Why Is My Electricity Bill So High When I Have Solar Panels?

Last updated: August 2025
Have you recently received an electricity bill that is still significantly high despite having solar panels installed? If so, you are not alone. This is a frustrating situation for many Australian homeowners, especially those living along the Sunshine Coast. With the amount of sunlight the region receives, residents expect their energy costs to plummet.
The truth is that having a solar system installed does not come without its challenges. To reap the benefits of your solar energy investment and attain the amount of savings you were hoping for, it is crucial to understand the reasons behind the high energy costs.
Knowing How Your Solar Energy System Works
System Size vs. Energy Consumption Mismatch
Under-charging installation is one of the major reasons your electricity consumption is still high. Most homeowners fail to account for their actual energy consumption during the planning phase of their renewable energy setup. For example, a 5kW system may look good on paper, but households that come with multiple air conditioners, pool pumps, and EV charging stations will need significantly larger installations.
Renewable energy pros solar panel installation Sunshine Coast firms like Ahlec Solar make it a practice to perform energy audits before making a recommendation for system sizes. These assessments look into your usage history, future energy requirements, and roof space to make sure it is well optimised.
Timing Of Energy Usage Patterns
As with any Solar power Sunshine Coast system, energy is produced from 6 AM to 6 PM, with the system fully functional between the set hours. Households tend to consume the highest portion of energy from around the 5 PM mark as families come home for the day, prepare dinner, and wind down with the TV for the evening. Unfortunately, this coincides with the, ‘Use it or lose it,’ mentality for energy consumers.
Consider the following:
Air conditioning and Heating equipment
Electric cooking appliances
Water heating
Entertainment systems and Lighting
Clothes washers and dryers
Factors influencing the performance of solar energy systems
Shading and Orientation Problems
An issue that is very common, Shading Problems, can cause a very noticeable effect on the system's efficiency for the output. The way solar panels are normally linked means that any morning shadows from neighbouring buildings, trees, or other structures can greatly reduce output for the remainder of the day.
Sunshine Coast solar installations must consider:
Nearby vegetation growth over time
Construction development
Roof pitch and azimuth
Seasonal sun path fluctuations
Decommissioning and Servicing
Solar panels naturally degrade over time, and their efficiency wanes due to Australian dust, bird droppings, and severe weather. Without proper maintenance and cleaning, panels lose 0.5-0.8% efficiency every year.
Warning signs your system needs maintenance:
Accumulated dirt and debris
Overshadowing or damaged panels
Panel and inverter error messages
Performance monitoring system flags
Performance drops
Grid Connection and Billing Complications
Feed-in vs. Tariff Rates for Electricity
Queensland feed-in tariffs are between 3-10 cents per kilowatt hour. In contrast, purchasing power from the grid costs 25-35 cents. Each exported unit earned is far less than the imported energy.
Time-of-Use Pricing
Electricity retailers have adopted time-of-use pricing, where electricity costs vary at different times of the day. The highest rates fall between 4 PM to 9 PM, which is when most solar systems Sunshine Coast are set to deliver their minimal energy output.
Knowing how your bills are calculated can assist with improving your energy use. If your everyday jobs consume a lot of energy, try scheduling them for the daytime when your solar panels are producing electricity.
Seasonal and Weather Differences
Reduced Solar Production in Winter
The lower angles of the sun and shorter days that come with the winter months in Australia result in significantly lower solar generation. Locals from the Sunshine Coast are likely to see a decline of around 40 to 50 per cent in production during the June-July winter months, when compared to the peak summer months. This means that winter electricity bills are likely to be higher than normal, and that systems are operating as expected.
Weather Influence
Daily energy production can be negatively impacted by storms, prolonged cloudy periods, and other atmospheric happenings. Weather patterns such as La Niña and El Niño can affect the conditions for months and, in return, impact how the system performs and the electricity fees.
Energy Storage Options
Failure to Provide Energy Storage Options
In the absence of energy storage, excess solar production gets exported to the grid during the daytime at lower feed-in rates. Grid electricity is expensive during evening hours, and having to purchase it can be a burden. Battery systems help to ease this burden as they allow surplus generation to be captured during the day and stored for evening use, improving self-consumption and decreasing reliance on grid electricity.
Today’s lithium battery systems come with:
A warranty of 10-15 years
Automated Energy regulation
Provide backup power during outages
Improved return on investment
Battery System Sizing
An undersized battery will capture insufficient surplus energy, while oversized systems will result in unnecessary expenses. Expert solar consultants on the Sunshine Coast will ensure optimal battery sizing and solar output by closely assessing the energy and solar generation usage patterns.
