Your Electricity Bill Is a Roadmap — If You Know How to Read It

The headline tariff is not your cost. Your DISCOM bill contains the full story of what you pay — and inside it are the exact signals that tell you whether DISCOM supply, open access, or rooftop solar is right for your facility.

Ask any energy manager at a C&I facility what they pay for electricity and they will quote a number. Ask them how that number is built — and most will pause.

That pause is expensive. For HT (High Tension) C&I consumers connected at 11 kV and above, the headline energy tariff is typically less than half of the actual blended cost per unit once every charge, duty, and surcharge is included. The remainder is a structured stack of costs — some fixed, some variable, some avoidable — that most energy managers have rarely seen decoded line by line.

This guide walks through your bill in three linked parts: what you pay on DISCOM supply, what changes when you move to open access, and what rooftop solar and BESS do to the picture. Each part references actual Maharashtra HT bills for illustration. The charges across all three parts are connected — the savings opportunity only becomes visible once you see the full map.

PART 01 WHAT YOU PAY ON DISCOM SUPPLY

Your DISCOM bill has two layers — most businesses only read the first

Under the Electricity Act, 2003 and the regulations issued by each State Electricity Regulatory Commission (SERC), an HT industrial bill is structured in two broad layers. The first is tariff-based charges — energy charge, demand charge, and fixed charge — set by the SERC in its annual Tariff Order. The second is statutory add-ons — Fuel Adjustment Charge, Electricity Duty, and Time-of-Day adjustments — layered on top and often not well understood. The second layer is where most of the variability and most of the cost-reduction opportunity sits.

In Maharashtra, the MERC Review Order (Case No. 75 of 2025), issued on 25 June 2025, confirmed revised tariffs effective 1 July 2025. These build on the MYT Order (Case No. 217 of 2024). The tariff structure in the bills below reflects rates applicable from July 2025 onwards.

Figure 1: Illustrative sample bill showing Standard MSEDCL HT Bill (FEB-2026) · Demand Charges, Energy Charges, TOD Tariff EC, FAC and Electricity Duty as separate line items

A critical detail on demand charges: the metering period in Maharashtra is a 30-minute sliding window (as confirmed in the MERC MYT Order, Case No. 217 of 2024), not 15 minutes as in some other states. This means even a half-hour peak event sets your demand for the entire month. A single machine startup, compressor cycle, or furnace ramp that briefly spikes demand above your normal level drives your demand charge for 30 days. Reviewing your maximum demand records each billing cycle against your contracted demand — and applying to reduce contracted demand if consistently underutilised — is the single fastest administrative action to reduce the bill.

PART 02 WHAT CHANGES WHEN YOU MOVE TO OPEN ACCESS

Open access doesn't eliminate your bill — it changes what's on it

When a facility takes open access — procuring power from a third-party generator or exchange such as IEX rather than buying 100% from the DISCOM — the bill splits into two sections: MSEDCL consumption charges (in this bill’s case) for units still drawn from the grid, and open access charges for using the distribution and transmission network to wheel third-party power. New charge lines appear that DISCOM-only consumers never see.

The Electricity (Amendment) Rules, 2022 (Ministry of Power, notified 29 December 2022) introduced a significant reform: the Cross-Subsidy Surcharge (CSS) must now be kept within ±20% of the Average Cost of Supply (ACoS). This has directly reduced the open access charge stack in Maharashtra. The Electricity (Promoting Renewable Energy Through Green Energy Open Access) Rules, 2022 also reduced the eligibility threshold for open access from 1 MW to 100 kW, expanding the addressable market significantly.

Figure 2: Illustrative sample bill showing Open Access Section — MSEDCL HT Bill (FEB-2026) · Wheeling Charges ₹4,49,947 · Transmission Charges ₹6,93,162 · CSS and Additional Surcharge lines visible

GROUP CAPTIVE EXEMPTION — THE MOST IMPORTANT PLANNING INSIGHT

Both CSS and additional surcharge are exempt for consumers sourcing power through a Group Captive arrangement — where the consumer holds at least 26% equity in the generating entity and draws at least 51% of contracted requirement from it. This exemption under Section 9 of the Electricity Act, 2003 makes group captive structures significantly more cost-competitive than third-party open access for facilities above 3–5 MW. The OA charge stack in Figure 2 — ₹13.44 lakh/month — would be materially lower under group captive.

PART 03 WHAT ROOFTOP SOLAR AND BESS DO TO THE PICTURE

Solar and BESS don't replace your bill — they restructure it

Rooftop solar and battery storage do not make your electricity bill disappear. They change its structure — reducing the energy charge component while leaving demand charges, FAC, and Electricity Duty on the remaining DISCOM units. Understanding precisely which charges solar addresses and which it does not is what determines whether the economics are viable for your facility.

