Solar + BESS for Haryana Factories: 2026 Business Case

Direct Answer: Does Solar + BESS Pay for a Haryana Factory in 2026?

Not on Time-of-Day arbitrage alone in most cases. For a Faridabad factory taking DHBVN supply at 11 kV, the FY 2026-27 energy charge is ₹6.95/kVAh and the fixed charge is ₹290/kVA/month. Haryana’s current off-peak scheme offers ₹4.25/kVAh to eligible HT consumers, but only for qualifying incremental consumption, under an optional and seasonal arrangement. After battery round-trip losses, the theoretical energy spread is too small to justify a BESS by itself.

Solar + BESS becomes investable when it can stack two or more measurable benefits:

1. use otherwise stranded solar surplus;
2. reduce contract demand after an approved reduction;
3. displace audited diesel-generator runtime;
4. prevent costly production interruptions or quality losses; and
5. provide critical-load ride-through and power-quality support.

The correct decision requires 15-minute load data, 12 months of electricity bills, outage and DG logs, the current DHBVN ToD circular, and a vendor quote that includes degradation, augmentation, safety systems and financing. A battery sized as an arbitrary percentage of the solar plant is not a bankable design.

Tariff and regulatory status last checked: 10 July 2026.

The Haryana Reality: Five Facts Every BESS Model Must Use

HERC’s final tariff order also states that electricity duty, municipal or panchayat tax, and FSA/FPPAS sit outside the headline energy tariff. The facility’s actual bill is therefore the controlling source for a proposal.

For the underlying rules and application process, see our corrected DHBVN net-metering guide.

What Does the Current ToD Scheme Actually Offer?

Haryana’s FY 2026-27 tariff order continues an existing optional ToD/ToU arrangement. The historic design provides a concessional off-peak rate for incremental consumption above an approved baseline. It is not a simple tariff in which every night-time unit costs ₹4.25 and every evening unit attracts a standard peak premium.

The latest DHBVN implementation circular located during this review was for FY 2025-26. It applied:

• to eligible HT consumers who opted in;
• from November through March;
• to incremental consumption above the relevant baseline;
• during a prescribed night-time window; and
• only with a compatible meter and DISCOM approval.

The FY 2026-27 HERC order continued the scheme but allowed the DISCOMs to decide operating time slots and periods based on power availability and demand. HERC simultaneously found that the design had been ineffective and directed the DISCOMs to file a comprehensive replacement proposal.

Why a Generic “Peak ₹9.85 vs Off-Peak ₹7.50” Model Is Unsafe

That shortcut misses four questions:

1. Is the factory enrolled in the current scheme?
2. Is the charging load genuinely incremental above the accepted baseline?
3. Does the meter record the approved time blocks?
4. What does the latest DHBVN circular and the factory’s bill actually show?

If any answer is unknown, treat ToD savings as a sensitivity—not committed annual cash flow.

Worked Example: 500 kW / 1 MWh BESS at a Faridabad Factory

The example below is an illustrative screening model, not a Sun Wave quote or savings guarantee.

Reference Inputs

For a common reference case, we use assumptions published in the May 2026 IEEFA/JMK Research analysis of Indian standalone BESS tenders:

This benchmark comes from utility-scale tenders. A behind-the-meter industrial system may cost more because of smaller scale, switchgear, transformer work, controls, backup functionality, fire systems, civil works and integration with existing solar or DG equipment. Use an RFQ for an investment decision.

Value Lever 1: Grid-Charged ToD Arbitrage

If the factory qualifies for ₹4.25/kVAh off-peak energy and discharges the battery to avoid ₹6.95/kVAh normal energy:

• charging energy required per delivered unit at 90% round-trip efficiency = 1 / 0.90 = 1.111 units;
• charging cost per delivered unit = 1.111 × ₹4.25 = ₹4.72;
• gross spread per delivered unit = ₹6.95 − ₹4.72 = ₹2.23; and
• annual gross energy value = 237,600 × ₹2.23 = approximately ₹5.30 lakh.

That ₹5.30 lakh is before:

• annual O&M;
• cell degradation and augmentation;
• financing cost;
• auxiliary consumption and HVAC;
• downtime and availability;
• taxes; and
• loss of value when the battery is reserved for backup.

Conclusion: energy arbitrage alone is a weak base case at the verified Haryana tariff spread. It should not support a short-payback claim.

Value Lever 2: Recovering Stranded Solar Surplus

The strongest solar-plus-BESS case is not “store every solar unit.” It is “store solar that would otherwise have low value.”

