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Is Investing in Solar PV Systems Worthwhile?

February 5, 2026

Many business owners wonder whether installing a solar PV system provides a worthwhile return on investment (ROI). To provide clarity, Solar PPM presents a preliminary guide on how to calculate the break-even point for your solar investment.

How to Calculate the Break-Even Point for Solar Installations

1. Determine System Size Based on Total Consumption

each industrial facility, depending on electricity usage patterns and operating hours. Solar PPM offers expert consultations at no cost to help determine your optimal system size.

Example: A 300 kWp installation (equivalent to 300,000W).

2. Calculate Total Investment Cost

Installation costs fluctuate based on system size, mounting type, and roof structure.

Example: Assuming an installation cost of 25 THB per Watt.

Total Investment: 300,000W x 25 THB/W = 7,500,000 THB.

3. Estimate Annual Energy Production

Since solar intensity varies throughout the day, we use “Peak Sun Hours” (PSH) for calculation. On average, Thailand provides approximately 4 hours of effective sunlight per day.

Calculation: 300 kWp x 4 hours = 1,200 kWh per day.

4. Calculate Annual Electricity Savings

Based on the electricity tariff as of August 2023:

Standard Rate: 5.09 THB per unit (kWh).
Daily Savings: 1,200 kWh x 5.09 THB = 6,108 THB per day.
Annual Savings (365 days): 6,108 x 365 = 2,229,420 THB per year.

Accounting for Operation & Maintenance (O&M): Assuming an annual O&M cost of approximately 200,000 THB (actual costs depend on system scale):

Net Annual Savings: 2,229,420 – 200,000 = 2,029,420 THB per year.

5. Calculate the Break-Even Point (Payback Period)

With a 7,500,000 THB investment and annual savings of 2,029,420 THB:

Payback Period: 7,500,000 / 2,029,420 = 3.69 Years. Since a high-quality solar system has an operational lifespan of 25 years, you will enjoy pure profit for the remaining 21.31 years.

6. Leverage BOI (Board of Investment) Incentives

If your facility qualifies for BOI investment promotion, you may receive a 50% corporate income tax exemption on the project value, applicable within a 3-year period.

Tax Deduction: 7,500,000 THB x 50% = 3,750,000 THB.
Adjusted Investment Cost: 7,500,000 – 3,750,000 = 3,750,000 THB.
Optimized Payback Period: 3,750,000 / 2,029,420 = Only 1.84 Years.

Under this scheme, the profitable period extends to 23.16 years. When calculated against your annual savings, the total lifetime benefit reaches approximately 47,001,367.2 THB.

Conclusion

A single investment in a solar PV system can significantly reduce operational overhead and substantially increase long-term profitability for your facility.

Note: This is a preliminary calculation. For a comprehensive financial analysis tailored to your specific facility, please contact our specialists.

Consult with Solar PPM today: Line Official: @solarppm