The Serpentine Collector Array solves the uniform flow rate problem of the parallel collector array.

Because it consists of one long continuous tube, there is no pressure differential to consider and even when two units are connected together few, if any problems are introduced through mixing or turbulence issues.

Heating is uniform over the entire device so hot spots are eliminated.

Problems:

• Hot fluid molecules like to travel upward but they must travel horizontally causing the water to travel in a spiral motion through the straight sections due to convection within the tube. This effect is known as drag, which causes stagnation and reduces efficiency. In fact it could be argued that every horizontal tube is of itself a bottleneck.
• If the tube is too small the flow rate is restricted by the aperture size.

• Connecting multiple serpentine collectors in parallel, as shown above, helps to minimise the restricted flow rate problem but it may not be a cost effective solution.
• Angling each horizontal tube section by at least 5 degrees upward reduces the drag but increases the overall panel length, which may be undesirable.