Best Commercial Solar Proposal Software India: A Scored Comparison

Why This Matters for EPCs

Commercial solar proposal software turns a completed C&I design into a customer-ready proposal with yield, cost, payback and a deal-structure comparison. A C&I proposal can look finished and still stall after the customer has reviewed it. A facilities team checks the yield, a finance team checks the payback, and later someone checks the drawings against what gets built. Most commercial proposal tools were designed around US deal structures, so they are strongest on the first two reviews and thinnest on the third.

The Indian C&I market also does not run on one deal type. Rooftop projects sit behind the customer's meter, while open access and group captive projects supply power from an off-site plant. Each structure changes which documents the EPC has to produce, and a tool that only wins the proposal step leaves the rest of the paperwork to manual work at exactly the project sizes where mistakes cost the most.

1. Three Ways C&I Solar Gets Procured in India

Rooftop captive projects are the simplest. The system sits on the customer's own roof, is sold as CAPEX or as an OPEX/PPA arrangement, and connects through the DISCOM. Open access moves generation off-site. The customer buys power from a plant elsewhere on the grid, and projects wait on connectivity approvals, substation access and evacuation capacity.

Mercom India's Q4 and Annual 2025 report counts 7.8 GW of open access solar added in 2025, a record year but only 0.5% above the 7.7 GW of 2024. Cumulative open access capacity crossed 30 GW at the end of December 2025, and over 45 GW of projects were in development or pre-construction. The market is large. It is not accelerating on its own.

Group captive is the third route. Under Rule 3 of the Electricity Rules, 2005, captive users together must hold at least 26% of the plant's ownership and consume at least 51% of its generation. The Ministry of Power notified amendments to Rule 3 on March 13, 2026 that tie each user's captive consumption to its ownership share. The rule text matters here, so read the notified version before structuring a deal. For a deeper walkthrough of the open access entry process, see our step-by-step guide to a first C&I open access project.

2. What a C&I Proposal Has to Survive

A C&I buyer is rarely one person. The proposal passes through a facilities team that checks production, a finance team that checks payback, and later an engineer who checks the single line diagram against the installed system. Three things decide whether it clears all three without a redo.

First, a production estimate that holds up when someone questions it, not just a rendered rooftop. Second, equipment that was compliant when it was selected, so a swapped module or inverter does not surface a problem after the customer has the proposal. Third, a single line diagram in the format the approving authority accepts, generated from the same design instead of redrawn by hand.

Software built for another market can do the first well and miss the other two. That is the pattern the scorecard below is built to expose, and it is also why a bill of materials generated from the design matters at this scale. Our solar BOM automation guide shows how a 10 to 15% quantity error erodes project margin.

3. How We Scored Commercial Solar Proposal Software

Five criteria cover what a C&I EPC needs from proposal software. Two reward the strengths of US-built tools, and three reward India-specific fit. Weights reflect a typical Indian C&I EPC selling rooftop projects in the 50 kWp to 5 MWp range.

• Financial modeling and proposal output (25%): depth of yield, payback and deal-structure comparison in the customer-facing proposal.
• Simulation and lender credibility (15%): accuracy claims, P50 and P90 outputs, and acceptance in lender reviews.
• India C&I compliance (25%): real-time ALMM flagging and a DISCOM-format single line diagram from the same design.
• Mobile field design (15%): a usable design and proposal on a phone or tablet at the site.
• Automated BOM (20%): Bills of Electrical and Bills of Structure generated from the design, not rebuilt in Excel.

Each criterion is scored from 1 to 5 on documented capability. A 5 means the capability is native and documented, and a 1 means it is absent or depends on a separate tool. PVsyst is not scored because it is a complementary simulation tool, not a proposal platform.

4. The Scores

Every score has a stated basis:

• Reslink: CAPEX and OPEX/PPA proposals from one design, lender-grade P90 reports left to PVsyst, and mobile, BOM and India outputs native. Source: Reslink product documentation.
• HelioScope: the Pro plan lists financial modeling, sales proposals, P90 to P99 values and accuracy within 1% of PVsyst. It is browser-based with no dedicated mobile design workflow, needs a Unirac integration for Bills of Structure, and documents no India compliance outputs. Source: HelioScope pricing page and Reslink gap analysis.
• Aurora Solar: deep US utility-rate and financing integrations, but single line diagrams in US NEC format only, desktop-only, and no automated Bills of Electrical or Bills of Structure. Source: Reslink gap analysis, checked against vendor documentation.
• Arka360: professional CAPEX output with satellite design in India, but no OPEX proposals, no bank-ready DISCOM single line diagram, no automated BOM and desktop-only. Source: Reslink gap analysis, checked against vendor documentation.

