Energy: Generally, the way to go is to get your solar power plant to somewhere between level 20 and level 27 (I go with 26), then switch over to solar sats.
I like this way of doing things because it means that I don't 'waste' resources on solar plants that I could be using on mines, but, if I do lose my sats, I can still keep my production up to a level where I can quickly build up sats again.
The thing with the satilites is that even if you lose them once (or twice), paying 600K crystal to build 200 satalites 3 times is still alot cheaper than paying for a level 30 solar plant.
And fusion sux. takes us fields, drains deut, etc. I used it when I was starting out the uni and was getting raided a lot, but now, sats are cheaper in the short run and the long run!