Intimmydation is correct.
you want to farm Anakin's ETA Starfighter.
However since you get 285 free fleet energy per day, you can actually farm the clone ship and Anakin's ETA at the same time.
5 attempts = 80 energy for all Stage1/Hard fleet battles.
5 attempts (no node refresh) for Clone ship = 80
10 attempts (25 crystals spent on a node refresh) for Anakin's ship = 160
80 + 160 = 240 energy per day spent on those nodes.
Now, that leaves you 45 energy per day left to try new nodes to advance further. You don't really need more spare energy than that since the clone ship and Anakin's are both worthwhile and, more importantly, failing repeatedly at nodes you can't win isn't going to get you anywhere. If you don't beat the next node on your first try, you might beat it on your next try, but probably not. Limiting yourself to spending only 45 energy on those failures is a good thing.
In fact, if you're sure you're going to fail, you can just farm a normal difficulty node 4 or 5 times for gear. What will get you past the next node is just slowly, surely upgrading your ships as new Ship Building Credits etc. become available. Upgrading your pilots will help as well, of course, but you're level limited on what gear you can add to them. So try every day to beat that next node, but don't pour so much energy into those attempts that it's just a waste.
Budgeting 240 energy for those 2 farms with only 25 crystals spent on node refreshing is probably the best thing you can do to make sure you're spending both energy and crystals efficiently.
Later on you'll have more nodes available to you to farm, but this is really the best i can recommend right now.
