Industrial Solar Feasibility Study Checklist India: Seven Go/No-Go Tests

Proceed to tender only when seven tests have named evidence, an accountable reviewer and a go/no-go result: structure, usable area, interval load, transformer/feeder, interconnection, energy yield and financial sensitivity. A desktop quote is not a feasibility study.

Key Takeaways

• Treat feasibility as seven approval gates, not one optimistic generation estimate.
• Use 12 months of interval consumption data; monthly bills cannot reveal daytime export or demand interactions.
• Separate installed area from safe, maintainable, shadow-free usable area.
• Obtain structural and electrical sign-offs from competent professionals; an EPC salesperson’s assumption is not approval.
• Confirm the applicable state commission and DISCOM process before assigning value to export.
• Run downside cases for generation, tariff escalation, curtailment, downtime and capital cost.

What decision should the feasibility study produce?

Recommend go, go with conditions, or no-go/defer. Give each condition an owner, deadline and budget. Record sanctioned load, contract demand, meter category, operating calendar, roof ownership, commercial model and target commissioning date.

1. Is the roof and structure genuinely suitable?

Collect structural drawings, repair history, roof specification, purlin spacing, age, corrosion and leak evidence. Trace loads through attachments, purlins, frames and foundations. Include dead, wind, maintenance and concentrated loads. Do not infer capacity from another shed.

The Government of India’s DGT rooftop solar training material covers site survey, shading and mounting considerations, but project-specific structural acceptance remains an engineering task. Record fragile-roof controls, edge protection needs, fall-arrest anchorage and whether production fumes accelerate corrosion.

What is the roof gate checklist?

• Signed structural condition and capacity note with limitations.
• Attachment concept compatible with roof warranty and waterproofing.
• Wind design inputs and edge/corner zone treatment identified.
• Corrosion class, fastener material and isolation details specified.
• Repair or reroof timing compared with the solar asset term.

A “go with conditions” may require pull-out tests, member strengthening or reroofing. Price those before comparing solar bids.

2. How much area is actually usable?

Create a measured roof plan. Exclude skylights, vents, smoke hatches, drains, joints, weak zones, shadows and required access. Preserve equipment routes and model inter-row shading and future obstructions.

The result should show module tables, walkways, setbacks, inverter locations, cable routes and lifting/staging zones. Reconcile the layout with the factory sizing guide; nameplate capacity is an output of constraints, not the opening target.

What evidence prevents layout surprises?

Issue a georeferenced or dimensioned drawing, shade study, photographs, roof-zone register and a capacity range. Mark assumptions that need confirmation, such as an unmeasured parapet or planned exhaust stack. Require bidders to state whether their quoted capacity uses every exclusion shown.

3. Does interval demand absorb the solar profile?

Obtain 12 months of 15- or 30-minute import data, bills, shutdown calendar, shifts, seasonal production and planned load changes. Reconcile cleaned data to bills and overlay solar with demand.

Monthly units hide lunch dips, weekly closures and monsoon shutdowns. Calculate self-consumption, expected export, clipping, zero-export curtailment and demand-charge effects separately. If data are unavailable, install a temporary logger and label any early result provisional.

Which load cases should be tested?

Use normal operations, minimum stable load, weekly holiday, annual shutdown and announced expansion. For each, state imported energy, coincident solar, export/curtailment and peak demand. A project can remain viable with export, but only if the applicable mechanism, settlement and approval are confirmed.

4. Can the transformer, feeder and protection scheme accept the plant?

Update the SLD and verify transformer loading, bus and breaker ratings, cable ampacity, earthing, metering and relay settings. Study voltage rise, reverse power, faults, anti-islanding and coordination at the PCC. Certification does not replace a site study.

The CEA publishes the governing central framework under its Connectivity of Distributed Generation Resources regulations page. The applicable edition, state rules and utility requirements must be checked.

Who signs this gate?

A qualified electrical designer prepares the study; the plant’s authorised electrical personnel verify existing data; the DISCOM or inspector accepts only matters within its authority. Keep assumptions, calculations and proposed settings in the tender pack so all bidders price the same basis.

5. Is the interconnection route confirmed rather than assumed?

Identify the permitted metering or zero-export arrangement. Check eligibility, capacity limits, application, approval, agreement, meter, inspection and synchronization. State and DISCOM procedures vary.

For an example of utility workflow, MSEDCL’s rooftop solar standard operating procedure sets out application and commissioning steps in its territory; it is not a national template. Use the net-metering application guide to organize documents, then verify current local requirements directly.

What belongs in the approvals tracker?

List every submission, authority, prerequisite, fee, target date, response, validity period and owner. Do not put unconfirmed export revenue in the base case. Make bid responsibility explicit for drawings, tests, liaison, meter changes and resubmissions.

6. Is the energy-yield estimate auditable?

Require weather source, irradiation basis, equipment, orientation, shading, temperature model, DC/AC ratio and losses for soiling, mismatch, wiring, conversion, clipping, availability, degradation and curtailment. Compare P50 with a conservative case.

CEEW’s analysis of rooftop solar’s economic potential in India illustrates how consumer economics depend on tariffs and consumption profiles. It does not substitute for a site-specific forecast.

How should buyers challenge yield?

Ask an independent reviewer to reproduce key outputs and compare specific yield against credible local references. Require the bidder to distinguish model uncertainty from guaranteed performance terms. Weather variability is not contractor underperformance; availability and workmanship may be.

7. Does the project survive financial downside cases?

Build cash flows from verified load overlap and the approved settlement route. Separate self-consumed, exported and curtailed units. Include EPC price, strengthening, approvals, financing, insurance, O&M, replacement, degradation and downtime. Use the solar calculator, then retain the approval workbook.

Test at least lower generation, lower self-consumption, delayed commissioning, tariff stagnation, higher capex and combined downside. For procurement, compare inclusions through the EPC quote reading guide, not headline ₹/W alone.

What makes the final recommendation defensible?

Attach an assumptions register and sensitivity table. Finance owns hurdle and tax inputs; engineering owns technical inputs; operations owns load forecasts; legal owns property and contract risks. The steering committee accepts residual risks.

FAQ

How long should an industrial solar feasibility study take?

Timing depends on data quality, structural access, monitoring availability and utility response. A desktop screen may take days, but a decision-grade study should not be promised before surveys and essential electrical data are complete.

Can monthly electricity bills be enough?

They can support an initial screen, not a reliable self-consumption or export calculation. Interval data reveal daily minima, holidays and shutdowns that drive system size and savings.

Is a DISCOM feasibility approval the same as technical due diligence?

No. Utility approval addresses its process and network concerns. The buyer still owns roof integrity, internal electrical safety, constructability, energy yield and commercial diligence.

Should the study choose CAPEX or RESCO?

It should provide common technical facts and risk allocation inputs. The commercial choice depends on capital, credit, roof tenure, accounting and performance preferences; review CAPEX, OPEX and open-access options.

What if structural drawings are missing?

Treat capacity as unverified. Commission a measured survey and engineer-led investigation, with testing where justified. Do not let a visual inspection become an undocumented structural guarantee.

When is a no-go result useful?

Immediately—when it prevents sunk design, tender and mobilization costs. A no-go can also redirect the buyer to another procurement route while constraints are corrected.

Sources

• DGT rooftop solar training material
• MSEDCL rooftop solar standard operating procedure
• CEEW: Unlocking the Economic Potential of Rooftop Solar PV in India
• CEA connectivity of distributed generation resources