Haus 8 + 10 are equipped with photo-voltaic (PV) solar panels to generate 60-70% of the homes expected household electrical use. Naturally all systems do have a back up however the more energy that can be displaced with this clean green energy source the smaller the carbon footprint of this home and the lower the utility bill.
Did you know that in Alberta our electricity still comes predominantly from coal fired plants? That's right, one of the filthiest sources of electricity out there.
The electricity generated from these panels is tied back into the grid to feed the homes needs first and other electricity demands in the city second.
To answer your next question - yes, you are credited for the energy you generate but don't use.