SMA unveils high voltage Tesla storage system

Last week SMA presented its new inverter for storage deployment, to be coupled with Tesla Energy batteries. The Sunny Boy Storage 2.5 will be released onto the German market at the latest in May, with wider European and Australian released scheduled for later in the year.

The high voltage storage power electronics unit is a customized string inverter is AC coupled to allow the battery to be connected to a standard solar string inverter and also to a home or businesses mains grid connection.

SMA presented the Sunny Boy Storage 2.5 at the OTTI PV Symposium, in Germany last week. The new battery unit picked up an Innovation Award at the event.

The design has several advantages, according to Martin Rothert, head of product management at business unit off-grid and storage at SMA "[These advantages] allowed us to reduce costs significantly,” said Rothert.

Compared to SMA’s existing AC-coupled storage product the Sunny Island, the Sunny Boy Storage 2.5 will come in at half the cost. Because some additional parts that are necessary for the Sunny Island are not required for the 2.5, SMA estimates the cost reduction totals 56%. Based on current webshop prices for the Sunny Island, the Sunny Boy Storage should not cost much more than €1,000 (US$1,100), to be a relatively inexpensive storage system, when coupled with the Tesla battery.

The Sunny Boy Storage 2.5 with Tesla PowerWall is offered with 7 kWh of capacity and sold through wholesalers in Germany. SMA says that by mid-year, two or maybe four more types of high-voltage batteries from other manufacturers will be coupled with the SMA power electronics solution. The SMA device operates a single phase and has a maximum discharge power of 2.5 kilowatts. It can be connected in parallel, which can then be coordinated jointly with the energy management of the Sunny Home Manager. It can be installed outdoors.

"We deliberately decided against DC coupling, “said Martin Rothert. The decision was driven by clear market signals that AC coupling is prefered. This, says Rothert, delivers increased flexibility.