ideas for building a large (2m x 1m) heated bed that will require the least power?

[iDig3Dprinting]

At that size, you're looking at a rather large hibachi grill.

In fact, re-purposing a commercial flat grill might be your best bet... Good luck.

Thanks for that,

It made me think of catering hotplates, they even have a flat printable metal surface.