Electricity Tariff Optimisation in Australia: Understanding Network Charges, TOU, and Demand Pricing

If you manage electricity costs across a commercial portfolio, you already know the bill is more complicated than a simple cents-per-kilowatt-hour number. Network charges alone account for 40–50% of a typical Australian electricity bill, yet most businesses treat them as a fixed, unavoidable cost.

They are not.

With network tariff reform accelerating across the National Electricity Market (NEM) — including the AEMC's landmark pricing review currently underway — the structure of what you pay is shifting. Legacy flat-rate tariffs are being retired. Time-of-use and demand-based pricing are becoming the default. And for businesses that understand these changes, there is a genuine opportunity to reduce costs without reducing consumption.

This guide breaks down the three pillars of commercial electricity pricing in Australia — Network Use of System (NUOS) charges, time-of-use (TOU) tariffs, and demand pricing — and provides a practical framework for optimising each.

What Are NUOS Charges and Why Do They Matter?

NUOS (Network Use of System) charges are what you pay for the physical infrastructure that delivers electricity to your premises — the poles, wires, substations, and transformers that make up Australia's distribution and transmission networks.

Every commercial electricity bill in the NEM includes NUOS charges, approved annually by the Australian Energy Regulator (AER) [3]. They are not negotiable in the way wholesale energy rates are, but the tariff structure you sit on determines how those charges are calculated — and that is where optimisation begins.

The Components of NUOS

NUOS charges are made up of several distinct components:

Distribution Use of System (DUoS) is the largest component, covering the cost of the local distribution network that delivers electricity from the transmission system to your site. DUoS charges vary significantly by distributor, voltage level, and tariff class.

Transmission Use of System (TUoS) covers the high-voltage transmission network that moves electricity from generators to distribution networks. TUoS is typically a smaller proportion of the total NUOS charge but still varies by location and load profile.

Metering charges cover the cost of your meter infrastructure, including data services, maintenance, and capital recovery. With the rollout of smart meters accelerating, metering charges are evolving.

Jurisdictional scheme amounts are regulatory pass-through costs that fund state-specific programs, including energy efficiency schemes and renewable energy targets.

The critical insight is this: NUOS charges are not applied uniformly. The tariff class your site is assigned to — and the pricing structure within that class — determines whether you pay a flat volumetric rate, a time-of-use rate, a demand-based charge, or some combination of all three.

Time-of-Use (TOU) Pricing: When You Consume Matters

Time-of-use tariffs divide the day into pricing windows — typically peak, shoulder, and off-peak — with different rates for each period. The principle is straightforward: electricity delivered during periods of high network demand costs more to supply, so the tariff reflects that.

For commercial customers in the NEM, TOU tariffs are rapidly becoming the default. As of July 2025, legacy flat-rate tariffs have been retired or are being phased out across most distribution networks in New South Wales, Victoria, Queensland, South Australia, and Tasmania.

What the 2025–26 Tariff Changes Mean in Practice

The changes are significant and state-specific:

In New South Wales, Ausgrid, Endeavour Energy, and Essential Energy have transitioned large low-voltage customers consuming over 160 MWh annually to the new "Large Time of Use Demand and Energy" tariff [4]. Legacy flat-rate and transitional demand tariffs have been phased out, with network charge increases averaging approximately 5.8% [5].

In Victoria, AusNet Services, CitiPower, Jemena, Powercor, and United Energy have implemented cost-reflective TOU and demand-based structures, including dynamic tariffs for customers with flexible consumption patterns [6].

In Queensland, Energex and Ergon Energy have introduced new default tariffs emphasising time-of-use and demand charges, with evening peak demand users facing higher charges and daytime shifters benefiting from lower rates [6].

South Australia and Tasmania have followed similar paths, with SA Power Networks and TasNetworks retiring non-cost-reflective tariffs and introducing structures that reward off-peak and solar-aligned consumption.

The Optimisation Opportunity

TOU tariffs create a direct incentive to shift discretionary load away from peak windows. For commercial sites, this might mean rescheduling HVAC pre-cooling cycles, adjusting EV charging schedules, or timing battery storage dispatch to shave peak network demand.

The key is visibility. Without granular interval data — ideally at 5-minute or 15-minute resolution — it is impossible to know whether your consumption profile aligns with or works against your tariff structure. Most businesses simply do not have this visibility, which means they are paying more than they need to.

Demand Charges: Your Peak Defines Your Cost

Demand charges are the most misunderstood component of commercial electricity pricing — and often the most expensive.

