Sometimes, the system briefly exports to the grid due to sudden changes in energy consumption.
As with all grid-solar-battery systems, the solar panels generate power during the day. This power is used firstly to support your household load, with any excess energy going to the battery. If there is still solar after this, it will feed back into the grid. At times of high-power usage, or at night and on low-sunlight days, the home draws power from the battery and as a last resort the grid.
From time to time, when solar is being produced but there is a sudden decrease in household load, the system can briefly export excess solar before charging the battery. This will only last for a very short period of time. Similarly, if there is a sudden increase in load, power might be imported until the system has turned on the inverter and adjusted to the increased demand. We refer to the sudden changes as “spikes”.
Another example of a spike is when the system briefly exports power to the grid to handle a sudden drop in household load. This might look like it’s exporting from the battery to the grid. In this case, the battery is assisting the household load and a sudden drop in demand occurs (e.g. when turning off appliances that consume large amounts of energy). Therefore, the battery displaces the excess power, usually to the grid. The battery cannot just switch off so a gradual adjustment takes place. This is normal system behaviour and is necessary for the long-term performance of the system.