Canberra Outdoor Power Field

(ABC News: Jake Evans) Only about five per cent of the territory's electricity is generated within its borders, by a few solar farms and rooftop panels on Canberra homes. The rest comes from the national electricity market — the grid that powers the eastern seaboard — and four-fifths of the grid's power comes from non-renewable sources.

With that, the ACT, more than 1,000 kilometres away, will "officially" be powered by 100 per cent renewable electricity. But that does not mean Canberra is some sort of commune running off the grid. Rather, for every watt of power the ACT consumes, it pays one back through its renewable investments around the country.

The Big Canberra Battery project will deliver large-scale batteries across the ACT to ensure that our electricity grid remains stable. Funding: $300 million + The Big Canberra Battery project will deliver large-scale batteries across the ACT to ensure that our electricity grid remains stable.

Those investments, together with Canberra's own solar, put a stop to about 40 per cent of the ACT's carbon emissions, compared to what it would emit if it just bought traditional power from the grid. The ACT-contracted solar and wind farms cover 77 per cent of the capital's electricity consumption.

As the vast majority of the electricity produced on the grid is from non-renewable sources, the power that Canberrans consume at any time may well have been generated by burning coal or gas. ACT Climate Change Minister Shane Rattenbury says the next step is effective storage. (ABC News: Jake Evans)

In line with the contracted awarded via a reverse auction to identify the cheapest sources of renewable electricity, ACT is now purchasing the electricity produced by the Hornsdale Stage 3 wind farm in South Australia. The supply from the 109MW wind farm has now tipped the ACT over the 100% renewable electricity milestone.