Why Is My Electricity Bill So High With Solar Panels?

You paid for solar so the power bill would shrink. Then the quarterly bill turns up and it's barely moved, or it's gone up. It's one of the most common calls we take, and the person on the other end usually assumes they've been sold a dud.

Sometimes they have. Far more often the system is doing exactly what it was designed to do, and the bill is high for reasons that have little to do with the panels.

Short answer: most Sunshine Coast homes with solar still have high bills because they use most of their power after the sun goes down, export their daytime surplus for a few cents, and buy it back at night for many times more. A typical home only uses 30–50% of its own solar; the rest is exported for roughly 3–12c per kWh while grid power at peak costs around 25–35c. The other common causes are a system that has quietly stopped working, a feed-in tariff that's been cut, or a change in your tariff or household usage.

Below is how to work out which one is yours, and what actually fixes each.

Why is my electricity bill so high when I have solar panels?

In rough order of how often we find them on the Sunshine Coast:

It's often more than one at once, which is how a bill ends up looking like the solar "stopped working" when nothing is broken.

Reason 1: you use most of your power when the panels aren't producing

This is the big one, and it's simple arithmetic.

Your panels produce in the middle of the day. Most households use the bulk of their power from about 4pm onwards: cooking, air conditioning, hot water, lights, TV, laptops, the pool pump if it's on a timer. By the time demand peaks, the panels are winding down.

So you export during the day and import in the evening, and the price gap between the two is the problem:

Every kilowatt-hour you export earns single-digit cents. Every one you buy back after dark costs three to five times that. A typical Sunshine Coast home self-consumes only 30–50% of what its panels make, which means half or more of your solar is being sold cheap and bought back dear.

That's why two households with identical systems can have wildly different bills: the one running appliances at lunchtime gets far more from the same panels than the one that's empty all day.

What helps without spending anything:

• Run the dishwasher, washing machine, dryer and pool pump in the middle of the day, not overnight.
• If you have an electric storage hot water system on an overnight timer, ask whether it can be switched to heat during solar hours.
• Pre-cool or pre-heat the house in the early afternoon on hot or cold days, so the air conditioner is coasting rather than working hard at 6pm.
• Charge an EV during the day where you can.

Reason 2: your feed-in tariff has been cut

If your bill crept up over a couple of years without any change in your habits, look at the export credit line on your bill.

Feed-in tariffs in south-east Queensland are set by your retailer and they change. Many households signed up when the rate was much higher than it is now, and the retailer has since moved them onto a lower rate at a plan rollover. Same panels, same output, smaller credit.

A few households are still on the old Queensland Solar Bonus Scheme. That scheme has been closed to new connections for years, but existing customers keep their arrangement under its own terms. If you're on it, don't change anything on your system — not the inverter, not the size, not the retailer — without confirming first whether it would affect your eligibility. That's a conversation to have before any work is done, not after.

For everyone else, the practical step is to compare plans when yours rolls over. A plan with a slightly better feed-in rate but worse usage rates can easily leave you worse off, so look at both numbers together. We go into the detail in our guide to solar feed-in tariffs on the Sunshine Coast.

Reason 3: your system has quietly stopped working

A solar system that fails doesn't make a noise. The lights stay on because the grid picks up the slack, and the first sign is often the next quarterly bill, by which time it may have been offline for months.

Things we regularly find:

• The inverter is off or faulted. An error code on the screen, a red light, or nothing at all.
• A DC isolator has failed. Rooftop isolators are a known failure point on older Australian installs. Enclosures crack under UV, water gets in, and the switch fails.
• A breaker has tripped in the switchboard and nobody noticed.
• The inverter is running but derated, producing far less than it should, often because of high network voltage or an insulation fault.
• The monitoring dropped off after a new router or Wi-Fi password change, so nobody's been watching.

Inverters usually fail long before panels do. Plenty of systems installed in the 2011–2013 rebate wave are on their second inverter by now, or due for one.

If you suspect this is your problem, our guide to what to do when your solar inverter is not working walks through what you can safely check yourself and what needs an electrician.

Reason 4: dirty panels, shading or ageing

Less dramatic, but it adds up.

• Shading: the tree that was a sapling when the panels went on is now taller than the gutter. Even partial shade on one panel can drag down output from a whole string on older string-inverter systems.
• Bird droppings and lichen bake on and create hot spots that can permanently damage cells. Rain doesn't shift them.
• Salt film at coastal addresses dulls output even when the glass looks clean.
• Age: panels slowly lose output over their life. That's normal, and what the performance warranty is for.

Most Sunshine Coast roofs with a decent pitch get by with occasional cleaning, and rain does a lot of the work. Homes within about a kilometre of the water, low-pitch roofs and anything under trees need more attention. Our solar panel cleaning guide has the details.

Reason 5: your tariff or your usage has changed

The solar didn't change. Your house did.

• New appliances: a pool, a second fridge in the garage, a ducted air conditioner, a spa, an EV.
• People home more: working from home shifts usage, sometimes in solar's favour, sometimes not, depending on when you use power.
• Plan changes: a move onto a time-of-use tariff, or a rate rise at rollover. On a time-of-use plan, evening usage is the expensive bit, which makes the self-consumption problem above even sharper.
• Fixed charges: your daily supply charge is there whether you have solar or not. Solar can reduce what you pay for usage, but it can't remove the supply charge.

