Battery energy storage systems
Make sure a licensed electrician installs your battery energy storage systems (BESS).
Incorrect installation can lead to:
- electric shock
- flash burns
- exposure to hazardous chemicals.
Your licensed electrician will test and commission your BESS in accordance with the manufacturer’s instructions and relevant standards.
There are three main types of BESS:
- a pre-packaged battery module (enclosed factory connected batteries)
- a pre-packaged system (enclosed factory connected batteries with other components such as a charger control or inverter)
- a custom-made battery bank (individual batteries installed with other components and interconnected).
Talk to your licensed electrician to make sure you select one that suits your requirements such as price, available space and ease of operation and maintenance.
Select the right battery technology for your application
A range of battery technologies are available in Australia. This could include, but not be limited to:
- lead-acid (advanced, flooded-cell and sealed)
- lithium (ion and polymer)
- nickel-based (metal hydrides and cadmium)
- flow (zinc bromine and vanadium redox)
- hybrid ion.
Different battery technologies and chemistries have different performance capabilities, and different requirements for installation, operation and maintenance.
Make sure you know:
- how to safely operate, maintain and shutdown the system in an emergency
- what safety warnings and lights mean
- which safety data sheets are required and where they should be located
- what maintenance is required, when it should be scheduled and who should do it.
Control the electrical and chemical hazards
Be aware of your chosen technology’s hazards such as overheating, over-charging or emissions from hazardous chemicals and know how to safely operate the system.
Battery cells have the potential to deliver a severe electrical shock when interconnected as battery banks, reaching hazardous voltage levels. There will also be 240 volt rated parts or other components present on the energy regulators, inverters etc, that have hazardous voltages.
A battery has sufficient energy to cause an electric explosion called an arc flash if a short circuit or fault occurs. An arc flash can have temperatures above 12,000°C, capable of melting metal or causing fires and explosions. Generally, higher battery energy storage capacities have a higher risk of arc flash.
Fire and explosion
Most lead-acid batteries generate hydrogen and oxygen gases when charging. Other battery types also emit flammable gases and need adequate ventilation to avoid an explosion or fire.
Lithium-ion batteries do not produce any exhaust gases during normal operation, but they can produce flammable gases if there is a fault.
Fire and explosions can also result from excessive temperatures (either under normal operating conditions or due to an overload), component failure, short circuit or loose connections.
Battery casings can degrade or be damaged from a variety of impacts. They can also rupture as a result of excessive temperatures generated from a change in chemical reaction from over-charging. If a battery casing is ruptured, the fluid or gel (electrolyte) inside can leak, resulting in toxic fumes, burns, corrosion or explosions.
Best Practice Guide for battery storage equipment – electrical safety requirements
Industry associations involved in renewable energy have developed a best practice guide for battery storage equipment.
This guide will assist in providing a minimum level of electrical safety for lithium-based battery storage equipment.
Products that are covered in this guide include battery storage equipment with a rated capacity of equal to or greater than 1kWh and up to and including 200kWh of energy storage capacity when measured at 0.1C.
The guide includes suggested safety requirements for:
- battery modules (BM) - one or more cells linked together for use in other equipment
- pre-assembled battery systems (BS) - a complete package for connection to a DC bus or DC input of power conversion equipment (PCE)
- pre-assembled integrated battery energy storage systems (BESS) - a complete package that has AC output for connection to the electrical installation.