The photos show two 40 watt fluorescent tubes driven from a 12v battery supply. As fluorescent tubes emit a lot more light than the equivalent wattage of a globe, the advantage is a lot more illumination from the available solar panel.
Originally I built this project to provide lighting for a chook shed as it was too far from the SEC to justify the expense of running a 240v line.
Below are a few photographs of the finished project.
The two inverter circuits fitted into a twin 40W light fitting.