Why Is Your Electricity Bill Still High With Solar? A Perth Owner’s Guide
Your Solar Bill Troubleshooting Guide - Made Easy
Solar Bills
Solar is supposed to make your electricity bill affordable. So, when the Synergy bill lands and it is higher than you expected, something in the chain is not doing its job. It might be the system, it might be the way your household uses power, or it might be the bill itself. This is one of the most common questions we get asked at Hughes Electrical, and in almost every case the cause falls into one of five categories.
This guide walks through each cause in the order a licensed electrician would rule them out. Some of what you find will be a warranty job for your original installer. Some will cost you nothing to fix yourself. And some will mean your system is simply too small for the way your household lives now.
Start With One Question: Is the System Actually Generating?
Before anything else, open your inverter app and compare this month’s generation against the same month last year. That single comparison rules half the possible causes in or out. A healthy 6.6kW system in Perth should produce roughly 28kWh a day averaged across the year, more in summer and less in winter. If your numbers are close to last year’s, the system is functional, and the answer sits in how your household uses power or how you are billed. If generation is clearly down, or the app shows nothing at all, the system is the problem.
Plenty of Perth homes run for months on a system that has partially or completely stopped generating. The inverter does not sound an alarm, it just quietly stops, and the grid picks up the slack at full price. The bill is often the first symptom anyone notices.
Cause 1: Your System Is Underperforming
If generation is down on last year, these are the usual suspects.
An inverter fault or derating. Inverters are the hardest working component in the system and Perth heat pushes them harder still. An inverter running in limited output mode, or tripping intermittently on hot afternoons, drags down generation without fully switching off. Check the display or app for fault codes and warning lights.
A tripped isolator or failed DC connector. A DC isolator that has tripped, or a corroded rooftop connector, can drop an entire string of panels. On a two string system that is half your generation gone overnight, and the inverter app can look almost normal at a glance.
New shading. Trees grow. A branch that cleared the array at install can be shading two panels by year four, and on older string systems the shaded panels drag down the whole string.
Panel degradation or failure. Quality panels guarantee a better year-on-year performance compared to budget panels, which will degrade at a faster rate. The quality of the panels shows in the productivity of the system in 5-10 years.
Cause 2: You Are Using Power at the Wrong Times
This is the cause most Perth owners have never had explained to them. Synergy’s buyback scheme pays around 10 cents per kWh for exports between 3pm and 9pm, and only around 2 cents outside that window. Meanwhile, power you buy from the grid costs upwards of 30 cents per kWh.
Read those numbers together and the problem is obvious. If your household exports solar all day at 2 cents, then comes home at 6pm and buys power back at more than 30 cents to run the oven, the air conditioner and the washing machine, your solar is earning cents while your usage costs dollars. The system can be generating perfectly and the bill barely moves.
The fix costs nothing. Run the dishwasher, washing machine and pool pump on timers through the middle of the day. Pre cool the house with the air conditioner in the afternoon while the panels are producing, rather than working it hard at full price after sunset. Heat hot water during the day if your setup allows it. Households that make this shift routinely cut hundreds of dollars a year off their bills without touching the hardware.
Cause 3: Your Usage Has Grown
A solar system is sized for the household it was designed for. Households change. A new pool pump, a spa, ducted air conditioning running hard through summer, an electric vehicle charging in the garage, teenagers who were toddlers when the panels went in. Any of these can add more daily consumption than the system was ever sized to offset.
Compare the total kWh consumed on your current bill against the same billing period two or three years ago. If consumption has climbed while generation has stayed flat, the system is not failing. It has been outgrown. Depending on roof space and inverter capacity, the answer might be extra panels, a larger system or a battery that shifts your excess daytime generation into the evening. Our residential solar page covers the options, our qualified electricians will design your system to cater to your individual needs and growing energy requirements.
Cause 4: The System Was Too Small From Day One
Some systems were undersized on day one, usually because the quote was built around a price point instead of the household’s actual usage. A quick check: divide your average daily consumption in kWh by 9, which is roughly the hours of solar production a Perth system sees across a day. That gives you a rough guide to the system size in kW your household needs. A family using 25kWh a day is looking at around 3kW just to break even on paper, and comfortably more in practice because generation and usage never line up perfectly.
If your system is well under that number, no amount of servicing or habit changing will get the bill where you want it. The system is doing everything it was built to do. It was just never built to cover your usage.
Cause 5: The Problem Is on the Bill, Not the Roof
Sometimes the system and the household are both fine and the bill itself is the issue. Check that the bill is based on an actual meter reading rather than an estimate, because estimated reads can overshoot badly and correct themselves later. Check the daily supply charge and your tariff, since supply charges apply no matter how much solar you generate and they rise over time. And if you have recently had meter or switchboard work done, confirm the meter is registering your exports at all. A metering fault can silently erase your feed in credits.
Line up three things: generation from your inverter app, exports and imports from your Synergy bill, and your total consumption. If generation is healthy but the bill shows little or no export credit, the fault sits in the metering or billing chain and is worth a call to your retailer.
The Five Minute Check Before You Call Anyone
Open the inverter app and compare generation against the same month last year. Look at the inverter for fault codes or warning lights. Check the bill is an actual read, not an estimate. Compare total consumption against the same period last year. And think about whether anything with high consumption has been plugged into the house since the system went in.
Those five checks take five minutes and will tell you which of the causes above you are dealing with.
Ready for an Upgrade? Get a Solar Quote from Hughes Electrical Group
If you have worked through the five causes and landed on a system that is simply too small for your household, no amount of troubleshooting will fix the bill. That is where we come in.
Get in touch to receive a quote followed by a site visit. We assess your roof, orientation and actual energy usage before recommending anything, so the system you end up with is sized around your household rather than around a price point. Our licensed electricians handle the design, the installation and the grid connection paperwork in house, with no subcontractors and no sales pitch.
Phone 0437 206 869, email info@hugheselectrical.au, or request a quote online. We are based in O'Connor and we service across the Perth metro area. For more on how we approach solar, see our residential solar page.
