Hybrid solar + storage EPC, 1 to 10 MWp with 0.5 to 5 MW of storage

Solar and storage under one EMS. Near-zero DG hours, and a bus that does not drop.

Solar carries the day, the battery carries the evening peak and every outage, and the EMS decides moment to moment where the power comes from. The grid becomes one source among three, and the DG set becomes an insurance policy you rarely cash.

Get a free feasibility study How islanding works
4–6 yrstypical payback, indicative
Own worksswitchgear built and FAT-tested at Kotambi
Seamlessride-through on the critical bus
One EMSsolar, storage, DG and grid together
Energy flow in a hybrid plant: solar, battery, grid and DG feeding one WTS switchboard that supplies the plant WTS switchboard protection, islanding, EMS Solar carries the day Battery peak and outages Grid one source of three DG set rarely runs Your plant critical bus held surplus solar charges the battery
Four sources, one switchboard, one set of rules. The switchboard and the rules are what we make.

Why hybrid

Solar alone lowers the bill. Storage alone keeps you running. Together they do both, and each makes the other pay better.

  • Solar surplus is never wastedAt midday most plants cannot absorb all of a well-sized array. The battery takes the surplus and returns it at the evening peak, so you can size the array larger without depending on export rules.
  • The battery charges at the cheapest rate there isSolar at ₹2.5–3.5 a unit, not grid at ₹7.5 or diesel at ₹20. Every unit stored and used at peak is bought at the lowest price on the site.
  • Outages become invisible to the processWith solar and battery both behind a grid-forming PCS, the plant rides through a grid trip on its own generation. The DG starts only if the outage outlasts the stored energy.
  • Demand charges fall every monthThe EMS holds the import below a set kVA, using solar first and the battery second. The DISCOM bills the lower figure.
What each configuration delivers
OutcomeSolar onlyStorage onlyHybrid
Lower energy costYesPartlyYes
Lower demand chargesPartlyYesYes
Ride through a tripNoYesYes
Replace DG hoursNoMostNearly all
Use solar surplusExported or lostn/aStored
Typical payback3–4 yrs4–6 yrs4–6 yrs

On one line

How a hybrid plant is wired, and which parts are ours

Single-line diagram of a hybrid solar and storage plant showing which parts WTS manufactures Grid and DG set feed the WTS main switchboard. Solar inverters and plant loads connect to the main bus. A tie breaker links the main bus to a critical bus that carries the battery PCS and critical loads. The WTS EMS controls the inverters, PCS, tie breaker and DG. Orange elements are manufactured and tested by WTS. DISCOM grid 11 kV DG set 11 kV / 415 V sync breaker WTS main PCC, 415 V bus Solar inverters Plant loads tie / islanding breaker WTS critical bus Battery PCS Critical loads LFP racks WTS EMS control, metering and monitoring Manufactured and tested by WTS at Kotambi Procured from two approved vendors, back-to-back warranty EMS control and metering
What a hybrid plant looks like on one line. The orange parts are the ones that decide whether the plant actually holds the critical bus when the grid drops, and they are the parts we make.

Islanding

What happens in the second after the grid trips

This sequence is engineered, tested at commissioning in front of your team, and repeated at every annual service. It is why we build and test the switchboard, protection and EMS ourselves.

  1. Grid failsUnder-voltage and frequency relays on the incomer detect the loss within cycles
  2. Tie breaker opensThe critical bus separates from the grid; the anti-islanding scheme satisfies the DISCOM
  3. PCS forms the gridThe battery PCS sets voltage and frequency; critical loads see no interruption
  4. Solar rides alongInverters stay on, curtailed by the EMS so the island stays balanced; the DG starts only if needed
  5. ResynchroniseGrid returns, the EMS checks it is stable, the tie closes in sync, sources rebalance

Non-critical loads are shed at step 2 by the EMS according to a priority list you set. Most plants keep process, controls, lighting and safety systems on the critical bus and shed utilities.

Standard system

H-2000, a hybrid plant for a 1.5 to 5 MVA site

H-2000

2 MWp solar + 1 MW / 2 MWh storage

Rooftop or ground-mount array, containerised storage with grid-forming PCS, a WTS critical-bus switchboard and EMS. Sized for a plant that runs two or three shifts and cannot afford to stop.

Solar
2 MWp, ALMM modules, string inverters
Storage
1 MW / 2 MWh LFP, UL 9540A, NFPA 855 layout
Electrical
Critical-bus PCC, tie breaker, protection and EMS, built at Kotambi
Indicative price
₹10–12 Cr installed
Build time
Schedule given with the proposal, approvals running in parallel
Ask for an H-2000 study
Scope split

Who supplies what

The parts of the system that are commodities we buy from two approved vendors each, with warranties passed through. The parts that decide whether the plant works we make ourselves.

Bought in
Modules and structure, battery racks, inverters and PCS
Made by WTS
Critical-bus switchboard, protection, EMS, ACDB and DCDB, interface panels
Subcontracted
Civil works, structure erection, approvals filing
Tested at Kotambi
Every panel, before dispatch, with your engineer welcome to attend
Why that split matters

What we measure and report

Every number in your monthly report is read from the WTS EMS that we install, so there is never an argument about the data.

Witnessedislanding test at commissioning and at every annual service
Monthly reportmeasured savings against the feasibility study, every month under AMC

Any contractual guarantee is written into the proposal, never beyond what the OEMs guarantee to us. We do not promise what we cannot measure.

Questions we are asked about hybrid plants

Can I add storage to solar I already have?

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 old array under the new EMS. The array usually becomes more valuable than it was.

Does the DISCOM allow islanding?

Anti-islanding is mandatory and we build it in: when the grid fails the tie breaker opens and nothing is fed back. 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.

What does the DG do afterwards?

It stays as the last line of defence for long outages. The EMS starts it only when stored energy is running low and the grid has not returned, so it runs a fraction of its old hours and still gets exercised on schedule.

How much of my load can be critical?

All of it, if you size the storage for it. Most customers put process, controls and safety on the critical bus and shed utilities like HVAC and compressors, which cuts the battery size roughly in half.

See what a hybrid plant would do for your site

Twelve months of bills and a trip log are enough to size it. Three working days to the study.

Get a free feasibility study Analyse my bill first