Net zero buildings don't just practice energy efficiency, aim for LEED certification, install solar panels, etc. these buildings actually use no net energy from the grid, or go even further in their "zero" duties. Typically a net zero building will leverage on-site renewable energy to generate enough power to cover all of the building's energy consumption. Some net zero buildings will also use off-site renewable energy or renewable energy certificates to supplement the building’s energy generation, but all of the building's energy use must come from renewable sources to be considered “net zero”.
While some net zero buildings may leverage the grid, others are entirely "self-reliant" and can operate independent of the grid. There are additional "zero" considerations that ZEBs can achieve as well:
- Site ZEB: A building that produces at least as much energy as it uses in a year, when accounted for at the site. This is what is described above and is required in net zero buildings.
- Source ZEB: A building that produces at least as much energy as it uses in a year, when accounted for at the source. "At the source" means including the energy used to transport the energy to the building, which accounts for transmission loss during delivery of the electricity from the plant to the building. Such losses can be significant, as much as 6.5%.
- Emissions (carbon) ZEB: A building that produces at least as much emissions-free renewable energy as it uses from emission-producing energy sources annually.
The following buildings are some of the most well-known net zero energy buildings, each with an array of unique and innovative features that take green building to the next level.