Nice open source project. Wish it worked battery powered.
http://www.hello-robo.com/#
everything works Battery-powered - it depends on the Batteries you are using. Ask @Florian_Horsch_flouS
Of course thats true 
I prefered they allocated a place for the battery in the design of the robot.
One of the mainstays of Friday, by Heinlein is the concept that everything becomes significantly easier when you develop better batteries…
That’s certainly true. Everything includes electric vehicles (Tesla) to airplanes (Boeing Dreamliner)
The main point he makes, is that energy is Plentiful… just maybe not where you want it. They use a plethora of different power generation techniques, and then just charge + ship the batteries around. Houses become ‘wireless’ because there is no need for powerlines.
Energy is plentiful ??? Everything has a cost, including Energy.
There’s plenty of energy sources, we just don’t get it from the right places, no? The earth is bombarded with sunlight + heat, yet we make very, very (relative) effort to make use of this potential source.
I believe in Nuclear power. However it requires expensive R&D. Additionally due to its potential for bad use, the R&D on this subject develops so slowly.
I haven’t read enough to be an expert on the energy generation requirements, nor possibilities.
I’m pretty happy with Nuclear power, provided the waste equation balances and the ‘OH NO, NOT NUCLEAR!’ issue can be sorted - probably best done by placing it ‘out of the way’, and then using the superbatteries to ship the power to where it is required instead.
sip lah