On a still, sub-zero evening in July, a Gungahlin renter named Aroha switches on an electric heater and half-listens to the ABC weather cross to a graphic she has seen dozens of times: Canberra, "100% renewable electricity" since 2020, the first Australian city to get there. It is repeated so often locally that it has become civic furniture, a fact residents cite the way Melburnians cite four seasons in a day. What the graphic does not show is that on a windless winter evening, the wind farms the territory has under contract — most of them hundreds of kilometres away in New South Wales, Victoria and South Australia — may be turning slowly or not at all, and the electrons actually filling Aroha's power point at that moment come off whatever mix of coal, gas, hydro and renewables happens to be running on the shared eastern grid at 6pm. The territory's claim and the reality flowing into her townhouse are both true. They are simply not describing the same thing.
Aroha's bill also carries a small, separate charge for the scheme that makes the 100% figure possible — a line most Canberrans have never looked at closely, and one the government's own reporting shows has been rising even as the annual ledger says every megawatt-hour used across the territory is matched. Untangling what "100% renewable" legally and financially means, what it genuinely achieved, and what it costs, is the subject of this piece.
What the government did
The ACT's target was built in stages, across three pieces of ACT law. The Climate Change and Greenhouse Gas Reduction Act 2010 (ACT), notified 4 November 2010, set the territory's overarching goal of net zero emissions by 30 June 2045 and flagged 100% renewable electricity by 2020 as an interim milestone (ACT Legislation Register, Act 2010-41). The Electricity Feed-in (Large-scale Renewable Energy Generation) Act 2011 (ACT) then created the delivery mechanism: a government-run reverse auction, under which wind and solar developers bid a fixed long-term price and the ACT contracted with the lowest bidders (ACT Legislation Register, Act 2011-56). The Climate Change and Greenhouse Gas Reduction (Renewable Electricity Target) Amendment Act 2019 (ACT), notified 14 June 2019, then locked the 100% figure into the principal Act ahead of the deadline (ACT Legislation Register, Act 2019-19). On 1 January 2020, the ACT government and independent energy media reported the target met: the territory had contracted renewable generation equal to 100% of its annual electricity consumption, making it the first Australian jurisdiction — and one of a small number of jurisdictions worldwide — to reach that position (ACT Government/RenewEconomy, reporting, Jan-2020).
Between 2012 and 2020 the ACT ran five reverse auctions, contracting roughly 840 megawatts of wind and solar capacity by around mid-2021 — sited not in the ACT, which has little available land for utility-scale wind or solar, but across the wider National Electricity Market in New South Wales, Victoria and South Australia (ACT Government/Climate Choices, reverse-auction records, data to approx. Jun-2021). The contracts run as "contracts for difference": Evoenergy, the ACT's electricity distributor, pays each generator the gap between its contracted strike price and the wholesale spot price whenever wholesale prices sit below that price, and the generator pays the difference back to Evoenergy whenever wholesale prices run above it (Evoenergy/ACT Government, feed-in tariff contract terms, Jul-2020). That two-way structure, rather than a straightforward subsidy, is what let the territory borrow against its own credit rating to bring new wind and solar capacity onto the grid years before it would otherwise have been built.
The strongest case
A financing mechanism that actually built things, and a genuine climate achievement
Credit is due here, and it should not be waved away by the accounting critique that follows. The ACT was the first Australian jurisdiction to reach a fully contracted 100% renewable electricity position, and it got there through a real financing mechanism rather than a marketing campaign: five competitive reverse auctions that used the territory's creditworthiness to underwrite roughly 840 megawatts of wind and solar capacity that would not otherwise have been built on that timetable (Climate Choices, ACT Government, auction records). Because the contracts are two-way — generators must hand back the surplus when wholesale prices run above the contracted price — the scheme is a hedge rather than a one-way subsidy tap; it returned savings to ACT network tariffs during the high wholesale prices of 2022 and cost more again once wholesale prices fell (ICRC, retail electricity price determinations, 2022–2025; Energy Action, commentary on contract-for-difference cost pass-through). The design pre-dated, and was later echoed by, the much larger contract-for-difference schemes New South Wales and the Commonwealth built for their own renewable rollouts. And under national greenhouse accounting, zeroing out electricity emissions was not a token gesture: electricity and gas together made up around 65% of the ACT's total emissions before 2020, so the achievement genuinely reshaped the territory's emissions profile, freeing policy attention to move to the harder remaining sources — transport and gas (ACT Greenhouse Gas Emissions Inventory Reports, approx., pre-2020 baseline).
The evidence
The 100% figure is an annual, territory-wide accounting match, not a real-time or location-specific guarantee. Each year, Climate Choices — the ACT government's climate program — totals the electricity used across the territory and confirms that contracted renewable generation, wherever on the shared grid it physically occurred, was at least equal to that total (Climate Choices, ACT Government, large-scale feed-in tariff reporting). The ACT sits inside the New South Wales region of the National Electricity Market and draws its physical supply through the same shared high-voltage transmission network as the rest of that region. There is no dedicated wire carrying wind-farm electrons directly into Canberra, and there cannot be one, because an alternating-current grid does not route electricity by customer or by contract — it delivers whatever is being generated, from whichever source is running, to whoever is drawing power from the network at that instant.
