Solar and working from home in Perth: why WFH changes everything

Before widespread remote work, a typical Perth household had two low-consumption periods during the day: while the adults were at the office and the kids were at school. Solar generation peaked from 10am–2pm, but most of that electricity was exported to the grid at low feed-in rates while the house sat empty.

Working from home changes this fundamentally. Daytime consumption rises — computers, monitors, lighting, home office heating and cooling — and that consumption now coincides directly with solar generation.

The commuting household vs the WFH household

Commuting household (typical pre-2020 pattern):

• 7am–9am: high consumption (showers, breakfast, multiple people getting ready)
• 9am–3pm: low consumption (~$150–300W baseline, refrigerators, standby)
• 3pm–7pm: rising consumption (school pickups, cooking, AC)
• 7pm–10pm: peak consumption (appliances, entertainment, EV charging)

Solar generation peaks 9am–3pm. For this household, most of that solar is exported. Self-consumption ratio without battery: approximately 25–35%

WFH household (work and school-aged kids home during day):

• 7am–9am: high consumption (morning routine)
• 9am–5pm: sustained moderate-high consumption (computers × 2, monitors × 2, desk lighting, video calls, home AC or heating, lunch cooking, perhaps a child at home)
• 5pm–9pm: peak household consumption (evening routine)

The 9am–5pm period now has significant consumption that overlaps directly with solar generation. Self-consumption ratio without battery: approximately 55–70%

What this means in dollar terms

For a 6.6kW Perth solar system generating approximately 9,500 kWh/year:

Commuting household (30% self-consumption):

• Self-consumed: 2,850 kWh × 33.26c = $948/year avoided grid costs
• Exported: 6,650 kWh × 6c average DEBS = $399/year
• Total annual benefit: approximately $1,347

WFH household (65% self-consumption):

• Self-consumed: 6,175 kWh × 33.26c = $2,054/year avoided grid costs
• Exported: 3,325 kWh × 6c average DEBS = $200/year
• Total annual benefit: approximately $2,254

Difference: $907/year more in solar value — from the same panels, simply because the usage pattern shifted.

On a $7,000 system after rebates:

• Commuting household payback: approximately 5.2 years
• WFH household payback: approximately 3.1 years

WFH-specific load considerations

Home office baseline consumption:

• Desktop PC + monitor: 80–200W (gaming rigs can reach 300–500W)
• Laptop: 15–65W
• External monitor: 20–40W
• Desk lighting: 8–15W (LED)
• Laser printer when printing: 200–400W (idle: 10–15W)

Two people WFH, 9am–5pm: Approximately 200–500W continuous. Over an 8-hour workday: 1.6–4 kWh/day of additional daytime consumption compared to an empty house.

Air conditioning while WFH: A 2.5kW split system in a home office running 6 hours/day: approximately 9–12 kWh/day — a substantial load, but one that falls almost entirely within solar generation hours.

Video conferencing: Doesn't significantly increase power consumption per se, but keeping the setup powered on through the day (rather than sleeping between meetings) maintains that continuous baseline load.

Sizing solar for a WFH household

A commuting household might size solar to cover evening consumption + export. A WFH household should size to cover daytime consumption first, then export.

WFH-optimised sizing:

• Identify the home office's peak daytime load (computers + AC + cooking + appliances)
• Size the solar system to cover or exceed that daytime load
• The additional generation above daytime consumption can either be stored in a battery or exported

Practical sizing:

• Small WFH setup (1 person, laptop + small AC): a 6.6kW system easily covers daytime consumption
• Large WFH setup (2 people, multiple monitors + ducted AC): may warrant 10kW+ to reliably cover daytime peak
• Home with electric hot water heating (heat pump): running it during the day adds another 500–1,000W of beneficial daytime load

Does a WFH household need a battery?

With 55–70% self-consumption already achieved without a battery, the incremental value of a battery is lower for WFH households than for commuting households who currently export most of their solar.

A battery helps WFH households with:

• Covering the 5pm–9pm consumption (after the office is closed, before they go to bed)
• Blackout protection
• Midday Saver peak rate avoidance (3pm–9pm at 55.33c/kWh)

But the battery isn't needed to capture daytime solar value — the WFH usage pattern already does that. Solar-first investment is even more clearly the right order for WFH households.

Self-consumption ratios are illustrative based on typical Perth household patterns. Actual ratios depend on household appliance mix, working hours, and system size. Synergy A1 rate 33.26c/kWh effective 1 July 2026.