You’re running a public charging network. You know your session volumes, your uptime %, your revenue per charger. But when your electricity bill arrives at the end of the month, does it get the same scrutiny?
For most CPOs, the answer is no. And that’s where the margin goes to die quietly.
Electricity is your single biggest operating cost. For a public HT-connected charging station in Delhi, that bill is built from at least ten distinct components – fixed charges, energy charges, PPAC, TOD surcharges, regulatory levies, pension funds, and tax. Most operators read the final number and stop there. The ones who read every line find the levers.
This is how to find them.
Before you start: four questions your electricity bill should answer every month
- Are you paying for capacity you never actually reach? (Contract Demand vs MDI)
- Are you charging vehicles during the hours that cost you the most? (TOD)
- Is your equipment quietly penalising you? (Power Factor)
- Are you in the right tariff category, or are you being billed under a legacy classification?
If you can’t answer all four from memory, your bill has information you aren’t using.
Section 1: Who you are to the DISCOM
Every letter in your bill is an identifier.Here’s what the most important ones mean:
CA Number is your permanent account ID. It doesn’t change. Use it for every interaction with the DISCOM, complaints, load revision requests, anything.
Bill Number is monthly. Think of it as an invoice number: it changes every cycle.
Energisation Date tells you when your connection went live. Relevant when auditing historical billing or disputing charge calculations that reference connection age.
Note: We’ve done this exercise for BSES bills but every discom has a slightly different variation of this.
Section 2: How your connection is classified
This section determines the rules of your billing.
Your connection type, LT or HT, depends on how much electricity you consume on the regular. Whether you’re a residential house or a commercial business owner like a charge point operator. This is basically your load size.
Small AC stations (3.3kW–22kW) typically run on Low Tension (LT) supply at 230/400V, comparable to a residential power supply.
Large fast-charging hubs and depot-scale installations are on High Tension (HT) supply at 33,000V, comparable to a commercial power supply.
The distinction matters because HT consumers face higher fixed charges but a lower per-unit energy rate, the grid rewards you for taking power in bulk, upstream of the distribution losses.
Your meter type will depend on your load size. 3PSK (Three Phase Static Meter) is standard for high-load HT stations. 1PSK (Single Phase) is fine for small AC chargers (3.3kW and below) on LT connections, but if you’re running a fast-charging hub or depot and see 1PSK, escalate. That’s an undersized meter for your installation.
The pole number on your bill identifies the feeder or transformer supplying your connection, it’s your address inside the electricity grid.
Section 3: The three numbers that determine your costs
This is where most ev businesses lose money.
a) Sanctioned Load The maximum electricity you’re authorised to draw. Set at installation. If your charging capacity has grown since then, your sanctioned load may be misaligned with your actual infrastructure.
b) Contract Demand (the critical one) The capacity you’ve booked from the grid, per month. You pay for this regardless of whether you use it.
Under Delhi’s DERC tariff structure, if you’ve contracted 500 kVA, you’re billed for 500 kVA every month, even if your actual peak was 300. This is not a penalty. It’s the price of the grid keeping that capacity reserved for you. Think of it as reserving 10 parking spots in a garage: you pay for the spots, not just the cars that showed up.
The question to ask every six months: does your Contract Demand reflect your actual peak usage? Revising it down saves real money. Leaving it too high is a monthly loss.
c) Maximum Demand Indicator (MDI) is your highest usage spike of the month, recorded in 15-minute intervals. If all five chargers are running simultaneously, say, a fleet returning together at end of shift, that peak moment of combined draw is what registers as your MDI.
MDI matters for two reasons: it’s used to calculate demand charges, and it’s your benchmark against Contract Demand. If your MDI is consistently 40% below your Contract Demand, you’ve over-contracted. If MDI routinely exceeds Contract Demand, you’re incurring a 30% surcharge on the excess, the DERC FY 2021-22 tariff schedule specifies this explicitly.
d) Power Factor is an efficiency score for your electrical system. 1.0 is perfect.
Think of it like a beer pour. The liquid is useful power (kW), what actually runs your chargers. The foam on top is reactive power, it takes up space in the glass and the grid has to carry it, but it does no useful work. A bad power factor means too much foam.
Below 0.9, your DISCOM charges you a penalty for the foam.
For charging stations, the mix of charger types affects how foamy your draw is. If your power factor is running low, the fix is an Automatic Power Factor Correction (APFC) panel, a one-time install at your main panel that essentially skims the foam. The DISCOM won’t do this for you; it’s your equipment, your fix.
Section 4: Your tariff category and what it actually costs per unit
Delhi Public EV charging stations are classified as HT EV consumers and billed at ₹4.00/kVAh, a concessional rate set to encourage charging infrastructure. (DERC Tariff Order, 2019)
Bengaluru KERC’s 2024 tariff order sets the EV charging rate under the dedicated LT-6(c) category at ₹4.50/kWh. (KERC Order, July 2024 via Mercom India) Note: KERC has proposed a roadmap to gradually reduce the EV charging cross-subsidy, currently at -48.83%, by 5% per year starting FY 2028-29. Rates will rise over time. (Energetica IndiaEnergetica India)
Mumbai Mumbai has no single rate, it depends on your DISCOM. MERC revised the EV charging tariff to ₹7.25/unit for all Mumbai licensees (Adani, Tata Power, BEST), with a ₹1.50/unit discount for charging between 10 pm and 6 am. (AutoEV Times, 2023) For MSEDCL (rest of Maharashtra), the EV charging station per-unit rate has been revised upward to ₹9.10 from ₹8.47 effective July 2025. AutoEVTimesFree Press Journal
This is cheaper than the general HT commercial rate, a deliberate policy choice to encourage public charging infrastructure. But the tariff only benefits you if you’re classified correctly. If your connection is still under a legacy non-domestic or industrial category, you may be paying the wrong rate. Check the tariff category on your bill against your connection type.
