A Bold Plan for ZNE
In 2007, the California Public Utilities Commission (CPUC) adopted the new goals for residential and commercial construction. A collaboration of the CPUC’s regulated utilities, California Energy Commission (CEC) and over 500 individuals and organizations developed a bold plan. All residential buildings in California must be Zero Net Energy (ZNE) by 2020. All new commercial construction in California must be ZNE by 2030.
Definition and Purpose of ZNE
A ZNE home is one where the value of the energy produced by on-site renewable energy resources is equal to the value of grid energy consumed annually by the, measured using the California Energy commission’s Time Dependent Valuation (TDV) Metric.
TDV is the cost-effectiveness and energy valuation methodology used in development
and implementation of California’s Title 24 Building code. The TDV is a metric of energy
cost effectiveness. TDV evaluates whether a building-code requirement will save consumers
money on their utility bill over the life of a new home compared to no requirement.
Features of a ZNE Home
Fortunately, there are proven construction methods for every climate that allow builders to construct comfortable, efficient, and healthy homes. These best practices don’t require hard-to-find materials or a change in construction sequence. ZNE best practices require a “whole house” approach to building that recognizes how each part of the home works together to provide a comfortable, safe, and durable shelter. These best practices include the following.
- Superior insulation R-value and installation
- Airtight building construction
- Efficient HVAC systems
- Shading and reflective surfaces to minimize air conditioning
- Well-designed mechanical ventilation
- Photovoltaic solar electricity