Plants as food, plants as fuel?

I spent some time this week looking for YouTube clips that I can use to set the scene for the plant project, and stimulate discussion among my students. I found some really interesting stuff about the use of crude oil and plants that I wasn't aware of myself; I think I'm going to enjoy this project!
I have had some ideas about retrieving energy from plants that involve the breakdown of the unused cellulose in the stalks of crop plants when the crop is harvested. In Malaysia every year, farmers in Malaysia and the surrounding countries like to set fire to their fields, this creates a haze that has closed our school; this issue is what has prompted my thinking. Sadly, my research into this project has led me to find Cellulosic Ethanol production; always a day late and a dollar short!

I am still questioning the construction of my Driving Question - one of BIE's 8 Essentials for PBL - as to whether it is too vague:

Using plants, how will you produce your own food or fuel for a future of climate change, no oil and drought?

After a bit of thought and looking at other examples of driving questions, perhaps this will work:

Using plants, what do you have to do to produce your own food or fuel for a future of climate change, drought and an absence of oil?

Try again after watching the Wing Project!:

Using plants, how can I produce my own food/fuel for a future of climate change, drought and an absence of oil?

Considering the scope with which I have given this project - a 2 year course - the driving question really needed to encompass a lot of standards from the course. I hope I have managed this.