Solar electricity generated during the day can be stored in the batteries for use at night or on cloudy days. Massachusetts’ SMART solar program requires batteries for solar projects over 500 KW, or enough energy to power between 70 and 80 homes, and smaller projects are incentivized to install batteries. While batteries help store the solar energy, they present safety hazards that are often overlooked when the facilities are approved by local governments. Battery energy storage (BES) can be potentially dangerous and harmful to the environment if they are not managed properly. BES systems contain a large amount of energy that can pose a fire hazard if not properly managed. Overcharging, overheating, and damage to the battery can cause a thermal runaway reaction leading to a fire or explosion.
The batteries can leak toxic materials onto the ground. The most common storage battery contains lithium ion, which is highly reactive with water and can spontaneously combust if exposed. These potential explosions and fires require specialized firefighting equipment and training for first responders. According to fire safety expert Milosh T. Puchovsky, in testimony before the Energy Facility Siting Board in 2022,
“Toxic and flammable gases are generated and released when batteries undergo thermal runaway and combustion. If the gases do not ignite before the lower explosive limit is reached, an explosive atmosphere inside of the BESS room or container can be created. Toxic and corrosive gases can also be produced and released as can oxidizing gases which accelerate the combustion process.”
In towns like Wareham and Carver, solar storage batteries are being installed in residential neighborhoods and near schools without adequate disclosure of the safety risks or conditions for dealing with a fire or explosion. These batteries pose hazardous waste issues for the future. The disposal of BES systems can be challenging and requires specialized treatment because of the hazardous materials they contain. Lithium ion batteries are not recyclable; they contain hazardous materials such as cobalt, nickel and manganese. If not disposed of properly, they can lead to soil and groundwater pollution. Local municipalities are not equipped to dispose of this waste.