There are 3 mods that meddle with solar panels:
- GregTech: Changes the vanilla recipe
- Compact Solars: Lets you condense panels down. The next tier is made my surrounding a transformer with 8 of the like-tier panels (e.g. the LV array is 8 panels around an LV thransformer, and so on). The performance of the array is equal to the performance of the components (LV array is 8eu/tick, etc.)
- Advanced Solars: Gives different recipes for advanced panels (using new materials, etc.). The performance of the panels is also different, they have internal energy storage and work at night.