This is the real story of how an automotive parts manufacturer in Rayong Industrial Estate achieved a 3.8-year payback on their solar investment.
The Challenge
The factory was facing:
- Monthly electricity bills exceeding THB 4 million
- Rising TOU tariff rates (peak hour rates increasing)
- Pressure from overseas clients to reduce carbon footprint
- Large unused rooftop space (8,000 sqm)
The Solution
Red Solar designed and installed:
- 1.2 MWp rooftop solar system
- 2,182 × Red Solar RS-M550 monocrystalline panels
- Huawei SUN2000-100KTL string inverters
- Complete mounting and electrical systems
Project Details
| Customer Type | Automotive Parts Manufacturer |
| Location | Rayong Province, Thailand |
| System Size | 1.2 MWp |
| Business Model | Self-Build (EPC Turnkey) |
| Annual Generation | 1,680 MWh/year |
| Annual Savings | THB 5.5 million/year |
| CO₂ Reduction | 1,050 tons/year |
| Project Timeline | 45 days (design to commissioning) |
The Results
| Payback Period | 3.8 years |
| 25-Year Total Savings | THB 137 million |
Client Quote
“Red Solar delivered on time and on budget. Their factory-direct equipment pricing was 15% lower than competing quotes. The system has been running flawlessly for over a year now.”
— Somchai T., Factory Director
Key Takeaways
- Factory-direct equipment pricing significantly reduces project cost
- Professional EPC delivery ensures minimal production disruption
- Solar payback is under 4 years for well-designed industrial projects
- Long-term savings far exceed initial investment
