Solar Energy International recently added a brand new SMA Sunny Island AC-coupled system to it’s battery-based hands-on training in the Paonia, Colorado lab yard. Danny Bailey, SEI’s PV Lab manager weighs in on system:

The new Sunny Island AC coupled system is comprised of the following components: The primary battery based inverter is an SMA, Sunny Island SI4548 which has a 4500W output at 48Vdc. This is accompanied by a Grid-Direct SMA SunnyBoy4000TL-22-US that is connected to a 4KW CertainTeed, Apollo II BIPV solar shingle array.

The point of common coupling integrates SMA’s Smartformer, which is an autoformer that takes the 120V output of the Sunny Island and steps up the voltage to 240V and enables the Sunny Island to be compatible with the 240V output of the Sunny Boy. The Smartformer also contains a Bypass switch, as well as a load shedding contactor to regulate loads in the backed up loads panel. The system also has an automatic transfer switch to show students how to incorporate a generator into this system, as well as a backed up loads panel in order to run loads in the event of a grid failure.

The battery for this system has been provided by Blue Planet Energy. The battery, Blue Ion, is Lithium Iron Phosphate Li-FePo4, and is considered one of the safest lithium chemistries on the market today. The battery capacity is 16kWh and is comparable to a lead acid bank of 32kWh because of the capability of discharging this battery to 100% depth of discharge (traditional lead acids batteries are not recommended to go below 50% DoD). Not only does the Blue Ion pack high power density, but it is installed in a very sleek cabinet along with the BMS and a main overcurrent protection device, and takes up about half the space of a similar capacity lead acid battery bank.

On top of the previous attributes that the Blue Ion battery offers, there are no requirements for venting or fire suppression (some of the lithium options available today require specially engineered fire suppression systems due to there inherent fire danger), which is a huge benefit when trying to install these in a residence. A huge thanks goes out to Blue Planet Energy and our SEI instructor Kyle Bolger helping SEI get it’s first Lithium Ion Battery!

Come train on an emerging storage technology, Lithium Ion at SEI to stay on top of the latest trends in solar+storage technology.