Methodology

How we calculate your costs

Transparency builds trust. Here is exactly how energy·saver estimates your electricity and gas costs.

Data Source

All electricity and gas plan data is sourced directly from the Australian Energy Regulator’s Consumer Data Right (CDR) Product Reference Data API. This is the same data that every licensed retailer is legally required to publish.

Plans are refreshed automatically every day at 04:00 AEST. Our database currently contains 7,800+ electricity plans and 2,300+ gas plans across NSW, VIC, QLD, SA, and TAS.

Precision Tiers

energy·saver uses a progressive accuracy model. You always see results — more information just makes the estimate more precise.

📊 Tier 0 — Postcode Only±30-40%

Uses 2020 Frontier Economics benchmark usage for your distribution area. The Frontier study surveyed 6,465+ Australian households and remains the most recent official benchmark (the AEMC discontinued updates in August 2023).

📊 Tier 1 — Household Profile±20-30%

Refines the benchmark based on your household size (1-5+ people), home type, and distribution area. Benchmark data from Frontier Economics 2020, broken down by city and household size.

📊 Tier 2 — Appliance Model±15-20%

Adjusts the benchmark for your specific appliances: solar panels, air conditioning type, hot water system, pool pump, EV charging, and gas connection. Each appliance adds or subtracts a fixed kWh amount from the baseline.

Tier 3 — Bill Data±5-10%

Uses your actual kWh consumption from a recent bill, seasonally adjusted to produce an annual estimate. If you provide TOU breakdown or controlled load figures, these replace our default assumptions.

Electricity Cost Formula

Annual Cost = Supply Charge + Usage Charge + Controlled Load − Solar Credit − Discounts
Supply Chargesupply_cents_per_day × 365 ÷ 100
Usage (Flat)usage_cents_per_kwh × annual_kWh ÷ 100
Usage (TOU)Σ (rate × kWh × split_ratio) for peak + offpeak + shoulder
Controlled Loadcl_cents_per_kwh × cl_kWh ÷ 100 (+ CL supply if applicable)
Solar Creditexport_kWh × FiT_cents ÷ 100

All rates include GST as per CDR data standards. All calculations use the plan’s published rates without modification.

Time of Use (TOU) Split Ratios

For TOU plans where you haven’t provided your actual peak/offpeak breakdown, we use the split ratios published in the AER DMO 7 Determination (July 2025) and the ESC VDO 2025-26 final decision. These ratios represent the typical residential consumption pattern in each distribution zone.

DistributorPeakShoulderOff-PeakSource
Ausgrid (EA025)21%79%DMO 7
Endeavour (N705)25%24%51%DMO 7
Essential (BLNT3AU)18%30%52%DMO 7
VIC all (2-period)33%67%VDO 25-26
VIC all (3-period)33%42%25%VDO 25-26
Energex (8900)16%56%27%DMO 7
SAPN (RTOU)53%22%25%DMO 7
TasNetworks (93)52%48%DMO 7
TOU cost estimates use the AER DMO 7 and ESC VDO 2025-26 published peak/offpeak/shoulder usage split ratios. These splits represent a typical residential user in your distribution area. Your actual usage pattern may differ.

Solar Estimation

Solar generation is estimated using Clean Energy Council (CEC) reference yields:

NSW: 3.9 kWh/kW/dayVIC: 3.6 kWh/kW/dayQLD: 4.2 kWh/kW/daySA: 4.2 kWh/kW/dayTAS: 3.5 kWh/kW/day
Annual Generation = System kW × Daily Yield × 365
Self-consumption = 40% (without battery) or 70% (with battery)
Export = Generation − Self-consumption
Solar Credit = Export kWh × Feed-in Tariff rate

Gas Calculation

Gas plans may use single-rate or block pricing. For block pricing:

Annual Cost = Supply × 365 + Block 1 Cost + Block 2 Cost + Block 3 Cost − Discounts

Gas benchmark consumption comes from Frontier Economics 2020 state averages, adjusted for your gas appliance selections (removing ~40% if no gas heating, ~25% if no gas hot water, ~10% if no gas cooking).

DMO/VDO Reference Price Comparison

The percentage comparison against the reference price (DMO or VDO) is calculated using the AER’s model usage — not your actual or estimated usage. This ensures all plans are compared on a like-for-like basis as required by law.

Comparison % = (Reference Price − Unconditional Price at Model Usage) ÷ Reference Price × 100

The unconditional price includes only guaranteed discounts. Conditional discounts (e.g., pay on time) are shown separately and always described as “X% of the reference price” rather than as a percentage of the retailer’s own price.

Data Freshness

Plan data is updated daily at 04:00 AEST from government-regulated energy data. Each API response includes adata_updated_at timestamp so you can verify the data’s age.

Limitations

Our estimates have known limitations: benchmark usage data is from 2020 and may not reflect current trends (e.g., increased EV adoption, heat pump uptake). TOU splits are based on average profiles, not your individual usage pattern. We do not currently factor in demand tariffs or seasonal rate variations. Solar yield estimates use state-level averages and do not account for roof orientation, shading, or panel degradation.

For the most accurate comparison, upload your most recent electricity bill (Tier 3). Always confirm pricing with your chosen retailer before switching.

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