AllCell Technologies released a white paper comparing the economics of lithium-ion and lead acid batteries for stationary energy storage systems (ESS). Even though the initial purchase price of lead acid batteries is one-fifth the price of lithium-ion, when analyzed on a full life-cycle basis lithium-ion batteries are now cost-competitive in moderate climates and lower cost in hot climates. As solar photovoltaic costs continue to fall, the lightweight, long life cycle, and deep discharge capacity of lithium-ion battery systems will enable a growing range of mobile, portable, and off-grid products and applications to become economically feasible.
The analysis included a case study of a system requiring 50 kilowatt-hours of electricity per day, and compared valve regulated lead acid (VRLA) batteries to AllCell’s standard ESS modules in a moderate climate of 25°C (77°F) and a hot climate of 33°C (91°F). For the lead acid system, after taking into account the lower depth of discharge, climate-adjusted cycle life, and increased transportation and installation costs, the total cost per kWh delivered over 5 years came out to $0.34 in the moderate climate and $0.67 in the hot climate. The lithium-ion system came out to $0.40 per kWh delivered, 18% higher than lead acid in the moderate climate but 40% lower in the hot climate. The driver of this large difference is the reduced cycle life of lead acid in hot environments. The eight degree Celsius increase in average temperature between moderate and hot climates cuts the estimated cycle life of lead acid batteries in half, while the lithium-ion battery maintains the same cycle life in both environments.
AllCell off-grid ESS system used for solar EV charging in Amman, Jordan
The lithium-ion modules analyzed included AllCell’s proprietary phase change material (PCM) composite, which improves the cycle life of lithium-ion cells by passively absorbing and distributing heat. When a battery is placed in a hot outdoor environment, the PCM can absorb heat during the day and release it back into the atmosphere at night. Including PCM thermal management in battery modules enables the production of compact, lightweight, long-lasting energy storage systems. In addition to hot environments, the technology is ideal for mobile, portable, rooftop, and off-grid applications.
According to AllCell CEO Said Al-Hallaj, “Innovative system integrators are beginning to realize that lithium-ion’s longer cycle life justifies the higher initial cost in the right environment. Initial purchase price is only one input into the true life cycle economics. The more remote and rugged the installation site, the less important upfront cost becomes and the more important factors like cycle life, maintenance, transportation cost, size, and weight become.”