Victorian network United Energy is installing two 75kWh pole-mounted batteries in suburbs about 20km south-east of Melbourne’s CBD for communities to share the benefits of solar and storage. The solution will make the most of surplus solar that is exported to the grid around midday, when voltage levels can rise on feeder lines where PV is popular with homeowners.

The company says pole-mounted batteries on its low-voltage network will support up to 150 homes and businesses with stored energy. Two locations selected for the trial are Gordon Crescent in Black Rock and Telford Street in Highett. The locations were selected based on residential density, electricity demand, noise concerns and with best efforts to keep things out of sight.

United reckons the number of its customers with rooftop solar will more than double in the next five years. However, storage is still too expensive for the majority of homeowners with PV installations.

“If the trial is successful, we may incorporate these batteries in other parts of our network to keep network charges low for customers and support us to continue delivering reliable power,” said United Energy general manager, electricity networks Mark Clarke.

Both test locations are in areas where there are constraints on the network, United said in a statement. “This means that on peak demand days there is a risk of outages because the network cannot physically move enough electricity to meet customer needs.”

Batteries, it hopes, will help sustain reliable supplies while deferring network investment.

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The batteries will charge when there is low electricity demand from the network or when rooftop PV systems are exporting to the grid. Power from the batteries will be deployed later in the day when demand is high and solar systems are no longer generating.

United also expects they’ll also provide essential capacity on extreme heat days, when residential air-conditioner units are often dialled to chill family homes. The batteries each have the capacity to support between 50 and 75 customers for up to 2.5 hours each, the network says.

The two batteries are being installed in February and their performance will be monitored until June. The $500,000 trial is being funded by United Energy and the Australian Energy Regulator’s Demand Management Innovation Allowance.

“This is our investment in developing a flexible network to power customer choices,” United says. “If the trial is successful, we will continue using batteries to support reliability for customers and help keep electricity distribution prices low.”

There are nearly 4,500 solar connections in the Bayside Council area, generating 17,668kWh of electricity. By 2026, this is set to more than double to about 10,000 connections and 46,082kWh.

United Energy spends about $4 million a year to replace and upgrade overloaded distribution substations.

The two-metre-high and one-metre-wide batteries will be installed about five metres up the poles and look similar to other network infrastructure such as transformers.