Figure 3: Illustrative sample bill showing TOD Tariff EC and FAC Lines — MSEDCL HT Bill (FEB-2026) · TOD Tariff EC credit of −₹11,229 and FAC debit of ₹7,471 as the two variable charge lines solar most directly addresses

The TOD Tariff EC line in Figure 3 shows a credit of −₹11,229. This facility is already drawing significant consumption during solar hours (09:00–17:00), earning the rebate. Rooftop solar offsets DISCOM units consumed during exactly these hours — when the MERC MYT Order FY 2025-26 provides a −15% rebate (summer) or −25% rebate (winter). This is the overlap where rooftop solar deliver additional financial returns per unit generated: avoiding consumption at the TOD-rebated rate means the effective cost of avoided DISCOM power is lower than the headline tariff.

The FAC line — ₹7,471 at 40 paise/unit in this bill — is also directly addressed by solar. Every unit generated on-site is a unit that does not attract the FAC surcharge. Since FAC is variable and SERC-approved monthly or quarterly, on-site solar generation provides a natural hedge: your solar cost is fixed while DISCOM FAC fluctuates. This is one of the structural arguments for rooftop solar referenced in the CERC Terms and Conditions of Tariff Regulations, 2024 context of long-term fixed-tariff procurement.

What solar does not address: the demand charge. Your contracted demand charge of ₹600/kVA is payable regardless of how much solar you generate — because it is set by the peak 30-minute demand window, not by average consumption. A 500 kW rooftop system on a facility with a contracted demand of 3,000 kVA still pays the full demand charge. This is precisely why BESS pairs with solar: BESS discharges during evening peak hours (17:00–24:00) to flatten the demand spike and reduce maximum demand, while solar covers daytime energy substitution. The MERC MYT Order FY 2025-26 ToD structure — with the largest spreads between peak surcharge (+25%) and solar rebate (−15% to −25%) — is the regulatory framework that makes this BESS arbitrage viable.

India's national AT&C losses declined to 15.04% in FY 2024-25 (from 15.97% in FY24), according to the Ministry of Power's 14th Integrated Rating and Ranking Report, 2025. Maharashtra's MSEDCL recorded AT&C losses of 17.69% in FY25 — above the national average. These losses are embedded in your tariff: every unit of DISCOM power you substitute with on-site solar reduces your indirect contribution to this cost. On-site generation is not subject to distribution losses.

From bill to decision

Your bill is a map — not just an invoice

The energy charge tells you how much of your cost is unit-based — amenable to open access or rooftop solar substitution. The demand charge tells you how much is peak-driven — amenable to BESS or load scheduling. The FAC tells you how much is fuel-cost pass-through — the cost of staying exposed to DISCOM supply risk.

The question is not "is open access or solar worth considering?" The question is: "by exactly how many rupees per unit does each option undercut what I am currently paying, on which specific charge line, over what payback period, and under which regulatory structure?" That is a calculation with a precise answer. It starts with three numbers from your bill: your true all-in blended cost per unit, your demand charge as a share of total bill, and your FAC run-rate over the past six months.

Sources & references

All sources are primary government and regulatory documents. Click any link to access the original document.

→ Electricity Act, 2003 — Sections 9, 42, 45, 61, 62, 64 · cercind.gov.in

→ Ministry of Power — Electricity (Amendment) Rules, 2022 (CSS cap ±20% ACoS), notified 29 December 2022 · powermin.gov.in

→ Ministry of Power — Electricity (Promoting Renewable Energy Through Green Energy Open Access) Rules, 2022 · powermin.gov.in

→ Ministry of Power — Smart Meter National Programme; ToD tariff guidelines · powermin.gov.in

→ Ministry of Power — Annual Reports · powermin.gov.in

→ Ministry of Power — 14th Integrated Rating Report FY 2024-25: AT&C losses 15.04% (Mercom India summary) · mercomindia.com

→ CERC — Terms and Conditions of Tariff Regulations, 2024 · cercind.gov.in

→ CERC — Deviation Settlement Mechanism and Related Matters Regulations, 2024 (amended 2025) · cercind.gov.in

→ DERC — Terms and Conditions for Open Access (Second Amendment) Regulations, 2026 (additional surcharge 4-year phase-down) · derc.gov.in

→ MERC — MYT Order Case No. 217 of 2024: MSEDCL Tariff FY 2025-26 to FY 2029-30 (28 March 2025) · mahadiscom.in