Storage Highlights countdown #3: SMA large-scale storage solution

pv magazine has evaluated and assessed a range of energy storage innovations and applications for the upcoming Energy Storage Europe in Düsseldorf (March 13-15).

Our highlights ranking awards the top 10, based on the scores of an expert, independent jury, which assessed a total of 24 candidates. The full ranking is published in the pv magazine energy+storage special issue, created in cooperation with Messe Düsseldorf.

After publishing, last week, a preview on the fifth and fourth technologies in the ranking – Electrochaea’s scalable methanathan plant and Fraunhofer ISE’s Cell-Booster – over the next few days, we will publish in descending order the Top 3 products and innovations that were awarded for their excellence. This time we approach…

#3: SMA large-scale storage solution

In 2017, SMA introduced its large-scale turnkey solution Medium Voltage Power Station to the global market, and now the company reports it has concluded contracts with a total capacity of 400 MW. One container has an output power of 5.5 MW.

Unique to this solution is that the Sunny Central Storage with grid forming capacities acts just like a rotating mass in a power grid, writes the company in its submission to pv magazine’s highlights. There is a distribution of responsibility between Grid Controller and Sunny Central Storage. Energy flows and general operational tasks that take place within a few hundred milliseconds to seconds or even hours are carried out on the Grid Controller, while functions regarding grid stability that need reaction within milliseconds or less are located in Sunny Central Storage, directly avoiding any communication to fulfill these tasks.

The technology mimics the function of rotating mass in the grid to load and subsequent frequency changes. When load increases,  rotating masses are decelerated, but their inertia dampens the effect until the generator power is increased.

While the jurors generally doubt that the solution is as unique as the company claims, most acknowledge other strengths of the product. One juror emphasizes it’s importance in grid connected installations to reduce the share of  conventional power plants, which today guarantee the frequency stability with their rotating masses. Another emphasizes the pure size, i.e. the 5.5 MW power output of these devices, the long track record of SMA in this field, and the contribution of the company to bring down costs.

“Out of all the entries SMA has probably submitted the most commercially advanced offer, rather than a technical innovation”, says juror Julian Jansen of IHS. “Building on their strength in the power conversion system market, SMA has used the experience to build a turnkey solution which can target multiple applications and seamlessly integrates into existing infrastructure.”

SMA has deployed the system in places such as the island St. Eustachius in Netherlands Antilles. The first step was a fuel saving system. In 2017 it was complemented with the new inverter and battery system, which is now available “off the shelf” (see photo above). PV penetration now can now reach 100% during the day, says the company.

Volker Wachenfeld of SMA is convinced of the uniqueness of the product. “We supplied island-ready battery inverters, PV inverters, batteries, medium voltage connection, the power management system with the interface to the generators, and the SCADA”, he explains.

He goes on, “We regulate the load balancing, create a seamless transfer at diesel shutdown, provide instantaneous reserve, and primary and secondary control power.” Typical systems for primary control power need several hundred milliseconds to send the command to the responding units. “We can initiate a reaction within the time of a half wave,” he says, which corresponds to about 10 ms. This reaction time has to be adjusted according to the characteristics of the individual grid in order to guarantee the security of the supply, also when load in the grid changes quickly.

SMA’s booth at Energy Storage Europe can be found at Hall 8b / B22.

Find out #2… in the ranking on Monday, March 5.

The Energy Storage Highlights Jury comprises:

  • Logan Goldie Scot, who heads up the Energy Storage insight team at Bloomberg New Energy Finance.
  • Tobias Federico, Founder and Managing Director of consulting institute Energy Brainpool.
  • Dirk Uwe Sauer, Professor of Electrochemical Energy Conversion and Storage Systems Engineering at RWTH Aachen University.
  • Julian Jansen, a Senior Market Analyst at IHS Markit Technology.
  • Stephan Schnez, Senior Scientist in Corporate Research at ABB in Switzerland.

Read more about the Energy Storage Highlights ranking, criteria and the selection process in the pv magazine energy+storage special.