Selecting a solar EPC (Engineering, Procurement & Construction) partner isn’t just about finding the lowest price — it’s about ensuring quality, reliability, and long-term returns.
Every EPC company presents different designs, brands, and costs, which can make comparing proposals confusing.
A professional evaluation ensures your project is technically sound, financially viable, and future-ready.
Here’s a clear step-by-step guide from EKA Synergy Solar to help you evaluate solar EPC proposals and choose the right partner for your investment.
1. Understand the EPC Proposal Structure
A genuine EPC proposal should clearly mention:
- System capacity (kW or MW)
- Type of system: On-Grid, Off-Grid, or Hybrid
- Component specifications: Solar panels, inverters, structures, cables, and BOS (Balance of System)
- Scope of work: Design, installation, commissioning, and maintenance
- Financial summary: Cost per kW, subsidies, payback period, and ROI
If a proposal hides technical or financial details, that’s a red flag.
2. Compare the Quality of Components — Not Just Prices
The biggest price variations in EPC quotations often come from component selection.
| Component | Evaluation Criteria | What to Look For |
|---|---|---|
| Solar Modules | Tier & efficiency | Tier-1, MNRE-approved, 21–23% efficiency |
| Inverters | Type & brand | String/central inverter with MPPT technology |
| Structure | Material & coating | Hot-dip galvanized (80–100 micron) |
| Cables | Certification & type | IS-certified, UV-resistant solar cables |
| Protection | Safety & grounding | SPD, MCBs, proper earthing design |
Example:
Vendor A offers a Tier-1 540W mono-PERC panel with 21.4% efficiency. Vendor B quotes ₹10/W less for a 450W poly panel with 17.8% efficiency — but over 25 years, you may lose 12–15% in total energy output.
3. Evaluate Design Optimization and Performance Ratio (PR)
Every EPC company’s design approach affects your energy output and ROI.
Ask for the Performance Ratio (PR) — a key measure of system efficiency.
- PR above 78% is acceptable; 80–85% is ideal
- Ensure proper shadow analysis, cable sizing, and tilt optimization
Ask for simulation reports via PVSyst or Helioscope.
EKA Synergy Solar includes detailed loss diagrams, PR benchmarks, and location-specific simulations in every proposal.
4. Evaluate Payback Period, ROI & Total Cost of Ownership (TCO)
Price alone doesn’t define project value — returns do.
Compare proposals based on long-term value:
- ₹/kW installed
- Annual energy generation
- Payback period
- ROI percentage
- Subsidy + depreciation benefits
5. Review Scope of Work and Responsibility Division
Every EPC contract should define roles across key project phases:
| Phase | What to Verify |
|---|---|
| Design | Site analysis, structure layout, PR simulation |
| Procurement | Component brands, warranty documents |
| Installation | Skilled team, safety compliance, quality checks |
| Commissioning | Testing, grid tie-in, net metering |
| O&M Support | AMC terms, cleaning frequency, service SLAs |
6. Ensure Monitoring, Warranty & After-Sales Service
Post-installation service defines long-term project performance.
- Real-time app/web monitoring
- Performance guarantees (minimum output benchmarks)
Warranties: - Panels: 25 years
- Inverters: 5–10 years
- Workmanship: 1–2 years
- On-site issue response: within 48–72 hours
7. Scrutinize Certifications and Regulatory Compliance
Only work with EPC companies that provide:
- MNRE approval (for subsidy eligibility)
- ISO 9001 & 14001 certifications
- BIS/IEC electrical safety compliance
- DISCOM net metering registration support
8. Look Beyond Price — Evaluate Total Value
Beware of “cheap quotes” hiding exclusions like:
- Foundation costs
- Transportation
- Net-metering paperwork
- Cable tray, surge protection, or grounding
9. Ask for References & Site Visit Opportunities
Before finalizing, ask for:
- Past project performance data
- Client references
- Site visit options to operational plants
- Access to live generation dashboards
10. Red Flags to Watch For in EPC Quotes
Adding a final layer of protection:
- No PR or yield simulations
- Overly generic warranties with unclear issuer
- Unrealistically low costs with vague BOQ
- Delays in sharing past project performance
If in doubt — pause and verify.