Taking the volt-ampere characteristic of a low power solar panel with Arduino?

Question

Arduino

To study, you need to conduct an experiment: compare the efficiency of solar panels and their assemblies in different spatial positions. To do this, it is necessary to take an volt-ampere characteristic from each panel or assembly, say, every 10 minutes. Solar panels are small up to 5V, 0.3W like these .
There was an idea to use several electronic variable resistances connected in parallel (they are low-power), such as AD5246 or similar, as a rheostat, but I have never come across them ..
Is it possible to use them for such purposes? Does the respected community have any other suggestions?
PS and even the whole installation should work for a long time autonomously, without connecting to a PC and networks ...