Open Access Power For EV Charging: Wheeling Charges, Duty And What A CPO Pays Per Unit

Open Access Power For EV Charging

Ask a charge point operator what a unit of electricity costs and you get the energy charge off the tariff schedule. That number is almost never what lands on the bill. Between the generator and the charger sits a stack of riders — wheeling charges, cross-subsidy surcharge, additional surcharge, standby charges, losses recovered in kind and state electricity duty — and on an open access transaction that stack routinely adds ₹2.50–₹3.00 to a ₹3.20 generation tariff. On 150,000 kWh a month, misreading it is a ₹35–40 lakh annual error in the business case.

This is for CPOs and fuel retailers with enough load across enough sites to have a procurement choice at all, and for real-estate and retail site owners billed as ordinary commercial consumers who do not know an alternative exists. It covers one half of the bill: the variable, per-unit half — where the electron is bought and what rides on it. The fixed, capacity half (contract demand, maximum-demand charges, peak shaving) belongs to our guide to EV demand charge management; tax on the onward sale to GST on EV charging; and getting connected at all to EV charging station licensing.

Three Ways A Charging Site Can Buy Power

There are only three, and most operators have only ever used the first.

Buy from the DISCOM on the EV tariff category. No minimum load, no contracts beyond the connection agreement. The Ministry of Power’s Guidelines for Installation and Operation of Electric Vehicle Charging Infrastructure-2024 require this tariff to be single-part and to stay at or below the state’s Average Cost of Supply until 31 March 2028 — 0.7× ACoS during solar hours (09:00–16:00), 1.3× outside them. For a single site that administered price is usually the right answer.

Buy from a generator and wheel it in under green open access. The Electricity (Promoting Renewable Energy Through Green Energy Open Access) Rules, 2022 cut the threshold from the Electricity Act’s 1 MW to 100 kW of contracted demand or sanctioned load, with no minimum at all for captive consumers; the 2023 amendment let a consumer aggregate multiple connections inside one distribution division to reach it. Applications are deemed approved if not decided in 15 days. For a public charging station the 2024 guidelines go further: open access within 15 days, a surcharge not exceeding 20% of the tariff applicable to that consumer category, plus transmission and wheeling charges — and “no additional fee will be applied beyond these.”

Own the generation — captive or group captive. Rule 3 of the Electricity Rules, 2005, substituted in full by the Electricity (Amendment) Rules, 2026 (G.S.R. 186(E), 13 March 2026), keeps the familiar test: captive users hold at least 26% of the ownership and consume at least 51% of annual generation. The 2026 substitution made group captive materially more bankable — ownership can be held through a holding company or its subsidiaries, and consumption routed through storage counts toward the threshold.

What Each Route Actually Lands At Per Unit

Below is one 1 MW, 150,000 kWh-per-month charging hub priced three ways on an MSEDCL HT connection, using the energy charges, wheeling charges and surcharge treatment MERC approved for FY 2025-26.

Tariff-order figures (energy charge, wheeling charge, surcharge treatment, demand-charge removal) are from MERC’s FY 2025-26 MSEDCL order and the Ministry of Power’s 2024 guidelines. Generation tariffs and loss/scheduling assumptions are illustrative and must be replaced with your own PPA and your own state’s open access regulations before this table is used for a decision.

Read the table as a gap, not as a price

The number that matters is the ₹2.06–2.26/kWh between the DISCOM EV tariff and green open access — about ₹3.1–3.4 lakh a month, ₹37–41 lakh a year, on 150,000 kWh. That gap, not the PPA price, is the prize, and it is what justifies the legal, scheduling and compliance overhead an open access arrangement carries; wheeling charges and losses are already inside it. Captive widens the gap to roughly ₹4/kWh, but demands 26% equity in a generating company: for a single 1 MW hub that means putting crores into an SPV to save lakhs, which is why captive is a portfolio decision and never a site decision.

Being in the wrong consumer category costs more than most riders

A site still billed as HT-Commercial in Maharashtra pays ₹8.83/kWh in energy charge against the EV category’s ₹7.64 — ₹1.19/kWh more before a single demand charge is counted, and HT-Commercial still carries a ₹560/kVA/month demand charge that the EV category no longer does. MERC’s reasoning is stated plainly in its order: it introduced a single-part tariff for the EV category and removed fixed and demand charges “in line with MoP Guidelines,” worth an 8–10% cut. Check which category your connection sits in before you model anything else.

Wheeling Charges And The Surcharge Stack, Rider By Rider

Wheeling charges and losses

Wheeling charges are rent for the distribution wires between the injection point and your meter. They are set per voltage level and fall as you go up: MSEDCL’s is ₹0.60/kWh at HT for FY 2025-26, ₹0.57 in FY 2026-27, and nil at EHV. Losses are separate and usually recovered in kind — you inject roughly 8–10% more than you draw, so a PPA quoted without the loss adjustment understates landed cost by about a third of a rupee.

