How do flat plates compare with vacuum tube solar panels ?
On hot sunny days the flat plate panels will produce approximately the same amount of heat as vacuum tube panels of the same area. Under ALL other conditions, the vacuum tube panel will produce more heat than flat plate panels – usually by a very substantial amount. Flat plate panels perform very badly during cold conditions, windy weather, in overcast conditions etc. Some of the very best and expensive flat plate collectors can compensate for this with more advanced design, but they still do not perform as well as vacuum tube panels.
