Solar strategy in the east

I think at least part of the difference can be attributed to reduced cell temps in the shoulder hours. First, the ambient temp is lower in the morning and late afternoon hours (at least it is where I am). Second, the sun is considerably off-axis during those hours, both resulting in lower panel cell temps. So the "heat penalty" paid by MPPT might be as much as 11-13% at midday in Salvo's example, but could realistically be only 5% in the early and late hours.