Page 7 - Zero Net Energy Case Study Homes-Volume 1

A key California policy landmark was Governor Schwarzenegger’s 2006 executive order es- tablishing “big, bold” energy goals for California, chief among which was that all new residen- tial construction should be ZNE by 2020. The energy code that will go into effect on January 1, 2020, has been adopted, and while not yet requiring ZNE, it represents a significant increase in energy efficiency for new homes, and also sets a U.S. precedent in requiring installation of photovoltaics.
Along with further progress toward ZNE, forthcoming State policy developments and technol-
ogy investments will inevitably focus on reductions in emissions, or ‘decarbonization’ – via
ii
electrification, among other measures. This is reflected in allusions herein to all-electric ZNE
homes as “zero carbon.” While it’s only possible today for a grid-tied home to be carbon-free in the rare instance where the home is all-electric, ZNE, and already served by emissions- free electricity from the grid, every all-electric ZNE home has the potential to operate carbon- free, when all electricity supplied by the grid comes from clean energy sources – a very real prospect. During his last months in office this year, Governor Brown signed SB 100 into law, committing California to transition to 100 percent emissions-free electricity by 2045. A number of California municipalities may achieve that transition well ahead of 2045.
The Case Study Projects
Members of the ZNE community outside California – in places that have “real” weather – sometimes scoff at the lack of challenge of accomplishing ZNE here. Admittedly, our populous coastal areas benefit from benign climates, but we also have both very cold climates, such
as Redding (similar in heating degree days to Chicago), and very hot ones, such as Palm Springs. Other factors also make this a challenging environment for housing innovation, among them high costs, a highly mobile workforce, and a notoriously litigious culture. Thus creating successful, marketable, ZNE projects is a non-trivial feat.
All the projects represented here have met the pinnacle of ZNE achievement: verified site ZNE. That is, not only was each project designed to be capable of achieving ZNE, but utility bills provide objective evidence of occupants’ energy use yielding ZNE in actual operation over the course of a full year. Further, site ZNE (explained in the introduction) is the most dif-
iii
ficult definition to meet.
site ZNE (to which source ZNE is equal, for all-electric projects) is an achievable benchmark. These proofs of viability are absolutely critical to supporting the State’s likely push towards residential electrification in years to come. The project developers whose work is showcased here are thus to be both congratulated and thanked for their significant contributions to the future of housing in California, and beyond. Read on, and benefit from their experience.
—Ann Edminster, Principal, Design AVEnues LLC
These projects therefore demonstrate, importantly, that operational
i The Net-Zero Energy Coalition conducts an annual inventory based on self-reporting by ZNE project teams, who record projects in design and construction as well as completed, and with energy performance (modeled or measured) within 10 percent of ZNE. ZNE-ready homes
– e.g., those participating in the US Department of Energy’s Zero Energy Ready Homes pro- gram – are also included. http://netzeroenergycoalition.com/zero-energy-inventory/
ii California Energy Commission business meeting, May 9, 2018.
iii The reasons for this are explained in Zero Energy Buildings: A Critical Look at the Definition,
Torcellini, et al., 2006.
Zero Net Energy Case Study Homes: Volume 1 v
FOREWORD ZERO NET ENERGY CASE STUDY HOMES