Solar, Batteries and Time-of-Use: Why Your Electricity Bill Still Has a Supply Charge

Solar has changed how much electricity a home buys from the grid, but it does not automatically remove every line on an electricity bill. With daily supply charges, time-of-use prices and lower export credits, the useful question is how well a system reduces the electricity you still need to buy.

For many households, the goal is to use more of their own solar during the day and, where it makes sense, store some for evening use. A good design is based on the home, its tariff and its seasonal energy use—not a promise that every bill will disappear.

Solar does not cancel the daily supply charge

A daily supply charge—sometimes called a service charge—is a fixed amount billed for each day the premises remains connected to the electricity network. It can cover connection, metering and other service costs. Rooftop panels and a battery can reduce grid imports, but they do not remove that fixed charge from the tariff.

Export credits may reduce the total amount due on a bill, but the supply charge still appears while the grid connection remains active. Going off-grid is a separate whole-home decision involving storage, backup and reliability planning; adding more panels alone does not make a grid-connected supply charge go away.

Retail plans differ. For example, an Energy Made Easy listing for one Brisbane plan has shown a daily supply charge close to $2 and a solar feed-in tariff of 1 cent per kilowatt-hour. That is one plan example, not an average or a recommendation. Rates, eligibility and conditions can change, so check the current offer for your postcode and usage.

Why using your solar can be worth more than exporting it

A feed-in tariff is the credit your retailer gives you for electricity exported to the grid. It varies by plan and may be a single rate or change with the time of day or amount exported. Some plans pay only a few cents per kilowatt-hour for daytime exports.

When you use a kilowatt-hour of solar at home, you avoid buying that kilowatt-hour from your retailer. The saving depends on the import rate that would otherwise apply. Government guidance explains that feed-in tariffs are generally lower than retail usage rates, so using suitable appliances while solar is available can be more valuable than exporting the same energy. A battery can store surplus solar for later, although its value depends on the system cost, tariff, usage pattern and how often it can charge.

That does not mean exports should always be driven to zero. The best result depends on your whole plan, including export rates, time-of-use periods, demand charges, export limits and any battery settings. Compare the total plan—not just the advertised feed-in tariff.

Time-of-use plans change when electricity is valuable

On a time-of-use plan, the rate you pay for imported electricity can vary between peak, shoulder and off-peak periods. Some plans also include demand charges. A smart meter may be needed, and the exact periods and prices depend on the plan. “Dynamic pricing” is not the same on every offer, so check the current fact sheet before changing retailers or tariffs.

South East Queensland households may also be eligible for the optional Solar Sharer Offer. It provides a free-power window from 11 am to 2 pm for eligible customers with a smart meter, subject to the offer’s terms. The daily supply charge and charges outside the free window still apply. For some homes, shifting energy use or charging a battery in this window may affect what system size or battery operation makes sense.

Size a solar and battery system for the site and the seasons

A system should be assessed against actual consumption, not only the latest bill total. If you are considering a battery, look at how much solar surplus is available to charge it, when the home needs that stored energy, and what happens during winter. Winter generation can be lower while heating, hot water and other household demand may be higher.

• Review a full year of electricity bills and smart-meter interval data where available.
• Identify daytime and evening use, including air conditioning, hot water, pool equipment and electric vehicles.
• Assess roof orientation, shading, usable area and realistic seasonal generation.
• Check inverter capacity, network export limits and whether excess generation could be curtailed.
• Compare battery capacity and charging assumptions with the home’s winter surplus and evening demand.
• Compare the full plan’s supply charge, import rates, feed-in tariff and any demand charges.

A larger rooftop array may help a home use more energy and provide more opportunity to charge a battery in less favourable weather. But there is no single system size that suits every property. Roof space, network limits, load shape, tariff and the upfront cost all matter. A battery may improve self-consumption and backup capability, but its bill savings do not automatically pay back its purchase price.

What to look for in a solar quote

Ask the installer to show the assumptions behind the proposal: expected generation by season, estimated self-consumption and exports, battery charging and discharge settings, tariff rates used in the estimate, export limits, and any backup loads included. A useful comparison explains what the system is expected to do and what it cannot remove—especially fixed charges that remain while the property is grid-connected.

Greenbank Solar is based in Greenbank and services South East Queensland. We can review your site, electricity use, existing equipment and plan details before recommending a solar or battery option. Request a tailored assessment, or read our guides to time-of-use tariffs, daily supply charges, using solar during the day and assessing a home battery.

Useful independent guidance

• Australian Government: electricity pricing plans, tariffs and feed-in tariffs
• Australian Government: how solar and batteries can reduce bills
• Australian Government: Solar Sharer Offer eligibility and terms
• Energy Made Easy: compare electricity plans for your postcode

Retail offers and tariffs change. Check your current retailer’s plan documents and use current consumption data before making a system or plan decision. Information reviewed 9 October 2026.

This article was written with AI assistance and may contain slight errors or omissions. Confirm current rates, plan terms and system-specific advice with the relevant provider or a qualified solar professional.