So I'm in the homestretch and I'm waiting for the last quest chain to play out before I can finish off the threat. However, I'm getting about 1 quest mission a month at best and I'm starting to feel the pinch with all of the UFO intercepts I'm running. Downed UFOs don't grant much E-115, if any at all and my small fleet of plasma and fusion Avengers are steadily eating into my reserves. Is there a good late game source of E-115, or should I be mothballed my fleet in favor of no E-115 vessels until the final push?