How to calculate the ROI of upgrading LED stadium lights?
ROI calculation requires the following data:
1. Initial total investment (I): Includes lighting fixtures, installation, control system, design fees, taxes, etc.
2. Annual electricity cost savings (S_elec): Original system annual electricity consumption (kWh) × electricity price ($/kWh) - New system annual electricity consumption (kWh) × electricity price.
3. Annual maintenance cost savings (S_maint): Includes bulb replacement costs (bulb unit price × quantity × annual replacement frequency), aerial work platform rental fees, labor costs, spare parts costs, etc. LED systems require very little cleaning and inspection, so this can be considered zero.
4. Other savings or revenue (S_other): For example, increased ticket revenue, broadcasting rights revenue, sponsorship fees due to improved lighting quality, and reduced air conditioning costs (LEDs generate less heat).
5. Total annual savings (S_total) = S_elec + S_maint + S_other.
6. Simple Payback Period (in years) = I / S_total.
7. Net Present Value (NPV) and Internal Rate of Return (IRR): Considering the cost of capital (discount rate), calculate the net return over a 10-year period.
Example: An initial investment of $80,000 for a venue, annual savings of $10,000 in electricity costs and $15,000 in maintenance costs, with no other income, results in a simple payback period of 80,000 / $25,000 = 3.2 years. Total savings over 10 years amount to $250,000. Subtracting the initial investment, the net return is $170,000. If local subsidies are available (e.g., $20,000), the payback period will be shorter. It is recommended to assume a 10-year lifespan for the LED lights in the calculation and consider the 1%–2% annual light decay leading to a decrease in illuminance (which may require earlier replacement).
At the same time, it is necessary to compare the consequences of not upgrading: the old system may frequently fail in the next few years, affecting venue operations, and this potential loss should also be quantified.
