well this is a good question. We plan on using a totally electric system. However instead of conventional batteries we plan on using super capacitors... here is a wikipedia link for anyone who wants to know what a super capacitor is.
http://en.wikipedia.org/wiki/Supercapacitor
Here is another link to a similar power train
http://www.killacycle.com/about/
These are the types of technologies that we will be utilizing... except modified and tweaked for increased efficiency.