Under Haryana’s 2025 second amendment, unadjusted net credits remaining at the end of the October–September settlement period are purchased at 90% of the applicable feed-in tariff. If the relevant feed-in tariff is ₹3.11/kWh, 90% equals approximately ₹2.80/kWh.

For a genuinely stranded unit:

• opportunity cost per delivered unit after 90% round-trip efficiency = ₹2.80 / 0.90 = approximately ₹3.11;
• avoided 11 kV grid energy = ₹6.95; and
• gross value spread = approximately ₹3.84 per delivered kWh.

At 237,600 kWh of annual delivery, the theoretical gross value is about ₹9.12 lakh per year.

This is an upper-bound screening result. If the exported solar credit would have offset future consumption within the settlement period, its opportunity value is closer to the retail energy charge and the battery adds little or no energy value after losses. The model therefore needs a full year of import/export and interval-load data.

Value Lever 3: Contract-Demand Reduction

HERC’s FY 2026-27 fixed charge for HT supply is ₹290/kVA/month of contract demand. A BESS can physically shave a short load peak, but the bill only falls if DHBVN approves a lower contract demand and the facility can operate within it consistently.

The calculation is straightforward:

Annual fixed-charge saving = approved contract-demand reduction × ₹290 × 12

Do not count this value from a single simulated demand spike. Confirm:

• the billing basis in the connection agreement;
• the process and cost to reduce contract demand;
• motor starting and seasonal production peaks;
• reserve margin after the battery degrades; and
• the penalty exposure if demand exceeds the revised limit.

Value Lever 4: Avoided Diesel Runtime

A battery can have a much higher avoided-cost spread when it displaces diesel rather than normal grid power.

Use the factory’s own fuel and maintenance records:

DG cost per kWh = litres consumed × delivered diesel price ÷ DG output + variable O&M

Then calculate:

Annual DG value = displaced DG kWh × (audited DG cost per kWh − battery charging opportunity cost per delivered kWh)

Important cautions:

• retain enough state of charge for the outage duty;
• do not double-count the same battery energy as both arbitrage and backup;
• separate planned load shedding from unexpected outages;
• include the value of any retained DG for long-duration events; and
• verify that the power-conversion system supports the required islanding or grid-forming mode.

For critical sites, a hybrid solar + BESS + retained DG architecture is often more resilient than removing the generator immediately.

Value Lever 5: Avoided Production Loss

For some factories, power continuity is worth more than electricity arbitrage.

Examples include:

• a furnace or heat-treatment batch that must be scrapped after interruption;
• a plastics line with long restart and purge losses;
• pharma HVAC or process controls that cannot tolerate a voltage sag;
• cold storage with temperature-compliance exposure;
• CNC, robotics or electronics lines with expensive unplanned resets; and
• data, automation or quality systems that require ride-through before DG starts.

Calculate this value from incident records—not a percentage added to the ROI:

Annual resilience value = avoided incidents × contribution-margin loss per incident + avoided scrap + avoided restart cost

If the plant has no recorded outage losses, resilience may still be operationally useful, but it is not a proven cash-flow line.

What Does the Combined Screening Case Look Like?

Using the 500 kW / 1 MWh reference system:

The energy values should not simply be added together; the same discharged unit cannot earn both grid-arbitrage and solar-surplus value. Build an hourly dispatch model that assigns each cycle to one use case and reserves the required state of charge for resilience.

When Solar + BESS Is Likely to Make Sense

A detailed feasibility study is warranted when at least two of these are true:

• the factory has repeatable solar export that remains unused by settlement;
• approved contract demand can be reduced materially;
• annual DG runtime and fuel cost are significant;
• short outages cause documented scrap, downtime or restart losses;
• loads continue after sunset and cannot be shifted operationally;
• the site has sensitive loads that need sub-second ride-through;
• grid import is constrained during production expansion; or
• the buyer values carbon, noise and local-emission reductions beyond direct payback.

When BESS Probably Does Not Make Sense Yet

Solar-only or battery-ready solar is usually the better first investment when:

• almost all solar generation is self-consumed directly;
• grid reliability is high and DG runtime is negligible;
• the plant cannot reduce contract demand;
• the current ToD concession is unavailable or too narrow;
• capital can fund additional direct-use solar with a higher return;
• no interval data is available to validate dispatch; or
• the proposal assumes battery prices will fall but does not contract the delivered cost.

