Why Australian electricity prices change

Household electricity prices in Australia do not move because a single person in a capital city decides they should. They move because four cost layers move, often in opposite directions, and because two safety-net instruments — the Default Market Offer and the Victorian Default Offer — are rebuilt every year. Understanding the stack will not make the bill pleasant. It will stop you blaming the wrong layer, and it will tell you whether a switch is likely to help.

The layers are wholesale energy, networks, environmental policies, and retail. On a typical household bill, networks are about 40 to 50 per cent. Wholesale is a large, volatile slice. Environmental schemes are smaller but visible. Retail operating costs and margin are the rest. Solar exports and concessions then adjust what you actually pay. None of these percentages is a law of nature. A frugal apartment on a high supply charge is mostly network and retail. A big house with a pool is more exposed to wholesale and to usage rates.

Wholesale: the part that swings

Generators sell electricity into a regional spot market (on the east coast, the National Electricity Market). The price in New South Wales is not the price in Victoria or South Australia. It changes every five minutes. A still, hot late afternoon — coal units offline, gas peaking, rooftop solar fading — can print a very high spot price. A mild sunny Sunday can print a very low one, even negative.

Retailers do not generally pass you the five-minute price. They hedge. They buy futures, they sign offtake contracts with wind and solar farms, they own generation. The quality of that hedging shows up a year later in the usage rate on your fact sheet. When hedges were struck in a tight market, next July is expensive. When a windy, sunny year crashed forward prices, the DMO and VDO can fall even if your local coal station is still in the news.

Wholesale is also why time-of-use and Solar Sharer products exist. The grid's cheap hours have shifted toward the middle of the day. Night is no longer the only trough. That is a price signal from the wholesale layer, dressed up as a retail plan. It is not a moral judgement about when you cook.

Fuel costs still matter. Gas-fired peakers set the price in many tight intervals, so international gas prices leak into east-coast electricity. Coal plant outages leak just as hard. A guide that blames "renewables" or "coal" for every movement is selling a side. The honest version is that the mix, the weather, the outages and the hedge book all show up in the same usage rate. How electricity markets differ across Australian states is the regional map.

Networks: about 40 to 50 per cent of the bill

The distributor (the network business) owns the poles, the wires, the local zone substations and, in most cases, the meters. You do not choose it. The address chooses it. Ausgrid, Endeavour and Essential in New South Wales; Energex in south-east Queensland; SA Power Networks in Adelaide; CitiPower, Powercor, United Energy, Jemena and AusNet in Victoria — each has a revenue allowance set by the Australian Energy Regulator, except where a state regime says otherwise.

Network prices change when:

• the AER approves a new revenue determination (a multi-year decision)
• the distributor reallocates that revenue between residential, business and demand tariffs
• a smart-meter rollout or a bushfire-hardening program is being paid for
• customer numbers or consumption forecasts change, so the same revenue is spread over fewer or more kilowatt hours

That is why a quiet year in wholesale markets does not guarantee a cheaper bill. If the network is recovering more, the supply charge and the usage rate both creep. It is also why two houses 20 kilometres apart can have different standing-offer prices: they sit on different networks. The 2026-27 DMO and VDO figures in the next section are, in large part, network stories wearing a retail label.

You cannot shop the distributor. You can shop the retailer, and you can sometimes shop the network tariff shape — single rate, time-of-use or demand — which changes how that 40 to 50 per cent is recovered from you. Demand tariffs and time-of-use versus single-rate are the consumer-facing end of network pricing.

Transmission, the very high-voltage backbone, sits above the distributor. New interconnectors and Renewable Energy Zone lines are paid for over decades, not in a single July. They matter. They are not why this quarter's bill jumped $40.

Environmental policies

Federal and state schemes add a cost per megawatt hour that retailers recover in the usage rate. The large-scale Renewable Energy Target requires large-scale generation certificates (LGCs). The small-scale scheme creates small-scale technology certificates (STCs) when households install solar. State schemes — energy-efficiency certificates, Victorian Energy Upgrades, New South Wales peak demand reduction — add their own certificates. GreenPower is an extra, voluntary LGC surrender on top.

These costs rise when certificate prices rise, and when the surrender percentage for the year steps up. They fall when certificate markets are well supplied. They are not "the carbon tax" and they are not the whole bill. On most household invoices they are a noticeable minority. Retailers rarely itemise them in a useful way. The DMO and VDO decisions do.

Rooftop solar complicates the politics. Households with panels avoid some usage and some of these scheme costs; they also export energy that depresses daytime wholesale prices for everyone. That transfer is real. It is also the reason midday retail rates are falling in some networks. You can dislike the distributional effect and still use the cheap window.

Retail, and the annual DMO reset

The retailer is the company that sends the bill. It buys wholesale energy, pays the distributor, surrenders certificates, runs a call centre, and adds a margin. Competition is supposed to keep that margin thin. Sometimes it does. Sometimes the household that never switches funds the discounts of the household that does.

Retail prices move because the three layers above moved, and because the retailer changed its discounting strategy. A market offer that was 15 per cent below the reference price can be rebuilt at 6 per cent below once the retailer has enough customers. That is not a network event. It is a retail event. How to compare electricity plans is the defence.

The Default Market Offer and the Victorian Default Offer reset on 1 July. They cap standing offers and they reset the advertising stick for market offers. They are the reason so many letters arrive in the same fortnight. For 2026-27, from 1 July 2026, the AER's residential DMO amounts are:

• Ausgrid: $1,899 at 3,900 kWh, down 3.4 per cent
• Endeavour Energy: $2,328 at 4,900 kWh, down 3.4 per cent
• Essential Energy: $2,604 at 4,600 kWh, down 5 per cent
• Energex (south-east Queensland): $1,988 at 4,600 kWh, down 7.2 per cent
• SA Power Networks: $2,334 at 4,000 kWh, up 1.4 per cent

Victoria's VDO at 4,000 kWh sits at about $1,481 in CitiPower's area and about $1,748 in AusNet's area. Details sit in the Default Market Offer explained and the Victorian Default Offer explained.

The 2026-27 direction of travel

The 2026-27 reset is not a national cut and it is not a national rise. New South Wales and south-east Queensland standing-offer reference prices fall. South Australia edges up. Victorian households still face a wide gap between inner-Melbourne and AusNet networks, because the network layer is different. Western Australia is not on this calendar; that market has its own regulator and its own retailer structure.

What a household should take from the direction of travel:

• A falling DMO is permission to re-compare, not a reason to assume your market offer followed it down.
• A rising South Australian DMO is a reason to check whether you are still on a standing offer you forgot about.
• Solar households should look at evening usage rates and feed-in, not at the DMO percentage on a brochure. Midday wholesale pressure is already showing up in products such as Solar Sharer.
• Concession holders should confirm the rebate still applies after a switch. The price stack moves; the card rules are state-specific.

If your rates rose while the DMO in your network fell, the retailer changed the market offer. That is lawful. It is also a signal to use Energy Made Easy or Victorian Energy Compare again. If your rates fell and your bill did not, look at kilowatt hours, a new demand tariff, or a lost pay-on-time discount before you write to a minister.

Prices will keep moving. Coal plants will retire. Networks will spend. Certificate markets will swing. The useful habit is to know which layer moved, and to shop the only layer you can actually choose: the retail plan, once a year, on your own usage.