Sorry for taking so long to respond. I am disappointed because there was no explanation for what the Solar Park is for (I have a hard time locating what most/any hydrocraft items are for), I assumed that it was intended to replace the generator (which would have been awesome). Instead, it's used to re-charge batteries (as I understand it). This was a VERY difficult build for me and took several real time days to put together, only to find out that it wasn't what I thought it was. By then, the power was off and I wasted time preparing for solar power. So I restarted with a new game.
I do love most of the features in Hydrocraft, but I'm disappointed that there's not much of description about what some items (like solar park) are intended to do...especially since it takes so much work to finally complete one.