VRFB Home Storage https://www.pv-magazine.de/2023/02/23/prolux-solutions-lanciert-vanadium-redox-flow-heimspeicher/
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Prolux Solutions launches Vanadium Redox Flow Home Storage
With a redox flow storage, which is characterized by its compact dimensions and Modbus interfaces, the company Prolux Solutions wants to integrate the technology into home.
Prolux Solutions launches Vanadium Redox Flow Home Storage
With a redox flow storage, which is characterized by its compact dimensions and Modbus interfaces, the company Prolux Solutions wants to integrate the technology into home applications. The first model has a capacity of six kilowatt hours.
February 23, 2023 Marian Willuhn
Photo: Prolux Solutions
Redox flow batteries are now also available in small sizes for the home storage market. Prolux Solutions company launched sales of vanadium redox flux storage in the small applications segment this quarter . The technology is an alternative to lithium-ion batteries. The storage tanks hardly degrade at all and retain their original capacity even after decades. In addition, no rare elements are needed for their production. What sounds tempting has led to the technology being used in grid storage in recent years. So far, however, it has hardly played a role in the home storage market.
Prolux wants to change that now and says that the focus when developing the product was on miniaturizing the components. Previous versions were significantly larger, which is why this type of storage was less used indoors . The engineers have also provided the storage with a Modbus RTU RS485 interface. Heat pumps, for example, can be connected to the storage tank via this interface.
Six kilowatt-hour fridge
The memory with a capacity of six kilowatt hours should be as big as a refrigerator – two meters high and 60 centimeters wide. The installation is initially carried out without the aqueous vanadium electrolyte. Then it weighs 174 kilograms – with electrolyte it is 584 kilograms. The electrolyte is then filled out of canisters. Installation in places that are difficult to access is also possible, as the company reports. Also, everything comes pre-assembled. Installers only have to set up the cabinet and provide it with a power cable and a LAN cable for communication.
The single-phase AC-coupled solution can charge and discharge at two kilowatts. Three kilowatts are also possible for a short time, for example during the emergency power supply. The storage comes with its own battery inverter and can therefore only be charged with mains power. If you want to charge the storage system with a photovoltaic system, you still have to connect a photovoltaic inverter.
A DC-coupled solution with an external inverter or a hybrid inverter is under "testing," a company representative said during a press briefing Thursday morning. One challenge lies in the fact that flow storage and lithium storage work with different voltages. Inverters designed for use with lithium-ion cannot readily be used with a flux storage system.
Efficiency lower than lithium-ion competition
In terms of efficiency, the memory performs significantly worse than its lithium counterparts. For the path from the grid to the battery, the efficiency is given as 78 percent. Saving is more efficient. It should be 83 percent. But the vanadium redox flux technology also has advantages. The efficiency is subject to a degression of two to three percent in the first few years. After that, the battery should be stable for 20 or 30 years, the company says.
The electrolyte is also characterized by stability over decades. With this type of battery, it shows hardly any signs of aging. After 20 years, the manufacturer still promises 95 percent of the capacity. If the electrolyte is contaminated or oxidized after decades, you can simply drain it and fill with a new electrolyte. The old electrolyte can also be recycled.
In general, the battery is constructed in such a way that all components can be replaced or repaired. The company declined to comment on the price. Prolux Solutions announced that the overall costs should be competitive with those of lithium-ion batteries. Storage units with a capacity of 10 and 15 kilowatt hours and an output of four kilowatts are planned for the future.