Always On Energy about Inverter Temperature degrading .

🌞 Solar Insight for Johannesburg Clients:

How Growatt Inverters Handle the Heat compared to Lux Inverters.

As temperatures in Johannesburg regularly climb to 38°C, many solar owners assume more sun means more power. But here’s the reality: heat can hurt performance.

Growatt inverters—like most high-quality models—are designed with automatic temperature derating. That means when ambient temperatures rise beyond optimal levels (typically above 40°C), the inverter intelligently reduces its power output to protect internal components from thermal stress.

🔧 Why it matters:

• At 38°C, you're approaching the threshold where efficiency begins to drop.

• Derating is not a fault—it’s a built-in safeguard to extend system life.

• Expect a 0.5–1% drop in output per 10°C rise above nominal operating temps with fan air cooling.

• 🔍 Why Growatt Holds Closer to 9kW While Lux Drops to ~8kW

• 1. Active vs passive Thermal Management Architecture

• Growatt inverters typically feature more robust heat dissipation—larger heatsinks, better airflow channels, and in some models, active cooling fans.

• LuxPower inverters, especially the LXP5K and LXP10K series, rely more heavily on passive cooling. Once ambient temps exceed ~35–40°C, internal temps rise faster, triggering earlier and steeper derating.

• 2. Derating Curve Behavior

• Growatt’s derating curve is more gradual. At 38°C ambient, it may only reduce output by ~3–5%, resulting in ~9.5–9.7kW AC output.

• LuxPower’s curve is steeper, with some models showing up to 10–15% derating above 38°C, especially if installed in poorly ventilated or sun-exposed locations. That’s where the ~8.0kW figure comes from.

• 3. Installation Sensitivity

• Lux units are more sensitive to installation conditions—wall-mounted inverters in direct sun or enclosed spaces can reach internal temps well above ambient.

• Growatt’s design tolerates ambient-to-internal temp deltas better, maintaining higher output under similar conditions.

• 🧠 What This Means for you as the Solar client.

• Inverter placement, ventilation, and ambient temperature matter—not just brand specs.

• Knowledge of Inverter temperature derating.  matters.

• 4 Power throttling in Inverter Temperature Management.

• Both  LuxPower and Growatt inverters do not reduce output voltage to achieve thermal derating. Instead, they use current limiting and internal control logic to reduce power output while maintaining voltage within grid-compliant limits.

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• 🧠 Example: 10kW Inverter at 38°C Ambient

Inverter	Voltage	Current	Power Output	Derating Method
Growatt	~230V	~39A → 36A	~9.0kW	Current limiting
LuxPower	~230V	~39A → 34A	~8.0kW	Current limiting

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• 5.Conclusion;

• This is another reason why inverter placement, airflow, and oversizing PV arrays are critical for summer performance. Solar Systems needs design from a clear specification to have a reliable, long lasting Power Generation System, as you can see.

• Choosing to limit an Inverter to a maximum power output of 80% will be wise.

        Our next post will add the Victron Inverter to this comparison and don’t think this comparison is complete.

📊 For clients investing in long-term solar reliability, understanding this trade-off is key. It’s why we factor temperature derating curves into every system design—especially for rooftop setups exposed to direct sun.

#Solarsystems#Solareducation#BMS#Solarbatteries#Solarinverters#Offgridsolar#PVoversizing#Invertertemperaturedegrading.