Whole-home electrification: real costs and savings for WA households

Thinking about going all-electric but worried about the upfront cost? It's the question we hear most. Here are the numbers for a modelled, typical Perth household — what each step costs, and what it saves — so you can see where the money goes before you spend any.

The baseline: a typical gas + electric home

First, here's what a typical Perth household spends on energy today:

Current annual energy costs

| Item | Annual Cost | |------|-------------| | Electricity (6,000 kWh @ 32c/kWh) | $1,920 | | Gas supply charge | ~$120-200 (varies by retailer) | | Gas usage (heating, hot water, cooking) | $450 | | Petrol (15,000km @ $2.00/L, 10L/100km) | $3,000 | | Total | $5,420-5,500/year |

This is our starting point. Now let's see how electrification changes these numbers.

Phase-by-phase electrification costs

Phase 1: solar panels (foundation)

A 6.6kW solar system is the sweet spot for most Perth homes.

Costs: | Item | Before Rebate | After STC Rebate | |------|---------------|------------------| | 6.6kW system with 5kW inverter | $7,000-9,000 | $5,200-7,200 | | Installation | Included | Included |

Savings:

• Year 1 electricity reduction: $1,400-1,800
• Simple payback: calculator output from the installed price and annual savings inputs

After Solar, annual energy costs: | Item | Cost | |------|------| | Electricity (reduced by solar) | $400-600 | | Gas supply charge | ~$120-200 (varies by retailer) | | Gas usage | $450 | | Petrol | $3,000 | | Total | $3,970-4,250/year |

Savings so far: $1,250-1,530/year

Phase 2: heat pump hot water

When your gas hot water system fails (or proactively if it's old), replace it with a heat pump.

Costs: | Item | Cost | |------|------| | Heat pump hot water system | $3,000-4,500 | | Installation | $500-800 | | STC rebate | -$800-1,200 | | Net Cost | $2,300-4,100 |

Savings:

• Replaces $200-300 of annual gas usage
• Uses about $80-120 of electricity (mostly from solar)
• Net annual saving: $100-220
• Payback: calculator output based on your installed price, STC value, tariff, solar share, and replacement timing

After Heat Pump Hot Water, annual energy costs: | Item | Cost | |------|------| | Electricity | $500-700 | | Gas supply charge | ~$120-200 (varies by retailer) | | Gas usage (heating + cooking only) | $200-250 | | Petrol | $3,000 | | Total | $3,820-4,150/year |

Cumulative savings: $1,350-1,680/year

Phase 3: induction cooktop

Replace your gas cooktop with induction.

Costs: | Item | Cost | |------|------| | Induction cooktop (mid-range) | $800-1,500 | | Electrical circuit (if needed) | $300-600 | | New cookware (partial) | $0-300 | | Total | $1,100-2,400 |

Savings:

• Eliminates $100-150 of annual gas usage
• Uses about $40-60 of electricity
• Net annual saving: $40-110

The big win: disconnecting gas

Once you've removed gas hot water and cooking, you can disconnect gas entirely:

• No more gas supply charge: ~$120-200/year saved (varies by retailer)

After Induction + Gas Disconnection, annual energy costs: | Item | Cost | |------|------| | Electricity | $550-800 | | Gas | $0 | | Petrol | $3,000 | | Total | $3,550-3,800/year |

Cumulative savings: $1,860-2,110/year

Phase 4: reverse-cycle heating/cooling

If you're using gas heating, a reverse-cycle air conditioner (heat pump) is dramatically more efficient.

Costs: | Item | Cost | |------|------| | Split system (per room) | $1,500-3,000 | | Multi-split or ducted system | $8,000-15,000 | | Installation | Included |

For a typical upgrade (2-3 split systems): $4,000-8,000

Savings:

• Gas heating costs $150-300/year to run
• Heat pump costs $40-80/year for same heating
• Net annual saving: $100-220
• Plus superior cooling in summer

After Heat Pump HVAC, annual energy costs: | Item | Cost | |------|------| | Electricity | $600-900 | | Gas | $0 | | Petrol | $3,000 | | Total | $3,600-3,900/year |

Cumulative savings: $1,760-2,060/year (vs original $5,660)

Phase 5: battery storage

Add a battery to maximise solar self-consumption and provide backup power.

Costs: | Item | Cost | |------|------| | 10kWh battery system | $10,000-14,000 | | Installation | Included | | WA Battery Scheme (interest-free loan) | Reduces finance costs | | Net Cost | $10,000-14,000 |

Savings:

• Stores solar for evening use instead of buying from grid
• Net annual saving: $300-600
• Payback: calculator output based on battery size, usable capacity, evening load, tariff spread, export profile, install price, and backup value

After Battery, annual energy costs: | Item | Cost | |------|------| | Electricity | $200-500 | | Gas | $0 | | Petrol | $3,000 | | Total | $3,200-3,500/year |

Cumulative savings: $2,160-2,460/year

Phase 6: electric vehicle

The final step in whole-home electrification is replacing your petrol car.