By the numbers, the gap between the accounted position and the physical one is not small. Coal supplied more than 56% of all generation in the New South Wales region of the National Electricity Market in 2024, with gas, hydro and renewables making up the balance (DCCEEW/AEMO, Australian Energy Statistics, fuel mix by region, calendar year 2024 (approx.)). On a Canberra winter evening, when household heating demand peaks and wind output across the contracted portfolio can fall close to zero, the electrons actually reaching ACT homes are drawn overwhelmingly from that same coal- and gas-heavy regional mix — not from the wind and solar farms the territory pays for under contract.
Accounting versus physics
None of this makes the 100% claim false. Matching annual consumption to contracted renewable output is the same method corporations use when they claim "100% renewable" under schemes like RE100, and it is the standard the National Greenhouse and Energy Reporting scheme recognises for calculating an entity's or jurisdiction's Scope 2 emissions. The method is legitimate. The problem is presentation: the ACT government's own public messaging, and the local media coverage it generates, has consistently used language — "100% renewable electricity", "powered by wind and sun" — that most residents reasonably read as a physical description of their power supply, not as a statement about an annual financial ledger. Surveys are not needed to establish the gap; it is visible every time a grid-stress warning from the Australian Energy Market Operator during a still winter evening is met with confusion from residents who believed the coal and gas fleet no longer mattered to them.
The critique is not confined to activists. In 2020, businessman and prominent renewables sceptic Dick Smith publicly called the ACT's claim "fraudulent", arguing the accounting framing obscured the territory's continued physical reliance on the same fossil-fuel-heavy grid as its neighbours — a characterisation the ACT government rejected, but one that captured a real public confusion about what the 100% figure actually measures (The Canberra Times, reported comments, 2020). Whatever one makes of the word "fraudulent", the underlying observation is accurate and sourced: the claim is a statement about contracts and certificates, not about the physical composition of the electricity in any Canberra power point at any given time.
The territory's electricity meter and its climate ledger tell two different, equally true stories — and only one of them is what most Canberrans think "100% renewable" means.
The cost to ratepayers
The scheme that produces the 100% figure is not free, and its cost has moved in a direction that undercuts the simplest version of the government's pitch. In its 2014-15 price decision, the ICRC forecast the large-scale feed-in tariff scheme would add $3.11 per megawatt-hour to regulated retail tariffs, equivalent to about $23.14 a year, or roughly 44.5 cents a week, on an average four-person household's bill (ICRC, Regulated Retail Electricity Prices 2014-15, Final Report). A decade later, in its 2024-25 retail price recalibration, the ICRC allowed a scheme cost pass-through of $4.86 per megawatt-hour, equivalent to about $31.59 a year for an average household using 6,500 kilowatt-hours (ICRC, Retail Electricity Price Recalibration 2024-25 (approx.)). The rise is not simply inflation: because the contracts are struck at fixed prices, the top-up payments to generators grow precisely when wholesale electricity prices fall, which is the opposite of what a household budgeting around "cheaper renewables" would expect (ICRC price determinations, 2022–2025; Energy Action, commentary on the mechanism, approx. 2024–2025).
There is a transparency gap alongside the cost. The ACT government's own Climate Choices website publishes the underlying data only as raw quarterly Evoenergy spreadsheets, each tens of megabytes in size, with no simple published running total of what the scheme has cost ACT electricity users since the first auction in 2012 (Climate Choices, ACT Government, large-scale feed-in tariff payments and costs). A resident who wants to know what "100% renewable" has actually cost them personally over more than a decade cannot get that answer from the government's own primary disclosure in less than an afternoon of spreadsheet work — a modest but real accountability shortfall for a scheme regularly cited as one of the territory's flagship policy achievements.
The risk to the future
A first-mover claim that ages, on a ledger the public was never taught to read
Two risks compound. The first is that the ACT's advantage on this claim is shrinking: New South Wales and the Commonwealth have since built larger versions of the same contract-for-difference model to underwrite renewable generation across the whole NEM, meaning "first jurisdiction to 100%" becomes a smaller distinction each year even as ACT ratepayers keep paying the scheme's top-up costs (ICRC price determinations; NSW/Commonwealth CfD scheme announcements, various). The second is a trust risk. Electricity was always the easiest 65% of the ACT's emissions to solve, because it could be bought under contract; transport and gas, now the larger remaining shares of the territory's emissions on the way to net zero by 2045, cannot be solved by a reverse auction and certificate match — they require behaviour change the accounting trick cannot deliver (ACT Greenhouse Gas Emissions Inventory Reports, approx.). If a serious grid-stress event coincides publicly with a low-wind evening — the kind AEMO already flags most winters — the gap between the "100% renewable" headline and the coal- and gas-heavy reality on the wire becomes visible all at once, at exactly the moment the government needs public trust in its harder, unfinished climate targets the most.