Version 1.14.4 DOES NOT work with Java 11. MORE! Since 4.33r you can create custom panels with custom textures, names, and FE rates! Read the /.minecraft/config/solarflux/_custom/README.txt or watch the tutorial video!
The mod comes by default with 8 different tiers of solar panels (fully configurable) Solar Flux Reborn adds solar panels that generate FE or RF.