I documented my early solar experiments and the build of my first solar trailer on the http://www.pedelecs.co.uk forum. Search there for ‘Solar trailer build’ and you will find it.

Briefly, the trailer itself uses the base, axle, wheels and towbar from an old Burley Solo child carrying trailer, with a framework of 25mm thin wall aluminium tube mounted on top for the panels, and a luggage platform underneath.

The picture I want to put here is on another device. I’ll update it when I can.

The blue water pipe protects the front corners and anything I get too close to from damage.

The solar panels are three Sunpower 110Wp modules, so the maximum theoretical output is 330W.

Underneath on a front bulkhead made of thin plywood are two Elejoy MU400SP boost MPPT charge controllers, which convert the panel output to the voltage the battery requires.

The charge controllers. The yellow cable connects to the bike.

There is also a data logger, to tell me how much energy I have used and generated, and some jiggery-pokery involving two big diodes to persuade the Shimano system to accept my solar input.