In recent testing of home storage PV systems carried out by the University of Applied Sciences (HTW) in Berlin, GoodWe’s hybrid inverters and high-voltage batteries were once again outstanding.
A total of 20 different storage systems in the 5 and 10 kilowatt power classes were examined to determine their System Performance Index (SPI) as part of the “Electricity Storage Inspection 2021”.
The two GoodWe hybrid inverters tested, the ET and EH, achieved an SPI of 93.4% and 91.2% respectively. With this exceptional system efficiency, the GoodWe 5000-EH secured 2nd place in the smaller reference case (5MWh/a consumption with 5kWp PV). The GoodWe 10k-ET also performed very well and was only 1.7 points away from the best-placed system in the second reference case (10 MWh/a consumption with e-car and heat pump).
The System Performance Index determined by the HTW researchers is an economic index and indicates by how much the tested storage system reduces electricity costs compared to an ideal storage system. The better the efficiency-related properties, such as conversion efficiencies, control speeds or standby consumption, the higher the cost savings achieved. The difference one point makes in terms of cost can be determined with a high degree of accuracy.
Another focus of the study is the design of the storage system. Simulation and analysis carried out shows that sizing the PV system as well as the storage system according to demand is particularly important from an economic standpoint. The larger the PV system, the higher the saving in CO2 emissions. Any suitable roof surface should be used to produce solar electricity in order to increase the degree of self-sufficiency and reduce CO2 emissions. The use of the two tested GoodWe hybrid inverters, 5000-EH and 10k-ET, and the installation of a simple PV storage system pays off for a homeowner, not only in terms of CO2 emissions, but also financially, as they can break even within seven years.
About the GoodWe ET Series
Name of Inverter: GoodWe ET Series, three-phase Energy Storage Inverter
Unique Selling Points:
● Maximum efficiency up to 98.2%
● Uninterruptible Power Supply
● Wide battery voltage range
● Fanless design, quiet operation
The three-phase hybrid inverter is compatible with a high-voltage battery and is perfectly suited to the storage market in Europe. Covering a power range of 5kW, 8kW and 10kW, the ET series allows up to 10% overloading to maximize power output and features an Uninterrupted Power Supply to inductive loads with an automatic switchover time of less than 10 milliseconds, providing grid-tied savings when the grid is up and off-grid independence when it is down or compromised.
About the GoodWe EH Series
Name of Inverter: GoodWe EH Series, Single-phase Energy Storage Inverter
Unique Selling Points:
• UPS level automatic switch in <10ms
• Wide battery voltage range 85~450V
• Large loads on back-up
• Up to 20% AC overloading
The GoodWe EH Series is a single-phase, grid-tied solar inverter specially designed for use with high-voltage batteries. The inverter features a “Battery Ready” option for users who might wish to eventually acquire a full energy storage solution; by simply purchasing an activation code, the EH can easily be upgraded to a complete ESS system. Communication cables come pre-wired, significantly reducing installation time, and the Plug & Play AC connector also makes operation and maintenance more convenient.
The EH is compatible with high voltage batteries (85-450V) and can automatically switch to back-up mode in less than 0.01s (UPS level), ensuring that critical loads experience no interruption. With a power deviation lower than 20W, this inverter is designed to maximize self-consumption. In addition, the fact that it takes less than 9 seconds to switch from grid to PV to supply power for heavy loads helps users avoid expensive intakes from the grid.