Unlike volumetric charges (which bill you for total energy consumed), demand charges bill you for your highest rate of consumption during a defined measurement window. A single 30-minute spike in demand during a peak period can set your demand charge for the entire billing cycle.

For large commercial and industrial customers, demand charges can represent 30–40% of total network costs. Yet many businesses have never analysed their demand profile or understood how it drives their bill.

How Demand Charges Are Calculated

Most NEM distributors calculate demand charges based on the maximum demand (measured in kVA or kW) recorded during a specific time window — typically the peak TOU period. The charge is applied as a rate per unit of maximum demand, multiplied across the billing period.

This means a facility that draws 500 kW consistently pays less in demand charges than one that normally draws 200 kW but spikes to 800 kW during a single half-hour period. The spike sets the charge.

Network Demand Charges in Practice: Three Examples Worth Knowing

The complexity of demand charges becomes clearer when you look at how individual networks implement them. These are not edge cases — they represent the kind of tariff structures that energy consultants and portfolio managers encounter daily.

AusNet's Critical Peak Demand (CPD) Program — Victoria

AusNet Services operates a Critical Peak Demand tariff for business customers consuming more than 160 MWh annually [7]. Rather than applying a flat demand charge year-round, AusNet's CPD structure ties demand charges to the network's actual stress periods — predominantly summer afternoons when air conditioning drives peak load across Melbourne's distribution network. Customers on CPD tariffs can participate in AusNet's GoodGrid program, which rewards businesses that reduce consumption during declared peak events with lower demand charges. The incentive is significant: a site that successfully curtails load during the handful of critical summer peaks can materially reduce its annual network cost. With AusNet forecasting maximum demand growth of 13% during summer and 18% during winter across the 2026–31 regulatory period [7], CPD tariff structures are only going to become more prominent.

Ausgrid's Seasonal Demand Windows — New South Wales

Ausgrid takes a different approach by applying demand charges only during defined seasonal windows. Between November and March (summer) and June to August (winter), demand charges apply based on the highest 30-minute consumption block during peak hours (3pm–9pm for small business, working weekdays) [4]. During the shoulder months of April, May, September, and October, no demand charges apply at all — these months are classified entirely as off-peak. Ausgrid also operates a Critical Peak Pricing mechanism for customers on network storage tariffs, where the distributor can declare up to 40 hours of critical peak events per financial year, with at least 24 hours' notice provided to retailers [4]. For businesses that can respond to these signals, the cost difference between a reactive and proactive approach is substantial.

Western Power's Contracted Maximum Demand — Western Australia

Western Australia operates outside the NEM under its own regulatory framework (the Wholesale Electricity Market), and Western Power's tariff structures reflect this. The network offers a range of reference tariffs from simple anytime energy (RT2) through to sophisticated multi-part time-of-use demand structures. RT7 and RT8 are Contract Maximum Demand tariffs for high-voltage and low-voltage customers respectively, where businesses nominate a contracted demand level (CMD) and pay capacity charges based on that commitment. Exceed your contracted demand, and the Excess Network Usage Charge (ENUC) applies — a penalty rate on the difference between your actual peak and your nominated DSOC (Declared Short-term Operating Capacity). Western Power has also introduced new tariffs including RT20 (three-part TOU demand) and RT22 (multi-part TOU with five time periods including overnight and super off-peak windows) [8], reflecting a push toward more granular, cost-reflective pricing. For consultants managing portfolios that span both NEM and WA sites, the regulatory and structural differences between these systems add a genuine layer of complexity.

Practical Demand Management Strategies

Effective demand management requires a combination of monitoring, analysis, and operational response:

Load staggering involves sequencing the start-up of major equipment to avoid simultaneous peak draws. This is particularly relevant for sites with chillers, compressors, or large HVAC systems that draw heavily during morning start-up.

Battery storage dispatch can shave demand peaks by discharging stored energy during high-demand periods, reducing the maximum demand recorded by the meter.

Demand response programs offered by some retailers and network operators provide financial incentives for reducing demand during critical peak events.

Real-time monitoring and alerting enables facility managers to respond to demand events as they happen, rather than discovering them on the next bill.

The AEMC Pricing Review: What Is Changing

The Australian Energy Market Commission (AEMC) is currently conducting a landmark review of electricity pricing — "Electricity Pricing for a Consumer-Driven Future" — with a final report expected in June 2026.

The draft report, published in December 2025 [9], proposes a comprehensive package of reforms to be implemented over approximately 10 years. The core recommendation is a shift toward higher fixed network charges and lower volumetric rates, designed to reflect the true cost of maintaining the grid as distributed energy resources (solar, batteries, EVs) reshape consumption patterns.

