On Tuesday, German commercial storage system manufacturer, Tesvolt, has been commissioned to supply the world’s largest decentralised off-grid storage system in the eastern province of Rwanda, East Africa.
The intension of the system is to act as a mini-grid when the national power grid cuts direct supply.
The company is set to deliver a lithium storage system with a total capacity of 2.68MWh, which will provide water pumps to an agricultural project with emergency power, the manufacturer said in a company statement. The 3.3MW solar power plant and the storage system are being engineered and constructed by the international system integrator, IdeemaSun energy.
Decentralised power system
Simon Schandert, Director of Engineering at Tesvolt explains: “In Rwanda, the power supply fails three or four times a day for between 5 and 45 minutes. For this reason, an important criterion in the call for tender was that the storage system is able to absorb electricity from the PV power plant and release it again as quickly as possible.”
He added: “Only very powerful off-grid storage systems can supply the necessary emergency power several times per day, and there are only a few storage systems on the market which meet these requirements.
“A further selection criterion was the necessity for the entire storage solution to be as reasonably priced as possible.”
The company will provide 134 fully assembled lithium storage systems for the 44 water pumps.
According to the German firm, the storage system will supply the irrigation project with clean and safe emergency power, also boosting yields in local agriculture. This should improve the living conditions of around 2,000 farmers, who currently live in extreme poverty.
In total, 402 Sunny Island charge controllers from SMA are to be deployed for the project. In the event of power cuts, the storage system will act as a mini-grid, enabling the PV power plant to continue running.
Every cell in the storage system is monitored
Falling in line with preventative maintenance, the battery management system monitors each individual cell when the system is in operation, identifying any faults before the damaged cells completely fail.
“If a cell is defective, the installer only needs to exchange that single cell, unlike in conventional storage systems where the entire battery block has to be replaced,” the company explained.
Featured image credit: Tesvolt