The weights are a judgment, and a finance-heavy buyer would set them differently. Move 35% to financial modeling and 25% to simulation, with 15% for compliance, 10% for mobile and 15% for BOM, and the scores become Reslink 4.15, HelioScope 2.95, Aurora Solar 2.90 and Arka360 1.85. Reslink still leads, but the gap to HelioScope narrows from 2.05 points to 1.20. We show both sets so the result does not depend on one weighting.

5. Where Each Platform Fits

Reslink covers the full range an Indian C&I EPC sells. Reslink works exactly as seamlessly on desktop as it does on mobile, so the same satellite 3D design, equipment check and single line diagram run whether a salesperson is on a client's rooftop or back at the office. The CAPEX and OPEX proposal types share one design, so a deal that moves from a straight purchase to a PPA does not need a second tool. Its honest limit is lender-grade simulation, where PVsyst remains the standard for financed projects.

Aurora Solar is a strong US platform with a mature 3D engine, deep utility-rate integrations and professional proposal output. Those strengths do not carry into Indian approvals. Its single line diagram follows US NEC format, it has no mobile design workflow, and its OPEX tooling is built around US financing structures. Our Aurora Solar alternative guide covers where the gaps show up even inside the US.

Arka360 does satellite 3D design and CAPEX proposals within India, with a manageable learning curve. It does not generate bank-ready DISCOM drawings or an automated BOM, so those steps return to manual work. The full comparison sits in our Arka360 alternative guide, and the three-way view is in Reslink vs Aurora Solar vs Arka360.

PVsyst is complementary, not a competitor. For financed C&I and utility-scale projects that need a lender-grade P50 and P90 report, it handles the simulation stage. Reslink handles the design, proposal, BOM and drawings before and after it, and larger EPCs commonly run both. If you are still deciding whether you need design software, a CRM or both, start with our guide to solar software by type and use case. The full six-tool ranking and the nine-criterion scorecard give the wider picture.

6. HelioScope: Where the Design Caps Sit

HelioScope is the platform most directly aimed at C&I teams, and its simulation engine is a real strength. It is also an Aurora Solar product, not an independent tool. Its plans differ mainly by design size cap, which usually decides which plan an Indian C&I EPC can use. Basic costs $159 a month, caps designs at 1.25 MW DC and includes storage design and 10 projects a month. Pro costs $259 a month, caps designs at 5 MW DC and adds financial modeling, sales proposals, P90 to P99 values and LiDAR-assisted modeling. Enterprise is custom priced, caps designs at 30 MW DC and adds single-axis trackers, PVsyst export and API access.

A 2 MW rooftop therefore needs Pro. The caps are not the main limit for Indian EPCs, though. HelioScope has no documented DISCOM-format single line diagram, no dedicated mobile design workflow, and no native Bills of Structure without a third-party Unirac integration. A design can fit the plan and still leave the paperwork undone. Our HelioScope alternative guide goes deeper on PV and battery co-optimization from a phone.

7. What This Scorecard Does Not Measure

The scorecard rates design-and-document fit for Indian C&I work. It does not rate open access charge modeling, wheeling and banking calculations, or group captive equity structuring, and it does not test any vendor's claims there. It also does not score pricing, because plan prices change and Reslink's own pricing sits on the pricing page.

It is also written by Reslink, which has the same conflict of interest as any vendor-authored comparison. That is why every score above has a named basis and why the second weighting is shown. Check the basis column against each vendor's own documentation before relying on a number.

Common Mistakes to Avoid

Do not assume a tool built for commercial solar in another country is built for Indian commercial solar. A design cap of 5 MW says nothing about whether the drawings will be accepted by your utility. Do not treat open access and group captive projects like a standard rooftop sale, because the documents and approvals differ. Do not pick on a single weighting. A vendor's ranking should survive a second set of weights, and this one is shown against two.

How This Fits Into a Reslink Workflow

For an EPC mixing rooftop and off-site C&I work, Reslink's commercial solar proposal software starts every project the same way. A satellite 3D design captures the site, ALMM status is checked in real time as equipment is selected, and the same model produces the DISCOM-format single line diagram and the automated Bills of Electrical and Bills of Structure. A Nagpur-based commercial EPC closed a 500 kW project after presenting a 3D design with shadow analysis on-site.

