Why Your Electricity Bill Matters More with a Solar Battery
As Australians invest in rooftop solar and solar batteries, understanding your electricity bill isn’t just about tracking costs, it’s about unlocking savings. Whether you’re a homeowner or small business, learning how to interpret billing data and optimise battery use is the key to making the most of your solar investment.
Understanding Your Energy Bill – Line by Line
Australian energy retailers typically break bills into a few main sections. Here’s what to look for:
Key Components:
- Usage Charges (kWh): How much electricity you’ve consumed, usually in cents per kilowatt-hour (c/kWh).
- Supply Charge: A daily fixed fee, even if you don’t use power.
- Feed-in Tariff (FiT): The credit you earn from exporting excess solar power back to the grid.
- Controlled Load: A lower rate applied to off-peak appliances like electric hot water systems.
- Peak vs Off-Peak Usage: Some plans have time-of-use pricing; this affects how your battery is used and charged.
Internal link suggestion: See our solar battery range for time-of-use plans
How Solar Battery Impacts Your Bill
Installing a solar battery fundamentally changes your bill structure:
- Reduces Peak Usage: A solar battery discharges in the evening when energy prices are highest.
- Maximises Self-Consumption: Instead of exporting excess solar to the grid at a low FiT, you store it for your own use.
- Minimises Grid Dependency: With proper sizing, your solar battery can supply most of your evening energy needs.
Tip: Use your bill to measure how much energy you import from the grid after installing a battery. If it’s still high, you may need to reconfigure your system or change usage habits.
How to Calculate Your Real Solar Savings
Here’s how to work it out:
A. Without a Battery:
Savings = Solar Export x FiT + Reduced Grid Consumption
Example:
- Exported 300 kWh x FiT $0.08 = $24
- Used 400 kWh less from the grid x $0.30 = $120 → Total monthly savings: $144
B. With a Solar Battery:
Savings = Reduced Grid Consumption + Peak Price Avoidance
- You may export less but avoid using grid energy during peak times (up to $0.45/kWh)
- If your battery supplies 400 kWh/month, that’s potentially $180 saved, even without feed-in tariffs.
Using Your Bill to Adjust Battery Use
Look for These Patterns
- High night-time usage = Your battery might be undersized.
- Large export volume = Consider a larger battery to store more.
- Minimal FiT earnings = You’re consuming most solar on-site, a good sign!
Adjusting inverter settings or time-of-use scheduling can make a difference. Many hybrid inverters allow app-based control to charge batteries during solar peak or cheap off-peak rates.
Tariff Structures That Affect Battery ROI
A. Flat Rate Tariff
- One price for all times.
- A solar battery reduces overall grid use but doesn’t maximise ROI.
B. Time-of-Use (ToU) Tariff
- Peak: 3pm-9pm (most expensive)
- Shoulder: 7am-3pm, 9pm-10pm
- Off-peak: 10pm-7am (cheapest)
Best paired with a solar battery that discharges in peak hours and recharges during solar production or off-peak.
Tracking Performance Monthly
Set up a spreadsheet or use smart energy apps to log:
| Month | Grid Usage (kWh) | Export (kWh) | Battery Use (kWh) | Bill Amount |
| Jan | 210 | 320 | 250 | $102 |
| Feb | 190 | 310 | 270 | $97 |
Over 12 months, this gives you data to make an informed decision on:
- Battery upsizing
- Switching tariff plans
- Adding solar panels
Are You Eligible for More Savings?
Check if your area supports:
- Peak Demand Reduction Scheme (NSW)
- Cheaper Batteries for Homes (SA, VIC)
- Small-scale Renewable Energy Scheme (SRES)
These may offer rebates, or performance-based incentives.
Internal link suggestion: Learn more about rebates on Solar Rains Blog.
Common Mistakes to Avoid
- Only looking at the total bill: Always assess usage data and feed-in tariffs.
- Ignoring seasonality: Solar production is lower in winter; savings vary month to month.
- Wrong battery size: Oversizing reduces ROI; undersizing reduces savings.
- Not syncing battery with usage habits: For example, charging EVs during peak times reduces benefit.
Tips to Maximise Savings Beyond the Battery
- Use timers on heavy appliances (dishwasher, EV charger) during solar production hours.
- Adjust thermostat and hot water during the day.
- Monitor weather forecasts and manage battery discharge accordingly.
Example: On sunny days, let the battery charge fully and use less off-peak grid charging.
Choosing the Right Battery for Your Usage
Your electricity bill is the best guide to battery sizing.
General Guide:
| Monthly Usage (kWh) | Suggested Battery Size |
| 300-500 | 5-7 kWh |
| 500-800 | 10-12 kWh |
| >800 | 13-20 kWh |
Conclusion: Know Your Bill, Know Your Power
Understanding your bill isn’t just for budgeting, it’s a roadmap to solar battery optimisation. From knowing how much you export to how you use electricity by the hour, every line of your bill holds insight into your system’s real performance.
With the right knowledge, tools, and support from trusted solar suppliers like Solar Rains, you can maximize your savings, reduce reliance on the grid, and make informed decisions for the future.
FAQs
Yes, especially if you use more energy in the evening (peak hours). Savings are higher on time-of-use tariffs.
Typically between 7-10 years depending on usage, battery size, and energy prices.
You may not charge it fully each day, reducing efficiency and extending payback time.
Check your electricity bill or contact your energy retailer.
Not reliably. For full off-grid systems, you’ll need more panels, storage, and a backup generator.
