Systems designed for tropical climates? What does that mean?

Re: Systems designed for tropical climates? What does that mean?

Only two things I can think of is that they have 4,400 watts of solar panels on a 4,000 watt inverter.

One is that in cold climates, the solar panels can output more energy (Vmp rises as the temperature falls). But the inverter will still work fine--it just limits its output current to max. spec.... Safely, no fuss, no mess.

The other is because the Vmp and Voc rises in very cold weather, it is possible that their Series/Parallel arrangement of solar panels would exceed Vinput-maximum for the inverter in sub-freezing temperatures (basically, Voc--voltage open circuit cold or Vmp cold).

The design would have to be modified to pull one or two solar panels out of each series string to keep the solar array Vmp/Voc cold within the inverter's input limits.

Their limits seem to be:

Voc=600 V
Vmp=220 – 480 V @ 208 V
Vmp=250 – 480 V @ 240 V
Start Voltage=285 V

Guessing that they use 2x 12 series Kyocera Solar Panel 185 Watts 23.60 Vmp:

• 12 * 23.6 volt = 283 volts Vmp at STC

Looking at 60F to 100F we get:

• 12 modules Voc-cold Vmp-hot
• 12 Modules 366.01 222.43

And at 0F to 90F:

• 12 modules Voc-cold Vmp-hot
• 12 Modules 408.41 229.49

So... No expert here on SunnyBoy systems... But it would sort of look like the system is running a bit low in the DC input voltage range if operated on 240 VAC system with either a Hot or Cold weather installation. Vmp-hot is less than the 250 VDC needed for operation on a 240 VAC line (typical 120/240 usage for a North American home).

-Bill