[bostik]

I wish I could find the article - there was a report on the effect of installed solar panels and the cost of AC on the (single-family) properties they were on. Would have been in 2016 or 2017, maybe.

But in any case... The overall reduction in energy use was about 5% better than calculated. The article stated that this was discovered to be due to the improved airflow between the roof and panels. Because the panels are installed 40mm-50mm above the roof, they leave effectively a narrow wind tunnel between themselves and the roof surface. This means that with the panels heating up, they cause an increased airflow over the roof.

This increased flow, in addition to the panels heating up instead of the roof, was enough to further reduce the energy required to cool the house down.

You must have been experiencing the same effect.