Net Zero Energy Consumption means that over the occupancy of the home, there is no loss of energy over the year. The home collects energy from the sun and is so well constructed that it loses a very small amount through the walls, windows floors or ceilings.
It is in the neophyte developmental stage in this country,with plenty of research in and around it, but an awful lot of independent ideas and disagreements as to which aspects should take precedent when it comes to really finding that zero point in energy costs.
Thank God for Oregon Energy Trust, and their independent and honest consultation as to how it all works. These people do not have an agenda to promote (no dog in the fight).
The largest amount of energy is used for heating and cooling the air. Next comes hot water production, and finally lighting for most families.
The good news for people in the Portland area is with PGE as electricity supplier, the meter will spin backwards, when you are producing more power from your solar panels than you are consuming resulting in a credit to your family.