A community battery, also sometimes referred to as a ‘neighbourhood battery’, is a particular scale of battery storage. These types of batteries come in many shapes and sizes and can serve many purposes.

These batteries are bigger than a home battery. A typical household battery (often used to store rooftop solar energy) might have a storage capacity of up to about 10 kilowatt-hours (kWh). This might be enough to power your average household for a day. On the other hand, community batteries range from ~40kWh to 20 megawatt-hours (MWh) in capacity.

Community batteries can be connected ‘in front of the meter’ to the electricity network; that is, they are located outside of your home or property and connected to the local network as a standalone unit. A community battery would typically be located at the street level close to where electricity is being consumed and generated.

Community batteries can also be connected 'behind the meter', similar to a household battery, and can be setup to charge from rooftop solar on the same property. Depending on how the battery operates, it can be used to provide backup power.

Community batteries can be owned by electricity distribution businesses or third parties such as community energy groups, electricity retailers, and private investors. Many batteries trade electricity by buying and selling from the market, and therefore, many batteries (especially if they are larger), will be operated in a way to generate revenue. The owner and operator of the batteries can be the same or separate parties.

• Reduces solar waste. Solar PV generates most of its energy during the middle of the day when the sun is shining, but when electricity is often in lowest demand. By absorbing excess solar energy that is generated during the day and exported to the grid, the battery makes this energy available for the evening peak, and makes use of energy which would otherwise be wasted.
• Allows more solar installations. Community batteries enable the network to support more rooftop solar by time-shifting solar energy generated during the day and discharging it during the evening peak demand period. By easing solar congestion on the local transformer (an asset of the network which transforms energy into the voltage required by households), the electricity grid can handle more incoming solar installations.
• Network support: By providing services which help to manage electricity congestion in the network, DNSPs (distribution network service providers) can defer the need to make costly network upgrades. By upgrading the network and lowing costs of network maintenance, community batteries put downward pressure on electricity costs.
• Market services: Community batteries can participate in spot price arbitrage (buying electricity when prices are lower and selling when they are higher) in the wholesale electricity market, which can help to manage the grid and put downward pressure on electricity prices for everyone. They can also provide services which help maintain the security and reliability of the electricity system and reduce the risk of blackouts.
• Backup power: If designed and installed in a certain way, these batteries can in some cases provide backup power to a building or electricity network.
• Community batteries also have many other intangible benefits such as the fostering of community, placemaking, civic pride, and promoting education about energy and equity.

These batteries can be sized in a variety of ways, ranging in capacity from ~40 kilowatt-hours (kWh) to twenty megawatt-hours (MWh). YEF’s Fitzroy North community battery, for example, has a storage capacity of 309kWh and connects to the low-voltage distribution network which shares connections with approximately 200 homes.

For a front-of-meter system, like our Fitzroy North battery, excess solar energy that is exported to the local network by local properties is absorbed by the battery as it charges from the same local network. This energy is then discharged during times of peak demand – usually in the evening. When little or no locally generated solar is available (for example, on cloudy days), the battery charges from the grid. Typically, this electricity has fewer associated carbon emissions since more renewable energy is generated across the grid during the day (for example, by remote wind or solar farms). The battery itself uses lithium-ion technology, the industry standard form of electricity storage for batteries. This is the same technology used for smartphone batteries and electric vehicles. Read about the battery hardware here.

Community batteries generally make some noise, and the noise level will depend on the type of technology, its size, how it operates, and the environment in which it sits. For example, our Fitzroy North battery makes some noise when it is charging and discharging (the sound of the converters). This occurs during the day when the sun shines and in the evening, especially during peak demand, but is very quiet at night. It also has a hum from the air conditioners needed to keep the battery modules within a certain temperature range.

As a reference, the Fitzory North battery noise level is very low. Generally speaking, a community battery could range from about 50-70 decibels at 1 metre from the unit. 50 dB can be equated to the sound of a conversation at home, and 70 dB can be equated to a vacuum cleaner. Note that 50 dB is only 25% as loud as 70 dB because dBA is on a logarithmic scale.

Noise levels do depend on battery model and size, and whether sound is an issue in practice will depend on:

• Sound treatment within the battery cabinet itself (noise can be managed by installing acoustic panels within or outside of the battery unit)
• Which direction the battery is facing (where is sound projecting and how might it reflect off surfaces)
• The natural acoustic properties of the in situ environment (e.g., is it concrete, grass, vegetation, brick walls, or open space)
• Any environmental sound treatment or insulation as part of the installation
• The distance from the battery to nearby properties (and how sound will degrade over that distance
• Any competing ambient sounds (like traffic in the distance) that would drown out the sound of the battery.

For the Fitzroy North Community Battery, the installation design was co-created by YEF, the local community, and the battery supplier Pixii. Together, we ensured that noise is not an issue for local residents, even those living closest to the battery. At the time of procurement, we assessed the PowerShaper as one of the best battery systems for inner-urban residential environments.

Yes, the batteries that YEF has installed are safe. Our selection of suppliers and our testing of their technology follow a rigorous process to ensure that they operate safely and do not pose a fire threat, and operate within Australian standards for Electro-Magnetic Fields (EMF).

For the Fitzroy North community battery, YEF worked with a team of engineers from CitiPower (the network distributor), Pixii (the battery supplier), and Ventia (the installer), to ensure safe installation of the battery.

They can help suburbs to become ‘EV-ready’ and this is likely to be a key consideration for future community battery rollouts. YEF is investigating the addition of a co-located EV charger for another community battery slated for installation at Collingwood Leisure Centre, as part of Round 2 of the Victorian Government’s Neighbourhood Battery Initiative.

The battery selected for the Fitzroy North community battery, the Pixii PowerShaper, is by far the most sustainable battery model from a lifecycle analysis point of view out of more than a dozen options evaluated through an exhaustive assessment and evaluation process. The battery module manufacturers, Polarium, are the first in the world to announce manufacturing of battery modules made with 100% renewable energy, and up to 95% of the physical materials used in the PowerShaper are recyclable. Read more about the battery selection.

They can, however, it is up to the embedded network operator to initiate the process for embedded network customers. If the community battery was installed outside the embedded network, the embedded network operator could benefit and could pass on the benefit to all of their customers. Communities and developers should engage early in new developments to explore how future communities could benefit from community batteries.