HTW Ranks Combination of BYD Battery-Box and Top Inverters as Most Efficient Battery Storage Solution

The Battery-Box system by BYD Co Ltd, one of the world’s largest manufacturer of rechargeable batteries, has been ranked as the most efficient energy storage system for the third consecutive time in the Stromspeicher-Inspektion 2020 evaluation by the Berlin-based University of Applied Sciences (Berliner Hochschule für Technik und Wirtschaft, HTW).

The report, published yesterday, evaluated 21 systems. The modular BYD Battery-Box system dominated the top 20 in combination with equally efficient inverter solutions by partners such as Fronius, KOSTAL, Kaco, SMA, and GoodWe.

The evaluation is based on the System Performance Index (SPI) developed at HTW Berlin which looks into general system efficiency, taking into account factors such as different energy conversion pathways, dynamic control losses and settling times.

The following example from the findings shows how important the energy efficiency of solar power storage systems is: In a less-efficient tested system, almost 1,100 kWh would be lost annually due to high conversion losses. That’s 600 kWh more than with the top-ranked combination of Fronius and the BYD Battery-Box. “The energy turnaround needs efficient electricity storage,” said Volker Quaschning, professor for regenerative energy systems at HTW Berlin and co-author of the study.

Julia Chen, global sales director for BYD Battery-Box, said: “We are delighted to be recognized as the most efficient energy storage system for the third consecutive time together with our inverter system partners. The survey data provided by HTW Berlin demonstrates how important full transparency of all system data is to estimate the overall efficiency. This is an important insight for both installers as well as end-customers in choosing a suitable energy storage system.”

The overall conclusion by HTW regarding the survey results was positive: More and more developers are paying attention to low storage losses when developing new storage systems. By focusing on high efficiencies in the partial load range and low standby consumption, many manufacturers were able to significantly improve the efficiency of their products.