Appliance Efficiency and Energy Usage Habits
Energy-Intensive Appliances
Older appliances also negate the benefits gained through solar energy. Devices like electric hot water systems, older air conditioners, and inefficient pool pumps are outdated and consume a lot of energy.
Consider upgrading to:
Heat pump hot water systems
Inverter air conditioning units
Variable speed pool pumps
LED lights throughout your house
Kitchen appliances that are energy-efficient
Managing Energy Use in the Household
Changing some simple habits can increase your return on investment when it comes to solar:
Run dishwashers and washing machines during the sunniest hours
Use timers for pool pumps to charge during peak hours
Preheat or precool your house during solar production hours
Charge electric vehicles during the day
Monitoring the System and Detecting Faults
Why Monitoring Performance is Important
Many homeowners never check their systems to see how they are performing, missing out on very critical faults or faults and degradation. Today, most systems can be monitored to provide real-time generation data, assisting a homeowner in identifying issues without delay.
Key monitoring metrics include:
Daily energy production
System efficiency ratings
Performance of each panel
Alerts and status of the inverter
Performance comparisons over time
Common System Faults
Sunshine Coast solar systems can have several technical faults:
Malfunctions and failures of the inverters
Problems with the DC isolators
Issues with the wiring or connections
Weather-related panel damage
Issues with grid connections
By having regular professional inspections, these issues can be identified and corrected before they adversely affect performance.
Expert Assistance from Ahlec Solar
Thorough System Evaluation
Ahlec Solar’s assessed specialists focus on evaluating and diagnosing implemented systems to streamline workflows and pinpoint optimisation areas. They evaluate technical and operational benchmarks as well as check for any necessary updates on the systems in place.
Tailored Adjustment Solutions
Depending on specific needs, Ahlec Solar suggests the following actions to assist customers:
Expand systems for added efficiency
Incorporate battery storage
Implement advanced energy management software
Upgrade appliances
Optimise energy usage strategies
Financial Aspects and The Return on Investment
The Payback Period
Achievable targets require focus on the following areas:
Savings from projected energy use
System upkeep expenses
Energy cost escalation for electricity
System replacement timeframes
Changes in subsidies and incentives from the government
Investment Return
Adequate direction from leading firms, like Ahlec Solar, guarantees the desired results from the renewable energy initiatives, as they understand local policies and regulatory frameworks, together with system design.
Consideration: Taking Steps for Better Outcomes
Soaring electricity expenses, even with solar panel installations, can be a result of undersizing the systems, low technical performance, poor user engagement, and the billing framework. Understanding these factors enables one to better strategise to fully leverage the renewable energy system they have put in place.
If your solar installation is incurring continuous elevated electricity expenses, it may be worth arranging for a professional evaluation. Ahlec Solar, for instance, has the right experience to pinpoint exact problems and offer solutions that are not expensive.
Like any other technology, solar energy systems need continuous fine-tuning and a few modifications to perform at their peak. Optimising your photovoltaic investment with professional guidance can ensure that it brings about significant savings in electricity costs for years.
High electricity costs may seem burdensome, but they should not put you off from your solar journey. Focus on your goals and use the knowledge shared here to optimise your system and gain the energy independence you desperately want.
FAQs
1. Why is my electricity bill still high even after installing solar panels? Several factors could be responsible, including an undersized solar system, poor energy usage habits, shading issues, or high evening electricity consumption when solar production is low.
2. Does the size of my solar system affect my savings? Yes. If your system is too small for your household's energy usage, especially with high-consumption appliances, it won’t offset enough of your electricity needs, leading to high bills.
3. What time of day should I use my appliances to reduce my electricity bill? Use high-energy appliances like dishwashers, washing machines, and pool pumps during daylight hours (typically 10 AM–3 PM) when your panels are generating power.
4. How does shading impact solar panel efficiency? Shading from trees, buildings, or debris can significantly reduce your panels' output—even one shaded panel can lower the performance of the entire system.
5. How often should solar panels be serviced or cleaned? Solar panels should be cleaned and inspected at least once a year to remove dust, bird droppings, or debris that can reduce efficiency.
Subscribe to my newsletter
Read articles from Andrew Hall directly inside your inbox. Subscribe to the newsletter, and don't miss out.
Written by

Andrew Hall
Andrew Hall
AHLEC Solar is a trusted solar energy company based on the Sunshine Coast, delivering high-quality solar panel installations, solar battery solutions, and off-grid systems for homes and businesses across Queensland. With a commitment to clean energy and sustainable living, AHLEC Solar offers expert advice, affordable pricing, and reliable service—from consultation to installation and maintenance. Whether you're reducing energy bills or going fully off-grid, AHLEC Solar provides tailored solar solutions backed by years of industry experience.