Time-of-Day (TOD) pricing: your most actionable lever
Delhi’s TOD structure applies to all consumers with sanctioned load ≥ 10 kW — which covers every public charging station.
- Peak hours (2–5 pm and 10 pm–1 am): +20% surcharge on energy charges
- Off-peak hours (4–10 am): −20% rebate
- Normal hours: ₹4.00/kVAh for HT EV consumers under DERC’s tariff framework
The single easiest way to reduce your electricity bill is to shift consumption out of peak hours.
Every unit charged between 4–10 am costs ₹3.20/kVAh. Every unit charged between 2–5 pm or 10 pm–1 am costs ₹4.80/kVAh. That’s a ₹1.60 swing per unit, purely based on timing.
CPOs have three practical levers to make this shift:
- Dynamic pricing on your app — charge users less during off-peak windows
- Off-peak discounts — flat incentive for early-morning sessions
- Scheduled fleet charging — for depot operators, programme buses to charge overnight or pre-dawn
The stations already doing this are seeing the difference directly on their bills. [Case study]
Section 5: How your actual consumption is calculated
Current Reading − Previous Reading = Units Consumed
But for HT connections, there’s a step before that.
Multiplication Factor (MF): Large commercial meters record at a compressed scale. The raw reading must be multiplied by the MF to get actual consumption. For HT depot connections, this factor can be 120,000, so a raw reading difference of 3 appears on your bill as 360,000 kVAh.
If you’ve been reading your raw meter numbers and wondering why the bill doesn’t match: the MF is why.
Your bill also shows two types of readings: Energy (kVAh), total electricity consumed, what you pay per unit for, and Demand (kW / MDI), peak load drawn at any single point, what you pay for capacity. You need to manage both. High session volumes with poor demand management will still produce a painful bill if your MDI keeps spiking.
Section 6: How the electricity bill is built, charge by charge
Net Payable = (A + B + C + D + E + F + G + H + I + J) − Rebate + Arrears + LPSC
A. Fixed Charges – Monthly charge based on Contract Demand. Payable even at zero consumption. This is the non-negotiable floor of your electricity cost.
B. Energy Charges – Units consumed × ₹4.00/kVAh (for HT EV consumers). If your billing cycle spans two calendar months, the DISCOM splits consumption by month for regulatory compliance.
C. PPAC on Energy – Covers the gap between what the DERC tariff assumed power would cost and what the DISCOM actually paid generators that quarter. It fluctuates monthly. (India.com, July 2024) You cannot control PPAC, but it explains why two months with identical consumption produce different bills.
D. TOD Charge — The ±20% adjustment on energy charges based on when your sessions occurred. This is the line that makes early-morning charging financially meaningful.
E. Regulatory Surcharge @8% — Applied on (Energy + Fixed − TOD Rebate). Funds recovery of the DISCOM’s accumulated regulatory assets. Set by DERC, not the DISCOM.
F. Pension Surcharge — Statutory levy funding pensions for retired employees of Delhi’s pre-privatisation state electricity board. Non-negotiable and applies to every consumer by law.
G. PPAC on Fixed Charge — Same PPAC logic as C, applied to your fixed charge component. C and G together are your total share of that month’s actual procurement cost.
H. Electricity Tax @5% — Goes directly to the state government. The DISCOM keeps none of it.
I & J. TCS and Other Charges — Mostly zero or negligible for standard charging operators. If non-zero, confirm it matches your contracted scale.
Below the main charges, check for: Provisional Bill Refunds (credit if a prior estimated bill overcharged you), Arrears (outstanding from prior cycles), and LPSC (Late Payment Surcharge if you missed a due date).
What to do with your electricity bill every month
There are 4 things that you need to be checking on every month.
1. Compare MDI to Contract Demand. Consistently 30%+ below? Apply for a downward revision. Routinely exceeding it? You’re paying a 30% surcharge on the excess, revise upward before the next cycle.
2. Check your TOD breakdown. Which hours drove peak charges? For managed or fleet charging, push sessions into the 4–10 am window.
3. Check your Power Factor. Below 0.9 means a monthly penalty. An APFC panel is a one-time capital cost that pays back through reduced charges.
4. Confirm your tariff category. You should be classified as an HT EV consumer at ₹4.00/kVAh. If your bill shows a general HT commercial or industrial classification, raise a reclassification request, retroactive credits apply if the error has been running.
Your electricity bill is not a document that gets handed to you without a 2nd look every month. Each line item is carefully and deliberately calculated, your business deserves the same scrutiny. Comment down below for more queries.
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