DOC №070SEC: GUIDESREV: 2026-05-16AUTHORED
LED vs HPS Grow Lights — 2026 Cost & Yield Math
LED won. Modern Samsung LM301H quantum boards beat HPS on PAR/W, run cooler, last 5× longer — and the price gap is closed. Full numbers.
BY ROOTLESS FARM
Numbers
| Factor | Modern LED (LM301H+) | HPS double-ended |
|---|---|---|
| PAR efficacy | 2.7-3.0 μmol/J | 1.6-1.8 μmol/J |
| Heat output | low | very high |
| Lifespan | 50,000 h | 10,000 h |
| 600 W replacement cost (5 yr) | $0 (still works) | $400-600 |
| Upfront (1m² flowering) | $350-500 | $150-200 |
| Total 5-yr cost | $500 | $800-1100 |
What changes if you switch
- AC requirement drops by 30-40%.
- VPD targets shift slightly (lower leaf surface temperature).
- DLI stays the same — just hit your target μmol with less wattage.
FAQ
2 entries- Q01Is HPS ever still worth it?
- For a single 1m² flowering tent on a tight upfront budget where ambient temp is below 18°C — maybe. Otherwise no.
- Q02Do LEDs really last 50,000 hours?
- At rated drive current, yes — but most cheap fixtures run their diodes hot. Buy MeanWell-driver fixtures with under-driven diodes.