Industrial solar case study India: 120kW factory system, real ROI, savings ₹18L/year, engineering design insights and performance analysis.
Industrial Solar Case Study India: 120 kW Factory System Saving ₹18 Lakhs Annually
Industrial solar is often marketed with attractive savings and fast payback claims. However, actual performance depends entirely on engineering design and system optimization.
This case study presents a realistic industrial solar project scenario in Maharashtra, based on engineering calculations, field patterns, and practical assumptions used in professional audits.
Project Overview
Location: MIDC Industrial Area, MaharashtraIndustry Type: Manufacturing UnitSanction Load: 180 kWAverage Monthly Consumption: 65,000 unitsTariff: ₹9.5/unitProposed Solar System: 120 kW
Step 1: Electrical Load Analysis
Before designing the solar system, a detailed load analysis was performed.
Key Findings:
- Base load (continuous): ~70 kW
- Peak load: ~140 kW
- Daytime consumption: 80%
Insight:
👉 High daytime consumption makes the facility ideal for solar.
This ensures:
- maximum self-consumption
- minimal export losses
Step 2: System Sizing (Engineering Approach)
Instead of maximizing rooftop capacity, system size was optimized based on:
- load profile
- roof area
- energy consumption
Final Design:
System Size: 120 kWPanel Type: 540W Tier-1Inverter: String inverter configurationMounting: Industrial rooftop structure
Why not 150 kW?
- excess generation would be exported
- lower financial return
👉 Correct sizing improves ROI.
Step 3: Energy Generation Estimation
Using real-world assumptions:
- CUF: 17%
- Losses (total): ~14%
Annual Generation:
~1,78,000 units/year
Step 4: Loss Breakdown (Realistic)
| Loss Type | % Loss |
|---|---|
| Temperature | 5% |
| Inverter | 3% |
| Wiring | 2% |
| Dust & Soiling | 2% |
| Shadow | 2% |
👉 Total Loss: ~14%
Step 5: Financial Analysis
System Cost:
₹55/W × 120 kW = ₹66,00,000
Annual Savings:
1,78,000 × ₹9.5 ≈ ₹16,91,000/year
O&M Cost:
~1.5% of CAPEX ≈ ₹99,000/year
Net Savings:
₹15,92,000/year
Payback Period:
~4.1 – 4.5 years
25-Year Projection:
- Total savings: ₹4–5 crore
- System degradation considered
Step 6: ROI Insights
Key Observations:
- ROI improves with tariff increase
- system efficiency directly impacts savings
- load matching is critical
Scenario Impact:
| Scenario | Impact |
|---|---|
| Tariff +5% annually | ROI increases significantly |
| 10% shadow increase | payback increases by ~1 year |
| Poor design | losses up to 25% |
Step 7: What Could Have Gone Wrong
If designed poorly:
Oversized System (150 kW)
- excess export
- reduced ROI
Incorrect Inverter
- clipping losses
- lower generation
Poor Cable Design
- voltage drop
- energy loss
👉 These mistakes could reduce savings by ₹3–5 lakh/year.
Engineering Insights from This Case
1. Load-Based Design > Roof-Based Design
Most installers design based on available space.
👉 Correct approach: design based on consumption.
2. Losses Matter
Ignoring losses leads to unrealistic ROI.
3. Electrical Integration is Critical
Solar must align with:
- load
- infrastructure
- distribution system
Industrial Relevance
This case is applicable to:
- manufacturing units
- warehouses
- processing plants
- cold storage facilities
Before You Invest in Industrial Solar
A ₹50 lakh–₹1 crore investment requires:
- engineering validation
- financial accuracy
- system optimization
Recommendation:
Before installing solar, ensure:
- independent system design
- realistic ROI calculation
- proper electrical integration
Next Step
If you are planning an industrial solar project:
Conclusion
This case study highlights a simple truth:
Solar savings are not created by panels.They are created by engineering.
Final Insight
Factories that treat solar as an engineering project:
👉 achieve maximum ROI
Those that treat it as an installation:
👉 often lose money