Energy Efficiency - The Core Advantage

Metal halide efficacy: 80–100 lm/W (at rated life start). After 4,000 hours (about 1.5 years at 2-shift operation), MH output drops to 60–70% while consuming the same power - effective efficacy falls to 50–70 lm/W. LED highbay efficacy: 130–160 lm/W, maintained at 90%+ throughout its 50,000-hour life. Replacement ratio: 100W LED highbay replaces 250W MH. 150W LED replaces 400W MH. 200W LED replaces 600W MH. Energy saving: 55–65% immediately upon replacement, growing to 65–70% as the old MH ages further.

Warm-Up Time - The Hidden Productivity Cost

Metal halide requires 3–5 minutes to reach full brightness from cold start, and 10–15 minutes to re-strike after a power interruption (must cool down first). In a factory with frequent power fluctuations (common in Indian industrial estates), MH lights cause 10–15 minutes of dim lighting after every trip or interruption. Workers slow down, quality errors increase, and accidents happen in dimly lit conditions. LED is instant-on from cold or hot - full brightness in under 1 second. For factories running night shifts or with power supply issues, this alone justifies the switch.

Maintenance Cost - The MH Hidden Expense

MH lamp replacement frequency: every 6,000–10,000 hours (2–3 years at 2-shift operation). For a factory with 100 MH highbays: lamp cost ₹1,200–₹2,500 per lamp × 100 = ₹1.2–₹2.5 lakh per replacement cycle. Access cost (scissor lift or scaffolding for 8–12m ceiling): ₹500–₹2,000 per lamp. Total: ₹1.7–₹4.5 lakh every 2–3 years just for lamp maintenance. LED highbays: essentially zero lamp replacement for 15 years. Only occasional driver failure (1–3% per year) requiring ₹800–₹2,000 driver replacement without touching the fixture body.

ROI Calculation for 100-Highbay Factory

Scenario: 100 × 250W MH replaced with 100 × 100W LED, running 16 hours/day, 300 days/year. Annual electricity saving: 100 × 150W × 16h × 300 = 72,000 kWh. At ₹7/unit: ₹5,04,000/year. Lamp maintenance saving: ₹2,00,000/year (amortised). Total annual saving: ₹7,04,000. LED upgrade cost (100 × 100W LED highbay at ₹5,000 + installation ₹1,000 each): ₹6,00,000. Simple payback: 6,00,000 ÷ 7,04,000 = 10 months. After payback: pure saving of ₹7 lakh/year for 14+ more years of LED life.