CSS and additional surcharge rates from the applicable SERC order.
- Wheeling charges at the applicable voltage level — HT and EHV rates differ within the same state.
- Intra-state transmission charges from the State Transmission Utility's approved tariff.
- The specific structure — third-party, captive, or group captive — since applicable charges differ significantly.
- Consumption profile by time-of-day — IEX prices vary across 96 half-hour blocks daily.
Bottom line | In Maharashtra, total third-party open access landed cost approaches ₹9–10/unit — close to the DISCOM tariff, with limited incremental saving. CSS exemption through captive or group captive structures, or the additional surcharge exemption under green open access, is what changes the economics from marginal to material.
References
1. MERC Order Case No. 226/2022 — MSEDCL Tariff FY 2023-24 and FY 2024-25. merc.gov.in
2. MERC Order Case No. 75/2025 — Review of MSEDCL MYT Order; FY 2024-25 tariff extended operationally. mahadiscom.in
3. MSEDCL Open Access Charges Circular (April 2023) — CSS and additional surcharge rates. mahadiscom.in
4. Electricity Act 2003, Sections 42 and 42(4). indiacode.nic.in
5. Electricity Rules 2005, Rule 3 — Captive generating plant requirements. indiacode.nic.in
6. CERC (Fixation of Trading Margin) Regulations, 2010. cercind.gov.in
7. IEX Market Data FY 2024-25 — DAM price range ₹3.52–4.63/unit. iexindia.com
8. Power Line Magazine — 'Hitting Record Volumes: Power Trading Trends', October 2025. powerline.net.in
9. MSEDCL Green Energy Open Access Notification, September 2024. mahadiscom.in
10. Mercom India — 'High Tariffs in Maharashtra Drive Open Access Solar Adoption', August 2023. mercomindia.com
11. CERC RE Tariff Regulations, 2024. cercind.gov.in
All figures are indicative. Charge rates change annually with SERC orders. The Maharashtra HT tariff of ₹8.36/kVAh is the FY 2024-25 rate from MERC Case 226/2022, operationally extended per MERC Case 75/2025. Verify current rates before any commercial decision. This article is for informational purposes only and does not constitute regulatory or legal advice.
