Why does solar charging stop when the Do Not Charge Price limit is exceeded?

If you are using a price source (eg Amber or AEMO spot price) and set a Do Not Charge Price limit, you may notice that solar charging is stopped when the price limit is exceeded. This may be unexpected, as you might consider solar energy to be free and that the price limit should only apply to grid imports.

However, when you consume your own solar you are forgoing the feed-in credit that you would have earned if that excess solar was fed into the grid. Thus the "price" of your own solar is actually the feed-in price at the time. For example, if the wholesale price spiked to $5 / kWh, you would effectively be paying $5 / kWh to charge your EV.

When charging from solar, Charge HQ will stop charging when the feed-in price exceeds the Do Not Charge Price.

When charging from the grid, Charge HQ will stop charging when the import price exceeds the Do Not Charge Price.

If you are charging from a mix of solar and grid using Solar+Grid mode, Charge HQ will use the import price if less than 1 kW of solar is available for charging, otherwise it will use the feed-in price.

Still need help with Charge HQ?