Although solar forecasts are not very promising this time, it again permits to discharge to 30%, as the carbon intensity during the next day is expected to be especially low. Instead of drawing carbon-intensive grid energy at night, the demand is thereby shifted to the next morning where the batteries are charged to 60% using cleaner energy.
In this case local generation is low, but the grid is relatively clean (maybe it's v windy, not sunny), so it's ok to run down the local store of greener energy in the battery