ENERGY STORAGE
HANDLE WITH CARE: SAFEGUARDING THE USE OF BATTERIES FOR ENERGY STORAGE As the UK continues its transition from fossil fuels to renewable energy sources, the large scale energy storage adoption ahead is evident. Lithium-ion (li-ion) batteries have a crucial role to play, and managing their unique fire risks is key. James Mountain, Sales and Marketing Director, Fire Shield Systems, explores the existing regulation surrounding battery manufacture, storage, transportation, installation and use, looking closely at the implications of the wide-scale adoption for building design, fire protection and suppression. 36
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he ongoing shift towards sustainable energy sources has caused an increased reliance on battery energy storage systems (BESSs). These systems are designed to smooth out the energy supply from renewable sources, such that when power input is low, output remains consistent, for example, storing solar energy for night use. However, this can mean the BESS holds large quantities of energy for long periods of time, which presents a number of fire risks requiring tailored solutions.
Without disconnection or rapid control, thermal runaway can spread between cells, self-propagating the fire. Once a battery enters thermal runaway, it is often very intense and challenging to control. It can take days or weeks to fully extinguish, and residual energy can cause electric shocks even once the fire is put out. As a result, if a battery enters this state, it is often contained and left to burn out naturally, frequently causing whole system loss.
THE RISKS FOR BESSS
Failure in the BESS control systems can result in overheating, which leads to increased fire risk if not controlled properly.
• THERMAL RUNAWAY Many BESSs include li-ion batteries, as they are well suited to the application, as a result of their high energy density and ability to fully discharge, without impacting the battery’s longevity. This means thermal runaway is a key risk. This is where internal battery defects, mechanical failures/damage or overvoltage in li-ion batteries results in excess heat, which creates more heat. This causes extremely high temperatures, build up of toxic gasses and potential rupture of the battery cells, resulting in fire or even explosion.
ENERGY MANAGER MAGAZINE • MAY 2021
• FAILURE OF CONTROL SYSTEMS
• HYDROGEN EVOLUTION For lead-acid batteries, where suitable ventilation methods are not in place, excess hydrogen can increase the risk of fires and explosion for the BESS. As BESS are starting to be rapidly adopted across a wide range of industries and buildings, managing these risks is increasingly difficult – and many buyers are not aware of the potential hazards and dangers of the systems. Similarly, site selection for the storage
