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British researchers have assessed the cost of a 24V soluble lead flow battery optimized for photovoltaic applications.
The soluble lead flow battery (SLFB) is a promising small-scale energy storage technology, especially for emerging economies, due to its robustness, a proven 2000-cycle lifespan at the cell level, and the fact that its electrolyte can be made directly from spent lead-acid batteries.
However, technoeconomic models are needed to define and optimize the cost/performance ratio of a complete system.
Now, researchers from the University of South Hampton and the University of Sheffield (UK) have defined such a model for the first time and have used it in the design of a 24V system for a charging center in Sierra Leone.
A 1.64 kW, 4 h duration system was found to be optimal, before diminishing returns began. The simulated efficiency of this system was 59%.
The researchers found that the electrolyte for a 3.5 kW/14 kWh system would fit into a 1,000 liter IBC. They calculated that scaling up the unit from ~1.5 kW to ~3.75 kW reduces the cost of the IBC from $19.98/kWh to $8.74/kWh.
Methanesulfonic acid (MSA) was the largest cost component of the 4-h system, followed by graphitic bipolar plates. Both have low raw material cost and, in an optimistic scenario, would achieve a total component cost of <$62.45/kWh, half that of current NMC lithium-ion cells.
Specifically, the current cost of the components (including cell frame fabrication) is estimated to be between $122.39 and $149.87/kWh (excluding control and assembly), assuming that a deposit thickness can be reliably achieved. of 1mm. However, according to the researchers, both MSA and bipolar plates have the potential to drop in price in the future, as more efficient manufacturing techniques have recently been introduced.
Therefore, the researchers calculate that with reductions in the costs of MSA and bipolar plates, this range could drop to as low as $53.70-69.94/kWh, making DESS cheaper at the DC level than cells. lithium ion NMC.
The biggest risk to system cost is the inability to deposit lead and lead oxide reliably in the assumed thickness of 1mm, as finer deposits increase component cost and reduce efficiency.
“Since deposits of this thickness have not been tested over many cycles, there is a significant gap in knowledge of SLFB that future research needs to address,” the researchers wrote in “Predicting the cost of a 24V soluble lead. ” flow battery optimized for PV applications ”, recently published in the Journal of Power Sources. |
