Community batteries are helping neighbours in Australia share energy – here’s how

Community batteries are being trialled in neighbourhoods across Australia. These help residents pool and share solar energy.

Here’s a short explainer.

Community batteries are energy storage units based in local neighbourhoods.

Residents with solar panels on their homes can use them to store spare electricity they haven’t used. By pooling excess energy from local homes, the community batteries build up a store of electricity for later use. Typically, energy stored during the day when sunlight is plentiful will be released in the afternoon and evenings during peak times when energy demand – and its cost – is higher. This eases pressure on the electricity grid.

Community batteries vary in size and might look like a fridge or a shipping container. A one-megawatt hour (1MWh) battery can power up to 1,000 average homes for about two hours.

In Australia, electricity distributors are trialling community batteries in various neighbourhoods. More than 30% of Australian homes have rooftop solar panels, according to the Australian Government. Solar is the country’s fastest growing type of energy generation and accounted for 10% of Australia’s electricity in 2020-2021.

In Western Australia, an initial trial by state utilities Western Power and Synergy in Alkimos Beach north of Perth involved 119 homes joining a community battery scheme.

Households are typically paid for sending their spare electricity to the community battery, and are then charged a bit less for using energy from it. Australia’s ABC News reports that householders saved about AUS$81,000 on electricity costs over the five years of the trial. They also consumed 85% less energy from Australia’s electricity grid at peak times.

In New South Wales on Australia’s east coast, electricity distributor Ausgrid is running community battery trials in another three areas. Ausgrid says the benefits of community batteries include removing the need for homes to buy their own batteries and keeping electricity prices down for residents and the wider community.

When the sun shines and the wind blows, it can produce plentiful renewable energy – often much more than is needed at the time.

An example is a wind farm producing energy during the night, when demand is typically lower. Wind power that could have supplied more than a million homes was wasted in 2020 because there was nowhere to store it, according to a recent report for UK-based renewable energy company Drax by professional services group KPMG.

Storage tackles this problem. It can provide energy when the sun isn’t shining and the wind isn’t blowing, and can be used at times of high energy demand.

Different types of renewable energy can be stored in different ways. For example, water can be released downhill through turbines to create electricity at times of high demand. This is a type of hydroelectric energy storage known as pumped storage.

Other renewable storage solutions include thermal energy storage. This captures waste heat from buildings and industrial processes and stores it for use later.

By 2040, batteries in homes and businesses will account for 57% of the world’s energy storage capacity, according to the Global Battery Alliance.

This is a collaboration of public and private sector organizations launched at the World Economic Forum in 2017.

One of the Global Battery Alliance’s visions is to use batteries to provide 600 million people with access to electricity. This includes closing the gap between those with and without electricity in sub-Saharan Africa by 70%.

Batteries will also play a big role in reducing the carbon footprint of the power and transport sectors, the alliance predicts. The two sectors currently create about 40% of annual carbon emissions globally.