Can timing and technology change what you pay?
Follow one home through a day. Add solar panels and a battery, switch electricity plans, and drag the clock to see where every kilowatt goes.
Step 1 · Predict
Step 2 · Build the home
Step 3 · Drag the clock
12:00 pm: no solar right now, so the home is running on electricity from the grid.
- Used so far
- 4.5 kWh
- Bought from grid
- 4.5 kWh
- Sold to grid
- 0 kWh
- Cost so far
- $1.46
The whole day
Electricity bought minus solar sold: $5.03
Usage costs only, excluding the daily supply charge. Energy left in the battery is valued at the feed-in rate.
Step 4 · Does timing matter?
What if you run the dishwasher at midday instead of 7 pm?
A 1.5-hour cycle. The answer depends on your plan, your solar and your battery: change them above and watch it update.
Run at midday
34c
extra cost to the day
Run at 7 pm
34c
extra cost to the day
About the same either way. With a flat rate and no solar, electricity costs the same whenever you use it, so the time of day doesn't change the cost.
Assumptions and limitations
- One illustrative home on a sunny spring day. A 6.6 kW solar system makes about 28 kWh; the battery is 10 kWh with 5 kW maximum power, and starts the morning 20% full.
- Household use is a typical shape (morning bump, small midday use, big evening peak), not your home. The dishwasher adds 0.7 kW for 1.5 hours.
- Prices are illustrative: flat 32c; time-of-use 48c (4–9 pm), 30c (7 am–4 pm), 20c overnight; solar exports earn 5c per kWh.
- The battery charges only from surplus solar and never from the grid, and it uses simple 95% charging efficiency.
- Costs exclude the daily supply charge and GST. Weather, season, plan and equipment change every number here. This is education, not personal advice or a savings forecast.
Related guides: get more from solar, battery storage, time-of-use tariffs.
Understand the science
Want to learn more? The articles go deeper on how it all works.