By far the easiest type of solar panel to use on your caravan is a portable panel. These come in a variety of shapes and sizes. But don't choose a panel that's too small as it will not charge your battery. On the other ha. One major advantage of the portable solar panel is that it can be set up to face the Sun directly. A solar panel tilted upwards in this way will produce much more electricity than one laying h. The portable solar panel is great. But if you do not want to set it up each day then a permanent installation might be better for you. However, be careful about what you fit to the roof of you. The efficiency of a modern semi-flexible solar panel is at least as high as a standard solar panel. When choosing a panel make sure it is built with 'monocrystalline' technology. This. The semi-flexible panel is glued to the roof of the van using a special adhesive. The cable from the panel is taken through a watertight gland to the interior of the van and is then conn.