Cross-subsidy surcharge — usually the biggest single rider

This compensates the DISCOM for the subsidy your category was funding before you left, so its size tracks how heavily cross-subsidising that category is: MERC has pulled HT-Commercial from 174% of Average Cost of Supply down to about 127% in FY 2025-26, and HT-Industry from 113% to 101%. Two caps matter — the green open access rules limit increases over a 12-year window to 50% of the surcharge fixed in the year access was granted, and the 2024 charging guidelines cap a public charging station’s surcharge at 20% of the applicable tariff outright.

Additional surcharge and standby charges

The additional surcharge recovers the DISCOM’s stranded fixed costs and is the most variable item in the stack: the rules exempt it where the consumer pays fixed charges, MERC has not allowed it on open access transactions at all this control period, and other states levy it in full. Standby charges apply only when you draw from the DISCOM because open access supply failed, capped at 10% of your category’s energy charge. Model both as scenarios, not constants.

Electricity duty

Electricity duty is the one line no regulator controls. It is a state tax, set by the state government rather than the commission, levied as a percentage of the energy bill, and it applies to open access and captive supply exactly as it does to DISCOM supply — so it survives every saving you engineer. The CEA’s annual Tariff and Duty of Electricity Supply in India collates the rates across states.

The EV Concessions That Change The Answer — And Why They Are State By State

There is no national EV power price — there is a national ceiling and a set of state decisions underneath it, and the spread between states is wider than the spread between routes inside one state.

The consequence for a multi-state operator: the same charger, the same utilisation and the same PPA produce different margins in different states, so a network-level tariff assumption is worthless — the same reason margins diverge across formats in our breakdown of EV charging station profit margin by site type. For EV charging for fuel retailers, where several forecourts in one state sit behind one energy contract, the state is the unit of analysis, not the site.

Banking, Scheduling And The Load-Profile Trap

This is where most CPO open access business cases quietly fail, and it has nothing to do with tariffs.

A solar open access contract generates roughly 08:00 to 17:00. A public hub’s demand peaks in the evening, a highway site at night, a bus depot almost entirely overnight. The curves barely overlap. Open access energy is scheduled — you nominate a quantum, the generator injects it, you consume it in the same time block. What you cannot consume goes to banking, and banking is where the state rules bite: the central rules contemplate monthly banking with intra-month adjustment and no carry-forward, while Maharashtra permits banked energy in every hour except the 17:00–24:00 evening peak, which is exactly when a public hub wants it.

Two things move that fraction. Generation mix: a wind-solar hybrid or a firm-and-dispatchable contract tracks an evening peak far better than plain solar, at a higher PPA price that usually still nets out ahead. And demand shaping: tariff design, smart-charging schedules and depot slotting can push a real share of kWh into solar hours, worth more than any surcharge negotiation. Both need session-level data by time block, per site, against the scheduled quantum — a reporting job for YoCharge’s charging management platform rather than a spreadsheet, because the nomination is monthly and the deviation penalties are not.

Which Route Makes Sense At Which Size

Below 100 kW, or a single site: the DISCOM EV tariff, no question — you are not eligible for green open access, and the administered tariff is already capped at Average Cost of Supply. Spend the effort on being in the right consumer category and shifting sessions into the 0.7× solar window.

100 kW to about 2 MW in one distribution division: green open access becomes arguable. Run the matched-fraction test before the tariff maths. If the evening peak dominates and banking is restricted in your state, the answer is usually no this year, yes once the portfolio grows or a hybrid PPA is available.

Above roughly 3–5 MW across a state, on a multi-year horizon: group captive starts to pay, because both surcharges disappear — wheeling charges and losses do not — and the 2026 amendment to Rule 3 has made the ownership structure far less fragile. It is an equity commitment that belongs in the capital plan, not the energy budget — see our EV charging station business plan guide.

If none of that clears: renewable energy certificates and the DISCOM’s green tariff are the light-touch alternative — a defensible green claim and RPO compliance with no scheduling obligation. Both cost more per unit than open access, not less: a green tariff is the retail tariff plus a premium. They are an answer for the sustainability report, not for the energy budget.

Frequently Asked Questions

Sources: Ministry of Power — Guidelines for Installation and Operation of Electric Vehicle Charging Infrastructure-2024 | MERC — MSEDCL Multi-Year Tariff Order, FY 2025-26 to FY 2029-30 | DERC — Tariff Orders | CEA — Tariff and Duty of Electricity Supply in India