I have a ten year old G scale set (Tweetsie Railroad) that I ran on about a 30' track years ago for my autistic son.  We moved several years ago and I am finally putting it together again but it will be 8' longer so I know I will have power issues.  It runs the hollow steel track and I am trying to figure out how to increase power in a cost effective way that is simple for an inexperienced railroader.  Thanks in advance for any advice.  This is G scale by the way.