sunny island

[Cor van Houtum]

please give me all your input on the Sunny island
need no articles or other read stuff , but input from people who have or are still working with these units,
I mean the Sunny island in combination with other on grid inverters for wind and sun.
ballance of systems , battery life etc.
Combinations of SMA and power-one.
3 phase with 3 sunny islands .
load of 120 and 208 volts at the same time.

End of the month i am at SMA GERMANY for a sunny island training and i want to
prepare the field expierence questions.

love to hear from you

Cor

[Rob Beckers]

Hi Cor,

Here's one for you: Our customers have had problems combining a Sunny Island with a Power-One wind inverter. Reason is that the Sunny Island used the frequency of the voltage that it generates to indicate what it wants the other inverters to do (if you combine this with other SMA inverters, such as SunnyBoy or WindyBoy, to do AC-coupling). When the batteries get full, the frequency changes away from the default 60Hz or 50Hz (the latter for your region), and that in turns makes any SunnyBoy or WindyBoy gradually produce less power, to avoid overcharging the batteries. This works as long as you use SMA inverters only. This fails miserably with other grid-tie inverters, because they will switch off hard once their frequency limit is reached. The effect is that with a Power-One wind inverter it will shut off the inverter at about 70% full batteries, it will never be able to fully charge them. There does not seem to be a way to stop the Sunny Island from doing this.

-RoB-