Going all-electric in Perth: the full household gas electrification guide

WA gas retail is competitive — multiple retailers serve Perth residential customers (Alinta Energy, Kleenheat, AGL, Origin, ENGIE, and others). But for households with solar, the economics of gas are increasingly challenged by the fixed supply charge ($200–$280/year) and the rising availability of electric alternatives that can use cheap solar generation.

Going fully electric removes the gas supply charge entirely — and lets solar (and cheap Midday Saver electricity) power everything in the home.

The WA gas supply charge

Every Perth household with a gas connection pays a fixed daily supply charge regardless of how much gas they use. At approximately 56–62c/day (varying by retailer), this amounts to $200–$280/year just to have gas connected.

For households with minimal gas use (only gas hot water, gas cooking on a hob used infrequently), the supply charge may exceed the actual energy cost of the gas they use.

Key calculation: If your annual gas bill is $500 and $250 of that is the supply charge, the energy cost is only $250. The supply charge is a fixed tax on the connection — regardless of solar, efficiency, or usage reduction.

Perth's gas electrification landscape

Hot water

Current setup: gas storage or continuous flow (instantaneous) Replacement: heat pump hot water system

Heat pump hot water costs approximately $50–$150/year to run on Midday Saver super off-peak (9am–3pm at 8.85c/kWh). Gas hot water (4-star continuous flow) costs approximately $300–$450/year including gas consumption — and this doesn't include the supply charge.

This is typically the highest-return electrification step. See the heat pump hot water guide for detail.

Timeline to payback:

• Heat pump cost installed: $3,000–$5,000
• Annual running saving (energy + supply charge if gas is only gas appliance): $400–$650/yr
• Payback: 5–8 years, faster if supply charge is eliminated

Space heating

Current setup: ducted gas heating (reverse cycle already used for cooling in Perth) Replacement: reverse cycle AC (also provides heating)

Most Perth homes already use reverse cycle split systems or ducted reverse cycle for cooling. These same systems heat in winter. The majority of Perth homes that heat with gas do so with a ducted gas heater that is separate from the cooling system.

When it makes sense: If the gas ducted heating system is approaching end of life (typically 15–25yr lifespan), replacing it with reverse cycle ducted is the efficient time to electrify. Replacing a fully functional ducted gas heater with electric heating before it fails rarely pencils out financially due to the replacement cost ($8,000–$18,000 for ducted reverse cycle).

If only using gas for heating (no hot water): The supply charge logic applies — eliminating a gas connection that only heats in winter may save $200–$280/yr in supply charge, which is meaningful relative to the modest use.

Perth heating demand is low: Perth winters are mild — heating months are June–August, and many nights don't require heating at all. Gas heating demand in Perth is significantly lower than in Melbourne or Canberra, so the financial case for electrifying space heating (absent appliance replacement timing) is weaker in Perth than southern states.

Cooking

Current setup: gas hob + electric or gas oven Replacement: induction cooktop + electric oven

Induction cooktops are significantly more efficient than gas (approximately 85% efficiency vs 40% for gas hob). For Perth households on solar or Midday Saver, induction cooking during solar hours costs approximately $0.05–$0.15 per cooking session at super off-peak rates.

Upfront cost:

• 60cm induction cooktop: $600–$2,500 depending on quality
• Installation (electrician for dedicated circuit, typically 20A): $300–$700

Annual running cost: Cooking uses approximately 3–5kWh/day for a family. At 8.85c/kWh Midday Saver super off-peak, cooking during the day costs approximately $100–$160/yr. Gas cooking at typical Perth gas rates costs approximately $150–$250/yr including supply charge proportion.

Practical consideration: Some households have strong cooking preferences for gas (responsiveness, flame control) that outweigh the financial argument. This is a legitimate reason to retain gas cooking even when the economics favour electrification.

The full electrification pathway

Priority order (by financial return for typical Perth household with solar):

1. Heat pump hot water — highest single return; eliminates ~50% of gas bill + supply charge if hot water is only gas appliance. Payback ~5–7yr.

2. Cancel gas connection — if all appliances are now electric, cancel the Synergy gas supply (ring Alinta/Kleenheat/AGL/etc. to cancel). Eliminates $200–$280/yr supply charge permanently.

3. Induction cooktop — return depends on current cooking frequency; moderate financial case; strong environmental case.

4. Space heating — electrify at appliance end-of-life, not prematurely.

Bundling the STC rebate

Each electric appliance that qualifies for Small-scale Technology Certificates (STCs) reduces your upfront cost:

• Heat pump hot water: approximately $300–$700 STC rebate
• Heat pump space heating systems: may qualify depending on product
• Solar system (if not already installed): the largest STC rebate

When bundling a heat pump hot water and solar installation through the same CEC-accredited installer, you may receive combined quotes and coordination benefits.

Electrification and solar savings synergy

Electrifying gas appliances doesn't just eliminate gas costs — it creates more electric load that solar can power:

Example: gas replaced by heat pump HWS on Midday Saver

• Heat pump runs 9am–12pm at 1.5kW average = 4.5kWh
• On Midday Saver super off-peak: 4.5kWh × 8.85c = 40c/day
• OR if solar installed: solar generation covers the 4.5kWh (free)
• Compared to gas: $1.20–$1.60/day energy + supply charge proportion

The combination of solar + electrification + Midday Saver creates a compounding effect: more things powered cheaply by solar or at 8.85c/kWh, fewer things on expensive fuels.

Is full electrification right for your household?

Strong case for full electrification:

• Gas supply charge is significant relative to your gas energy use
• Your gas appliances are approaching end of life
• You have solar or plan to install it
• You're on Midday Saver or planning to switch
• You're concerned about long-term gas price risk

Moderate case / take it step by step:

• You have a mix of old and new gas appliances
• Your gas use is high (heating-heavy household, cooking preference)
• You're not on solar yet

Weak case for electrification:

• Your gas appliances are new (0–5 years old)
• Your cooking preference strongly favours gas
• You heat heavily in winter and live in a well-heated house

Run the numbers for your household using the BillWise bill analysis tool — upload your most recent Synergy and gas bills to model the electrification payback for your specific consumption.