Fronius And BYD Secure First Place In PV Home Storage System Inspection
The results of the “Energy Storage Inspection 2020”, a study conducted by HTW Berlin – University of Applied Sciences, were published at the start of March. The hybrid inverter, Fronius Symo GEN24 10.0 Plus, and the BYD Battery Box H11.5, impressed in the two reference cases examined and secured first and second place.
In the study, independent testing authorities tested the overall efficiency of 21 home storage systems and analysed how the PV systems and battery storage systems from the 14 participating manufacturers perform in combination. The study underlines the importance of the energy efficiency of the solar power storage units and notes: “In a less efficient system that was tested, nearly 1,100 kilowatt hours are lost annually due to high conversion losses - 600 kilowatt hours more than the winner from Fronius.”
The study calculates overall efficiency using the System Performance Index, or SPI. Two different reference cases were used for the assessment: One reference system combined a 10 kWp PV system with heat pump and electric car and assumes an average annual household consumption of 5,010 kWh/a. The second, more streamlined reference case analysed the SPI for a 5 kWp PV system with the same annual household consumption as in the 10 kWp scenario.
In the 10 kWp category, the combination of the Fronius GEN24 10.0 Plus hybrid inverter and the BYD Battery Box H11.5 performed extremely well and achieved a never before seen SPI value of 94%. It was the only combination in energy efficiency class A to secure first place and left the other systems trailing by a country mile. This duo also achieved excellent results in the 5 kWp class, scoring 92.3% - close behind the winner in second place. These two systems were the only ones to achieve energy efficiency class A in this category.
Maximum conversion efficiency
The Fronius BYD combination demonstrated outstanding values in the energy conversion paths examined. These values illustrate the conversion efficiency of the PV energy produced to loads, to batteries, from the battery to loads or from the grid to the battery. Here, the hybrid inverter GEN24 Plus skilfully plays on one of its strengths, integrated Multi Flow Technology. This not only enables simultaneous energy flows in all directions, but also the AC and DC coupling of the battery storage system. In the test, the Fronius Symo GEN24 Plus inverter achieved the highest efficiency for all energy flows in comparison with the other systems.