Pull up a bill from before the solar went in and one from now, and compare total kWh used, not just dollars. If your usage has gone up substantially, the solar may be doing its job and simply being outpaced.

How to check if your solar is actually working

You don't need to get on the roof (and you shouldn't). From the ground:

1. Look at the inverter on a sunny day around midday. Most show current output in watts or kilowatts and a daily total. If it's blank, showing an error, or reading zero in full sun, something's wrong.
2. Check the switchboard. Look for a tripped breaker labelled solar or inverter.
3. Open your monitoring app if you have one, and look at the production graph for the last few months. A sudden flat line, or a gradual slide, tells you a lot.
4. Read your bill. The export (feed-in) figure should be substantial on a working system. If exports have fallen off a cliff, generation probably has too.
5. Compare against what the system should make. For planning, we work on roughly 26 kWh a day averaged across the year for a 6.6 kW system and around 40 kWh a day for a 10 kW system on the Sunshine Coast. Your real figure depends on orientation, pitch, shading and season, and winter days will be well under those averages. But if you're seeing a fraction of that on clear days, it's worth a look.

If something looks off, don't open anything up. Photograph the inverter screen and call a licensed solar electrician.

Why are people getting rid of their solar panels?

You'll see this question pop up online, usually alongside stories of people pulling panels off. In our experience on the Sunshine Coast, households aren't abandoning solar. What they're doing is one of these:

• Replacing an old, failed system. Early systems, particularly cheaper ones from the 2011–2013 boom, are reaching the point where the inverter has died, the isolators are failing, and the original installer no longer exists. Sometimes repairing piece by piece costs more than a new system.
• Upgrading. Small early systems get replaced or expanded to suit a bigger household, an EV or a battery.
• Giving up on a system that was never right. Badly designed, shaded or oriented systems do exist.
• Reacting to a smaller feed-in credit. When the feed-in tariff dropped, it felt like the system had stopped paying off. It hadn't; the value moved from exporting to self-consumption.

If you're weighing up whether to remove or replace an underperforming system, get it tested first. Panels that still test well with a failed inverter are usually worth keeping.

When does a battery fix a high bill with solar?

A battery attacks reason one directly. Instead of exporting your surplus for a few cents and buying it back at night for many times more, you store it and use it after dark. A well-sized battery typically lifts self-consumption from that 30–50% range to around 80–90%.

On the Sunshine Coast, that's where the typical saving of around $1,000 to $1,500 a year comes from for a battery added to an existing system. Most batteries we quote model out at roughly 7–12 years' payback, faster for homes with heavy evening loads like air conditioning, pool pumps or EV charging.

A battery makes sense when:

• Your solar regularly exports a decent surplus during the day
• You use a lot of power between about 4pm and 7am
• Your existing system is healthy (or you're replacing a tired inverter anyway)

A battery won't fix your bill when:

• The real problem is a faulty system. Fix that first; a battery can't store power that isn't being made.
• Your array is small and there's little surplus to store. A big battery on a small system sits half-empty, particularly through winter.
• You're on an old high feed-in arrangement that makes exporting worthwhile.

The federal Cheaper Home Batteries Program takes a meaningful amount off an approved battery. Since 1 May 2026 it's worth roughly $252 per usable kWh, about $2,520 on a 10 kWh battery, and it steps down every six months. Full details are on our Queensland solar rebate guide. For how it works on a system you already have, read adding a battery to existing solar, and for what we install and what it costs, see our solar battery installation on the Sunshine Coast page.

The honest bottom line

Confirm the system is producing what it should. If it is, the bill is almost always about timing: when you use power versus when the panels make it. Fix faults first, shift what you can into the middle of the day, check your plan, and only then look at storage. Send us a recent bill and a photo of your inverter and we'll tell you plainly whether the problem is the system, the plan or the household.

Frequently asked questions

Why is my electricity bill so high when I have solar panels?

Usually because you use most of your electricity in the evening and overnight, when the panels aren't producing. You export your daytime surplus for roughly 3–12c per kWh and buy power back at night for around 25–35c at peak. A system that's faulty or offline, a cut feed-in tariff, shading, or a jump in household usage are the other common causes.

Why are people getting rid of their solar panels?

Mostly they're replacing old systems that have failed, upgrading small early systems, or removing ones that were badly designed in the first place. Some people also feel short-changed when their feed-in tariff drops, even though the panels are still cutting what they buy from the grid. Get a system tested before removing it; a failed inverter is far cheaper to replace than a whole array.

How do I know if my solar panels are working?

Check the inverter screen around midday on a sunny day for current output and any error codes, look for a tripped solar breaker in the switchboard, and compare your monitoring app and bill export figures with previous months. If the system is reading zero in full sun, or exports have dropped sharply, have it inspected by a licensed solar electrician.

Will a battery lower my electricity bill?

If your solar exports a decent daytime surplus and you use a lot of power in the evening, yes. A well-sized battery typically lifts the share of your own solar you use from 30–50% to around 80–90%, and battery retrofits we quote on the Sunshine Coast typically save $1,000 to $1,500 a year. It won't help if the system is faulty or too small to fill the battery.