In that case, install or expand rooftop solar under the verified Haryana regulatory framework, preserve space and switchgear capacity for future storage, and revisit BESS after the new ToD framework is published.

How to Size BESS Correctly

Battery power and energy solve different problems:

• kW or MW determines how much instantaneous load the battery can support or shave.
• kWh or MWh determines how long it can do so.

Step 1: Define the Primary Use Case

Choose one primary dispatch objective:

• demand limiting;
• solar-surplus shifting;
• DG displacement;
• outage ride-through;
• power-quality support; or
• ToD arbitrage.

Other objectives can be stacked only if their dispatch windows and state-of-charge requirements do not conflict.

Step 2: Size Power From the Load Curve

For demand limiting:

BESS power = observed peak demand − target grid demand + operating reserve

Use at least 12 months of 15-minute data. A monthly bill showing only the maximum value is not enough to reveal peak duration.

Step 3: Size Energy From Duration

Nameplate energy = load to be supported × duration ÷ usable depth of discharge ÷ discharge efficiency

For 400 kW of critical load, 90 minutes of support, 80% usable DoD and 95% discharge efficiency:

400 kW × 1.5 hours ÷ 0.80 ÷ 0.95 = approximately 789 kWh before adding degradation and reserve margins.

Step 4: Add End-of-Life and Availability Margins

Require the vendor to state:

• usable AC energy at commissioning;
• guaranteed usable AC energy at warranty end;
• annual degradation curve;
• permitted cycles and throughput;
• augmentation plan and cost;
• warranted availability; and
• auxiliary consumption.

A quote for “1 MWh” without the usable AC-delivered energy is not comparable.

Is BESS Mandatory for 1–2 MW Rooftop Solar in Haryana?

No current blanket requirement was found in HERC Regulation 54 of 2021 or its 2024 and 2025 amendments.

The frequently quoted rule—25% battery power with two-hour duration for incremental solar capacity above 1 MW and up to 2 MW—appeared in HERC’s 2019 rooftop-solar regulation. HERC’s regulations index records that 2019 framework as repealed by Regulation 54 of 2021. The current 2021 regulation instead caps ordinary net metering at 500 kW.

For any larger rooftop proposal, obtain a written response from DHBVN identifying the approved metering and interconnection route before treating storage as either mandatory or unnecessary.

BESS Safety: What Changes in 2027?

The Central Electricity Authority notified the CEA (Measures Relating to Safety and Electric Supply) Amendment Regulations, 2026 on 27 March 2026. They take effect on 1 April 2027.

For BESS connected above 650 V, the amendment introduces requirements covering:

• two-fault tolerance;
• cell, module, rack, container and site-level fire and explosion protection;
• BMS monitoring of voltage, temperature and thermal runaway;
• automated shutdown outside safe limits;
• explosion protection and forced ventilation for containers;
• separation from adjacent BESS enclosures and buildings;
• HVAC and flammable-gas control;
• smoke, gas, heat and flame detection;
• automatic fire suppression;
• fencing, CCTV and alarm systems;
• accessible manual emergency stops;
• earthing; and
• an independent third-party fire-safety audit submitted to the Electrical Inspector.

A system procured in 2026 will operate well beyond April 2027. Put these obligations into the EPC scope now rather than treating them as a future retrofit.

Procurement Checklist for a Bankable C&I BESS

Commercial Guarantees

• usable AC power and energy at the point of interconnection;
• end-of-warranty capacity and degradation curve;
• round-trip efficiency test method;
• annual and lifetime throughput warranty;
• availability guarantee and liquidated damages;
• augmentation/replacement responsibility;
• O&M scope, response time and spares;
• insurance requirements; and
• end-of-life recycling and disposal responsibility.

Technical and Safety Deliverables

• cell and pack traceability;
• BMS, PCS and EMS architecture;
• protection and coordination study;
• short-circuit, earthing and harmonics studies;
• hazard analysis and emergency-response plan;
• ventilation, gas detection and suppression design;
• fire-department and Electrical Inspector interface;
• FAT, SAT and performance-test protocols;
• cybersecurity and remote-access controls; and
• black-start, islanding or grid-forming capability if backup is promised.

Dispatch and Metering

• current DHBVN ToD eligibility and circular;
• interval meter-data integration;
• maximum-demand trigger logic;
• solar forecast and curtailment logic;
• reserved state of charge for outages;
• DG coordination; and
• a rule preventing double-counting of savings.

