Judging by my initial comment on this map (but that was a very long time ago), I think the issue you may be facing is not so much the limit on the amount of energy as such, but the limited rate at which firepower can be delivered against the creeper using a conventional pipe...
Either way, Dad's maps are always worth a replay, so I'll take a look whether my theory is correct and revert..
UPDATE:
yup, you've gotta find a creative way of storing up enough energy and firepower to break out ..(this is one neat trick that'll help you on a lot of expert only maps)
Also, Dad is a sadist, so
don't just be careful about which upgrades you choose, but also about when you activate them..
This is a great map, thanks for giving me an occasion to replay it!
Good luck!!