For commercial customers, the implications are significant. If fixed charges increase and volumetric rates decrease, the economic case for demand management and load shifting changes. Businesses with high but consistent consumption may benefit, while those with lower consumption but high peak demand may face increased costs.

The reform is not yet finalised — stakeholder submissions closed in February 2026 [10], and the final recommendations will shape network pricing rules for the next decade. But the direction is clear: tariff structures are becoming more complex, more cost-reflective, and more dependent on when and how you consume, not just how much.

A Framework for Tariff Optimisation

Optimising your electricity tariffs is not a one-off exercise. It requires ongoing visibility, analysis, and action across four dimensions:

1. Tariff Assignment Review

Start by confirming which tariff class each site is assigned to. Distributors periodically reassign customers based on consumption thresholds, and a site that has crossed a threshold may be eligible for a more favourable tariff. This is particularly relevant following the July 2025 tariff restructures.

2. Interval Data Analysis

Analyse your consumption at interval level (5-minute or 15-minute data) against your current tariff structure. Identify where peak consumption overlaps with peak pricing, and quantify the cost of demand spikes versus steady-state consumption.

3. Load Profile Optimisation

Develop operational strategies to shift discretionary load away from peak windows and reduce demand peaks. This may involve equipment scheduling, battery dispatch, or demand response participation.

4. Ongoing Monitoring and Validation

Tariff structures change annually. Network charges are approved each July, and the AEMC reforms will introduce further changes over the coming decade. Continuous monitoring ensures you are always on the most favourable tariff and that your consumption profile is optimised against it.

How Utilified Supports Tariff Optimisation

Utilified's Utility Management System (UMS) is purpose-built for exactly this kind of analysis. The platform collects interval meter data across electricity, gas, water, and LPG — processing over 420,000 intervals per meter annually — and maps it against Australian-specific tariff structures.

UMS maintains a comprehensive database of network tariffs across all NEM distributors — and Western Power in WA — enabling automated tariff comparison and assignment validation. Critically, the platform handles the full complexity of Australian tariff structures natively: AusNet's Critical Peak Demand calculations, Ausgrid's seasonal demand windows and critical peak events, Western Power's contracted maximum demand and ENUC charges, and the dozens of other distributor-specific structures that make manual tariff analysis so time-consuming.

Combined with Utiliread's automated invoice extraction and validation engine, the platform identifies billing errors, tariff misalignments, and optimisation opportunities that would take weeks to uncover manually.

For energy consultants managing multi-site portfolios — particularly those spanning NEM and WA networks with different regulatory frameworks — this transforms tariff optimisation from a manual, spreadsheet-driven process into an automated, scalable capability. One platform, every tariff structure, clear ROI for every client in the portfolio.

Explore tariff optimisation tools in UMS →

Key Takeaways

• Network charges account for 40–50% of commercial electricity bills, yet most businesses never analyse or optimise them.
• Time-of-use tariffs are now the default across the NEM, creating direct incentives for load shifting.
• Demand charges are driven by peak consumption, not total consumption — a single spike can define your cost for the entire billing cycle.
• The AEMC pricing review will reshape tariff structures over the next decade, with a shift toward higher fixed charges.
• Effective tariff optimisation requires interval data visibility, ongoing monitoring, and a platform that understands Australian tariff structures.

References

[1] Australian Energy Regulator, Pricing Proposals and Tariff Variations — Network charges (NUOS) typically comprise 40–50% of a commercial electricity bill. AER Pricing Proposals

[2] Australian Energy Market Commission, The Pricing Review: Electricity Pricing for a Consumer-Driven Future. AEMC Pricing Review

[3] Australian Energy Regulator, Network Tariff Reform. AER Network Tariff Reform

[4] Ausgrid, ES7 Network Price Guide July 2025. Ausgrid Network Price Guide

[5] Essential Energy, 2025–26 Annual Pricing Proposal Overview. Essential Energy Pricing Proposal

[6] Austech Power & Gas, Navigating the 2025/26 Electricity Network Tariff Changes for Large Business Customers. Austech Tariff Changes

[7] AusNet Services, Electricity Distribution Price Review 2026–31 and GoodGrid CPD Program. AusNet EDPR 2026–31 | GoodGrid CPD Program

[8] Economic Regulation Authority Western Australia, ERA-Approved 2025–26 Price List for the Western Power Network. ERA Price List

[9] Australian Energy Market Commission, Pricing Review Draft Report, December 2025. AEMC Draft Report

[10] Australian Energy Regulator, Submission to AEMC Pricing Review. AER Submission