See how a C&I proposal comes together end to end: Book a demo.

Frequently Asked Questions

Q1. What is commercial solar proposal software and how does it differ from residential tools?

It turns a completed C&I design into a customer-ready proposal with yield, cost, payback and a deal-structure comparison. The reviewers differ from residential: a facilities team questions the production figures, a finance team questions the payback, and an engineer later checks the drawings against the installed system. In India that adds equipment compliance, DISCOM-format drawings and a bill of materials generated from the same design.

Q2. What does Reslink generate from one C&I design?

From a single satellite 3D design, Reslink generates CAPEX and OPEX proposals, a DISCOM-format single line diagram, layout and string drawings, and automated Bills of Electrical and Bills of Structure. Equipment is checked for compliance as it is selected, so the drawings and material list match what the proposal quoted. When the design changes, the bill of materials updates with it, removing the manual rebuild that usually follows a revision.

Q3. Can Reslink produce CAPEX and OPEX proposals from the same design?

Yes. The CAPEX proposal covers generation, shadow output, payback and 25-year savings, and the OPEX or PPA proposal compares a tariff against the customer's DISCOM rate, both from the same design. Switching is a toggle, not a second workflow. That matters when a customer moves from buying the system to a PPA mid-negotiation. Aurora Solar's OPEX tooling is built around US financing structures, and Arka360 produces CAPEX proposals only.

Q4. Can Reslink handle a large C&I roof from a phone?

Yes. Satellite 3D design, shadow analysis and proposal generation run on a phone or tablet with the same capability as on desktop, so a salesperson can model a large roof or a multi-building campus while walking it with the customer. Drawings and the bill of materials come from the same model afterwards. Desktop stays useful for detailed review, but the workflow does not depend on returning to an office.

Q5. Does Reslink replace PVsyst for lender-financed C&I projects?

No. Lenders on larger financed projects commonly expect a PVsyst P50 and P90 yield report, and Reslink does not replace it. Reslink handles design, proposals, the bill of materials and drawings before and after the simulation stage, and larger EPCs commonly run both. Check your lender's technical requirements early, because the yield report is a separate deliverable that sits outside any proposal platform.

Q6. How does Reslink compare with HelioScope for a 2 MW commercial rooftop?

HelioScope needs its Pro plan at $259 a month for a 2 MW design, because Basic caps at 1.25 MW DC. Pro scores higher than Reslink on simulation in our scorecard. Reslink adds the Indian paperwork: a DISCOM-format single line diagram, automated Bills of Structure without a Unirac integration, and a mobile design workflow. The better fit depends on whether simulation depth or Indian documentation is your bottleneck.

Q7. Why did open access installations dip in late 2025?

There were two different causes. Mercom reported 2.2 GW added in Q3 2025, down 20% from Q2, because of grid connectivity delays, restricted substation access and limited evacuation capacity. Q4 fell further to 1.6 GW because many projects were commissioned early to beat the June expiry of the ISTS charge waiver. The full year still reached 7.8 GW, up 0.5% on 2024.

You May Also Like

• Best HelioScope Software Alternative in 2026
• Your First C&I Open Access Project: A Step-by-Step Entry Guide
• Solar BOM Automation: What It Actually Fixes

Sources

• Mercom India, Q4 and Annual 2025 India Solar Open Access Market Report summary (mercomindia.com): confirms 7.8 GW added in 2025, 0.5% above 2024, cumulative capacity above 30 GW, and over 45 GW in development and pre-construction.
• Mercom India, Q3 2025 India Solar Open Access Market Report (mercomindia.com): confirms 2.2 GW added in Q3 2025, down 20% quarter on quarter, with grid connectivity, substation and evacuation constraints.
• pv magazine India, India adds 7.8 GW of open access solar in 2025 (pv-magazine-india.com): confirms the Q4 2025 decline and the attribution to early commissioning ahead of the June ISTS waiver expiry.
• Powerline, Framework Reset: Revised rules for captive power plants, June 15, 2026 (powerline.net.in): describes the 26% ownership and 51% consumption test and the March 13, 2026 amendment to Rule 3. Single-source; confirm against the Ministry of Power's notified text.
• HelioScope pricing page and Help Center design-size article, accessed October 15, 2026: confirm plan prices, design caps of 1.25 MW, 5 MW and 30 MW DC, and the features listed per plan.