LED vs. HPS: lighting in comparison

The lighting comparison between LED and HPS is one of the most important decisions for indoor growers:

**LED technology:**

*LED advantages:*

- Higher energy efficiency (2.0-3.0 µmol/J)

- Less heat generation

- Longer service life (50,000+ hours)

- Full spectrum without change

- Precise spectrum control

*LED disadvantages:*

- Higher initial cost

- More complex technology

- Quality differences between manufacturers

- Less penetration with thick canopies

- Lack of infrared heat

*LED types:*

- Full Spectrum LEDs (full spectrum)

- COB LEDs (Chip on Board)

- Quantum boards

- Bar-style LEDs

- Blurple LEDs (obsolete)

**HPS technology:**

*HPS advantages:*

- Lower acquisition costs

- Proven technology

- Deep light penetration

- Infrared heat helps in winter

- Simple retrofitting

*HPS disadvantages:*

- Higher power consumption

- Strong heat development

- Shorter service life (10,000-20,000 hours)

- Spectrum deteriorates

- Additional cooling required

*HPS systems:*

- Standard HPS (High Pressure Sodium)

- Ceramic Metal Halide (CMH/LEC)

- Double Ended HPS

- Magnetic vs. Digital Ballasts

- Reflector designs

**Energy Efficiency:**

*Power consumption comparison:*

- LED: 30-50W per m² less

- HPS 600W ≈ LED 400W

- Annual savings: 200-400€

- ROI through electricity savings

- Lower environmental impact

*Heat management:*

- LED: Minimal additional cooling

- HPS: Significant cooling required

- Consider air conditioning costs

- Winter: HPS heat can be advantageous

- Summer: LED significantly better

**Spectrum analysis:**

*LED spectra:*

- Precise wavelength control

- UV-A and Far-Red targeted

- Vegetative: More blue

- Flowering: More red

- Constant spectrum quality

*HPS spectra:*

- Natural, proven spectrum

- Strong orange/red component

- Little blue for vegetatives

- Spectrum deteriorates

- MH for vegetative phase

**Yield comparison:**

*LED yields:*

- 0.8-1.5g per watt possible

- Depends on the quality of the LED

- Better trichome development often

- More compact plants

- More uniform canopy illumination

*HPS yields:*

- 0.5-1.2g per watt standard

- Proven results

- Deeper light penetration

- Stretchier plants

- Centralised hotspots

**Cost analysis:**

*Acquisition costs:*

- LED: 300-800€ per m²

- HPS: 100-300€ per m²

- LED amortises over 2-3 years

- Quality is decisive with LED

- HPS immediately cheaper

*Operating costs (5 years):*

- LED: Lower electricity costs

- HPS: Higher total operating costs

- Light source replacement with HPS

- Additional cooling costs

- LED cheaper in the long term

**Thermal management:**

*LED heat:*

- 65-70% light, 30-35% heat

- Heat dissipated via heat sink

- Less room heating

- Heating required in winter

- Easier climate management

*HPS heat:*

- 40% light, 60% heat

- Direct infrared radiation

- Strong room heating

- Air cooling essential

- More complex climate management

**Recommendations for use:**

*LED ideal for:*

- Small to medium setups

- Summer cultivation

- Energy efficiency important