Solar + BESS EPC — Frequently Asked Questions

Indicatively ₹60–75 lakh a year per MWp, net of the solar plant's own levelised cost, for an HT consumer paying ₹7.5–8.5 a unit. A 1 MWp plant in Gujarat generates roughly 1.4 million units a year; every unit consumed on site avoids the grid rate. The feasibility study replaces this range with your own tariff and load.

Indicatively 3–4 years for solar alone on a self-consumption basis, 4–6 years for storage used for peak shaving and DG replacement, and 4–6 years for a hybrid plant that does both. All three depend on your tariff, load shape, DG hours and demand charges, which is why we start with a feasibility study.

Residential rooftop schemes such as PM Surya Ghar do not apply to industrial consumers. The benefit that usually does apply is accelerated depreciation on the asset under the Income Tax Act, which shortens the effective payback; confirm it for your company with your tax adviser. We model the payback without any subsidy so the case stands on its own.

No. We design for self-consumption: the plant is sized so that nearly all of its output is used on site. Current GERC regulations favour self-consumption over export, and export and banking rules change. Where export is permitted we build in the metering, but we never base your payback on it.

The DISCOM bills you for the highest kVA you drew in any 15 or 30-minute window of the month, on top of the units you used. Storage discharges during that peak so the recorded maximum is lower, and the demand charge falls every month whether or not the grid ever trips. On many industrial bills demand charges are a fifth to a quarter of the total.

Yes. Where your tariff has peak and off-peak slabs the battery charges in the cheap window and discharges in the expensive one. On its own this rarely justifies a battery, but combined with demand-charge reduction and DG replacement it adds a useful margin.

Yes. We can introduce you to financing partners who own the asset and sell you the power, or to lenders who finance the plant on your books. We design, build and maintain the plant either way; the ownership structure is your choice.

Lithium iron phosphate, LFP, only. We do not install NMC chemistry in industrial sites. LFP tolerates heat better, is far less prone to thermal runaway, and carries the rack manufacturer's warranty, passed through to you back-to-back in writing.

LFP racks carry the manufacturer's warranty in years or cycles, with a capacity floor, passed through to you back-to-back in writing. The EMS is tuned to keep the system inside its cycle budget.

A power conversion system that can set voltage and frequency itself rather than following the grid. It is what lets the battery hold your critical bus when the grid drops, synchronise with a DG set and share load with it. A grid-following inverter cannot do any of that; it simply switches off when the grid does.

Anti-islanding is mandatory: when the grid fails, the tie breaker opens so that nothing is fed back into the DISCOM network, and we build that in. Intentional islanding of your own critical bus behind that breaker is your plant, and the scheme is submitted to the DISCOM with the interconnection application. The sequence is tested at commissioning in front of your team.

Yes, and it is one of the best cases. We check the existing inverters and switchboard, add the PCS and a critical-bus panel, and bring the existing array under the new EMS so its surplus charges the battery. The array usually becomes more valuable than it was.

All of it, if you size the storage for it. Most customers keep process, controls, lighting and safety systems on the critical bus and let the EMS shed utilities such as HVAC and compressors during an outage, which roughly halves the battery size.

Yes. The PCS synchronises with the DG so the two share load, and the EMS decides when the DG starts. In most plants the DG runs a fraction of the hours it did before and still gets exercised on schedule.

The energy management system decides, moment to moment, where your power comes from: it holds grid import below a set kVA, charges the battery from solar surplus, sheds and restores loads during an outage, manages state of charge, synchronises sources and records everything. It is manufactured and programmed by WTS and it is what the monthly performance report is read from.

Chemistry first, LFP only. Then certified racks tested to UL 9540A for thermal runaway and IEC 62619 at cell and module level. Then layout to NFPA 855 clearances with ventilation, detection and suppression designed in. Then a review of the layout and suppression with your insurer before installation, not after. No single measure is relied on.

Low-voltage switchboards are built on Rittal Ri4Power, Siemens SIEPAN or C&S CX systems and verified to IEC 61439-1 and -2 by design verification. Every board passes a factory acceptance test at Kotambi before dispatch and the report is in your file.

Not legally, but we treat it as if they do. We share the layout, chemistry certificates and suppression design with your insurer at the design stage and incorporate their requirements. It avoids a premium surprise later and it is good engineering discipline.

Our own electrical crew works under a permit-to-work system with a daily safety brief. Tie-ins to your main bus are scheduled for a shutdown window you agree, usually a few hours, and everything else is built and tested beside the plant before that window.

Battery racks, PCS, modules and inverters carry their manufacturers' warranties, passed through to you back-to-back in writing. WTS switchboards, protection and EMS carry our workmanship warranty, with OEM terms on relays and metering; the exact terms are written into the proposal. We do not promise beyond what the OEM promises us.

Across Gujarat's industrial belt within about 250 km of our works at Kotambi, Vadodara, which covers Savli, Halol, Waghodia, Jhagadia, Dahej, Ankleshwar, Panoli, Vapi, Sanand, Rajkot, Morbi and Jamnagar among others. We are extending to Maharashtra and Rajasthan for larger projects.

A DISCOM application for captive or net-metering interconnection with the single-line diagram and protection scheme, DISCOM technical feasibility, a CEIG inspection of the installation, and synchronisation with the DISCOM meter. GEDA registration applies in some cases. We file and follow all of them in parallel with engineering.

About one acre of roof per MWp for rooftop, or about four acres of land per MWp for ground-mount, depending on orientation and shading. For storage, a 1 MW / 2 MWh containerised system needs roughly the footprint of a 20-foot container plus clearances, PCS and the switchboard.

We check before anything else. Most pre-engineered steel sheds carry the load without strengthening; some older RCC roofs need a ballast or elevated structure. If the roof cannot take it we say so and look at ground-mount or a carport structure.

It depends on size, site and approvals. You get a stage-by-stage schedule with the proposal, with approvals running in parallel to engineering and manufacturing. Approval timelines vary by DISCOM circle.

Because the part of the plant that decides whether it works during a power cut is the electrical system: switchboard, protection, islanding, EMS. We have manufactured and tested that at our own works for years. We keep it in our own hands. We make it, test it, commission it and maintain it with the same team.

Yes, and we would like you to. The Kotambi works is on the Halol–Vadodara road and you are welcome to attend the factory acceptance test of your own panels before they ship.

Yes. ACDB, DCDB, PCC and BESS PCC, busduct, container electrical fit-out and EMS panels, built and tested at Kotambi and shipped ready to install. See the electrical balance of plant page for the range.

Send twelve months of HT electricity bills and, if you have one, a DG log. We return a six-page feasibility study in three working days with your real cost per unit, a sized system, the payback and an indicative single-line diagram. No obligation.