Costs: | Item | Cost | |------|------| | Entry EV (new) | $45,000-55,000 | | Mid-range EV (new) | $55,000-75,000 | | Used EV | $25,000-45,000 | | Home charger installation | $500-1,500 |

Savings:

• Petrol costs eliminated: $3,000/year
• EV charging (mostly from solar): $300-600/year
• Net annual saving: $2,400-2,700
• Plus reduced servicing costs: $300-500/year

After EV, annual energy costs: | Item | Cost | |------|------| | Home electricity | $200-400 | | EV charging (home) | $200-400 | | Public charging | $100-200 | | Gas | $0 | | Petrol | $0 | | Total | $500-1,000/year |

Total annual savings: calculator output for the modelled household above (vs the original $5,660 baseline)

Summary: the full electrification investment

These are modelled figures for the illustrative household above. Treat them as a guide to the shape of the savings, not a quote. Actual payback depends on system size, battery size, tariff, export profile, install price, and household load shape. Use the calculator result with the shown inputs rather than relying on a fixed payback figure.

| Phase | Investment | Annual Savings | Payback | |-------|------------|----------------|---------| | Solar 6.6kW | $5,200-7,200 | Calculator output | Input-dependent | | Heat pump hot water | $2,300-4,100 | Calculator output | Input-dependent* | | Induction cooktop | $1,100-2,400 | Calculator output | Input-dependent* | | Gas disconnection | $0-200 | ~$120-200 | Immediate | | Heat pump HVAC | $4,000-8,000 | Calculator output | Input-dependent* | | Battery 10kWh | $10,000-14,000 | Calculator output | Input-dependent | | EV + charger | $45,000-75,000 | Calculator output | Input-dependent** |

*These items are replacements for appliances that would need replacing anyway **Compared to buying an equivalent new petrol car

Total Investment (excluding EV): $22,600-35,900 Total Annual Savings (excluding EV): $2,060-3,150

The smart approach: phased electrification

You don't need to do everything at once. Here's a practical timeline:

Year 1: solar ($5,200-7,200)

Start here. It's the foundation that makes everything else cheaper.

Year 2-3: replace failing appliances

When your gas hot water or cooktop needs replacing, go electric. Don't pay to repair gas appliances.

Year 4-5: disconnect gas

Once hot water and cooking are electric, eliminate the gas connection and its ~$120-200/year supply charge.

Year 5+: battery and EV

Add these when prices drop further or when your current car needs replacing.

Financing options

WA Battery Scheme loans

• Interest-free loan up to $10,000 for a home battery (Synergy customers)
• Spread the cost over 10 years
• Plus a $130/kWh rebate, capped at $1,300

Solar finance

Many installers offer:

• 0% interest for 12-24 months
• Low-rate finance over 5-7 years
• Compare the finance repayment schedule against the calculator output for your tariff, system size, and household load shape before assuming savings cover repayments

Green loans

Some banks offer discounted rates for energy efficiency upgrades.

A worked example: a phased switch

Take an illustrative 4-person Perth household — gas hot water (15 years old), gas cooktop, no solar, spending about $5,500 a year on energy. Here's how a two-year switch might play out:

Year 1:

• 6.6 kW solar installed: $5,200
• Failing gas hot water replaced with a heat pump: $3,100

Year 2:

• Gas cooktop swapped for induction: $1,200
• Gas disconnected: $150

Total invested: $9,650 Energy bill after: about $1,200/year Modelled saving: about $4,300/year Payback: calculator output for these inputs

From there, a battery and an EV are the natural next steps — added when prices drop or the current car needs replacing.

These are modelled figures for an illustrative household, not a record of a specific customer. Your own numbers depend on your usage, tariff, and the systems you choose.

Is it worth it?

For most WA households, electrification makes financial sense:

Solar alone: Often the first electrification step to model because the inputs are clearer than for batteries or EVs.

Heat pump hot water: Worth it when replacing an old system anyway.

Induction cooking: Worth it for health benefits + gas disconnection savings.

Battery: Worth it for energy security; financial payback is long but improving.

EV: Worth it if you drive 10,000+ km/year and need a new car anyway.

The key insight: you don't pay extra for electrification - you're investing money you would have spent on energy anyway, but now you own the asset.

Get your personalised electrification plan with our Electrification Calculator. See exactly what each upgrade would save for your specific situation.