Fitting two panels in an East - West configuration overcomes some of the drawbacks of not having a south facing location.

The payback period may double, as more panels are required and they fail to obtain maximum benefit from the midday Sun.

Within the limits of the installation, individual evacuated tubes can be rotated for maximum efficiency.

There is considerable attenuation as the sunlight passes through the atmosphere at a shallow angle (early morning and late evening) and reflectance as light strikes panels at a shallow angle (below 30o) is severe.