Many Australian homeowners invest in solar energy systems with the expectation that their system will consistently reach its maximum rated output—say, 10kW. However, it can be disheartening to discover that your new system rarely, if ever, hits that peak, even on the sunniest of days.
A significant yet often overlooked reason for this is export limits, which govern how much excess energy your system can send back to the grid. These export limits can seriously curtail your system’s peak production capabilities, resulting in a noticeable difference between the expected and actual energy output of your solar installation.
Export limits are caps set by your electricity provider on how much unused solar energy you can send back (feed-in) to the grid. For single-phase electricity consumers in Australia, the typical export limit is 5kWh. These limits are in place for several reasons:
In the following section, we’ll delve into how these export limits influence your solar system’s production, forcing adjustments based on your household’s energy needs and the export cap set by your electricity provider.
Export limits play a key role in shaping your solar system’s performance, limiting not just the electricity you can export back to the grid but also capping your system’s total output. The inverter, which is the brain of your solar system, uses these export limits to manage and adapt the amount of electricity being produced. This ensures that the total power generated—your home’s consumption plus the electricity sent back to the grid—doesn’t exceed the limit set by your electricity provider.
For a clearer understanding, let’s examine two scenarios with a solar system size of 10kW:
Scenario 2 (with increased home usage):
In both scenarios, the combination of your home’s energy usage and the export limit determines the maximum output your 10kW solar system can achieve. This also reveals the amount of energy produced but lost due to these restrictions. Even with perfect sunny conditions, if your home’s energy consumption and the export limit are already maxing out, your system will not be able to produce at its full 10kW capacity.
Export limits can be a roadblock to fully utilising your solar energy system. But there are effective strategies to navigate around these restrictions. These solutions focus on smart energy consumption and technology investment, enabling you to maximise your system’s efficiency and financial benefits.
Smart Energy Consumption During Peak Solar Hours
The idea here is simple but effective: use more electricity when your solar panels are generating the most energy. This could involve scheduling energy-intensive activities like running your dishwasher, laundry machine, or electric car charging to coincide with peak solar hours. This approach not only reduces your reliance on the grid but also allows your solar system to produce energy closer to its peak capacity.
For instance, if you know that your solar system generates the most electricity between 10 a.m. and 3 p.m., that’s the best time to run these high-consuming appliances. By doing so, you increase your home’s energy usage, which means less electricity needs to be exported back to the grid. As a result, you can use more of your solar panel’s maximum generating capability.
Investing in Battery Storage
Another way to get around the export limit is by installing a battery storage system. Brands like Tesla and Sungrow offer high-quality batteries that can store excess energy generated by your solar panels. Instead of sending that excess energy back to the grid (and hitting your export limit), you can store it for use during non-peak solar hours or nighttime.
For example, if your 10kW solar system generates 8kW during peak hours, and your home uses 4kW, a battery can store the remaining 4kW. This way, when the sun sets, you can switch over to using the stored energy instead of drawing from the grid. It’s an effective way to maximise the utility of each kilowatt your system generates, allowing you to operate closer to the system’s peak capabilities.
Understanding export limits is crucial for maximising the efficiency of your solar energy system. Whether you’re a homeowner or a business owner, being aware of these limitations and how they interact with your energy consumption patterns will help you make more informed decisions about your solar installation. By using more of your generated energy or investing in battery storage, you can better align your system’s performance with its true potential.