Data Sun Wave Needs for a Site-Specific Model

Provide:

1. twelve months of complete DHBVN bills;
2. sanctioned load and contract demand;
3. 15-minute or finer interval data for at least twelve months;
4. existing solar generation and export data;
5. production shifts, shutdowns and seasonal patterns;
6. DG size, fuel consumption, runtime and maintenance cost;
7. outage log with duration and affected load;
8. scrap, restart and lost-output cost per incident;
9. critical-load single-line diagram; and
10. roof, electrical-room and BESS-location drawings.

With those inputs, the model can separate direct solar value, storage value, resilience value and regulatory sensitivities instead of hiding them inside one optimistic payback number. For a high-level solar baseline, use our commercial and industrial solar guide and solar savings calculator.

Frequently Asked Questions

What is a realistic payback period for BESS at a Haryana factory?

There is no responsible single number. At verified tariffs, ToD arbitrage alone is usually weak. Payback improves when the same asset recovers stranded solar, supports an approved contract-demand reduction, displaces DG runtime or prevents documented production losses. Model each value stream from site data and include degradation, O&M, augmentation and financing.

Can a battery reduce DHBVN fixed charges?

Only if the facility obtains an approved lower contract demand and can stay within it. Physically shaving a short peak does not automatically change the ₹290/kVA/month billing basis.

What is the best BESS size for a 1 MW solar plant?

Solar capacity alone cannot determine battery size. Use the facility’s surplus-solar profile, target demand reduction, critical-load power, required backup duration and state-of-charge reserve. Two factories with the same 1 MW solar plant can need very different batteries—or no battery.

Is Haryana’s ₹4.25/kVAh off-peak tariff available all year?

Do not assume so. The previous DHBVN implementation was optional, seasonal and limited to qualifying incremental consumption. HERC continued the arrangement for FY 2026-27 while allowing DISCOMs to set periods and time slots. Confirm the latest DHBVN circular and bill.

Is solar-charged BESS always cheaper than grid-charged BESS?

Only when the solar energy has a low alternative value. If the solar would otherwise be self-consumed or offset later imports through net-metered credits, storing it adds round-trip losses. Solar charging is most valuable when it captures generation that would otherwise be curtailed or settled at a lower feed-in value.

Can BESS completely replace a diesel generator?

It can replace short-duration DG operation if power, energy, islanding and state-of-charge reserves are designed correctly. Long outages may still require retained DG or a much larger battery. Compare architectures against actual outage-duration data.

Which battery chemistry is best for an industrial system?

The procurement decision should compare tested safety, cycle/throughput warranty, temperature performance, supply-chain support and lifecycle cost—not chemistry labels alone. LFP is common in stationary systems, but the EPC still needs a compliant site design, BMS, ventilation, hazard detection and suppression.

Are the CEA’s 2026 BESS safety rules already in force?

They were notified in March 2026 and take effect on 1 April 2027. A 2026 procurement should nevertheless contract for the requirements because the asset will operate after the commencement date.

Do utility-scale tender prices equal a factory’s installed BESS cost?

No. Utility tenders benefit from scale and may have different land, evacuation, charging, VGF and contractual assumptions. The US$115/kWh benchmark used here is a reference input from IEEFA/JMK’s utility-scale viability analysis, not a turnkey quote for a Faridabad factory.

What should a CFO ask before approving BESS?

Ask for an hourly dispatch model, a no-double-counting value stack, usable AC energy at commissioning and warranty end, degradation and augmentation costs, current tariff eligibility, safety compliance, downside sensitivities, and references from comparable operating sites.

Primary Sources

• HERC final tariff order for FY 2026-27 — UHBVN copy, 25 March 2026
• UHBVN Sales Circular U-03/2026 — Schedule of Tariff for FY 2026-27
• DHBVN Sales Circular D-22/2025 — FY 2025-26 ToD/ToU implementation
• HERC Rooftop Solar Regulations, 2021 — DHBVN Sales Circular D-33/2021
• HERC Rooftop Solar Regulations — Second Amendment, 2025
• National Framework for Promoting Energy Storage Systems — Ministry of Power, official MNRE-hosted copy
• Viability of Standalone Battery Energy Storage Tariffs Discovered in 2025 — IEEFA and JMK Research, May 2026
• CEA Gazette Notifications

This article is an educational screening framework, not a tariff opinion, engineering design or savings guarantee. Obtain a current DHBVN bill and circular, written interconnection confirmation, a detailed load study, and professional electrical/fire-safety advice before procurement.