One of the leading sources of greenhouse gas (GHG) emissions is the building sector, which according to UNEP contributes as much as one third of total GHG emissions, primarily through the use of fossil fuels while operational. The U.S. Department of Energy estimates the share of the U.S. Energy Consumption associated with residential buildings to be 21 percent and commercial buildings to be 18 percent. Radically altering the negative impacts of climate change can be achieved by creating buildings and communities that are zero energy. The long-term advantages of moving toward zero energy buildings (ZEBs), whether residential or commercial, are the same: lower environmental impacts, lower operating and maintenance costs, better resiliency to power outages and natural disasters, and improved energy security.
As zero energy buildings have piqued the public’s interest, the momentum has slowly spread to zero energy homes as well. Some of the drivers encouraging the trend are cities and states adopting zero energy policies, solar costs falling to record lows and demand growing for zero energy buildings globally. Typically, the most common renewable energy source for a zero-energy home is a roof mounted photovoltaic (PV) array. But zero energy homes must be efficient in addition to having the means for energy production. Energy efficiency (EE) is in fact at the core of zero-energy projects, and this concept can be a key innovation in the world of residential energy efficiency program design. Without a solid, high-functioning energy foundation, few projects would have enough space for a PV array large enough to meet their annual energy needs.
The next few years are key for the growing zero energy movement, if it can strategically insert itself as major player in the entire construction industry ecosystem. As the market for zero energy homes starts to open, a concerted effort is needed to push the net-zero agenda, both from the top down (policy) and the bottom up (grassroots entrepreneurs).
Before we dive deeper in the drivers, let’s get clear on the terms. At the most basic level, a zero net energy home is one that produces as much renewable energy as it consumes each year—the “net” referring to the annual balance between energy production and energy consumption.
In many circles, zero net energy is being replaced by the more generic term “zero energy.” But zero is not as simple as it seems. A closer looks reveals zero exists on a spectrum, with a range of levels that comprise the zero energy movement. The Net Zero Energy Coalition study “To Zero and Beyond, Zero Energy Residential Buildings Study” delineates subcategories of net zero energy. Zero energy ready means the home can supply 90 percent or more of its annual energy demand (or could, if/when renewable energy is added or system capacity is increased). A net producer supplies 110 percent or more of the annual energy demand. The Thousand Home Challenge is an independent initiative that refers to deep energy reduction projects in existing homes, whether or not they include renewable energy.
Policy and Programs Drive Market Adoption
California, home to 46 percent of residential zero energy buildings in the United States and Canada, significantly leads the market. Massachusetts, in second place, has 7 percent of the total.
The common ground between these states are specific initiatives, policies and programs targeting zero energy goals. California has the advantage with its large size and population, but several factors have contributed to its top dog status. According to the Net-Zero Energy Coalition study, “in 2007, the California Public Utilities Commission (CPUC) and California Energy Commission (CEC), adopted an Energy Efficiency plan with the aspirational goals in 2007 that all new residential construction in will be zero net energy by 2020, and all new commercial construction in California will be zero net energy by 2030. More than just a goal, these agencies have deployed training, design assistance, grants, competitions, research and development, and educational programs to make the goals a reality.”
Local policies, mandates and codes, with a variety of creative methodologies and protocols, drive a significant portion of zero energy construction activity in a handful of states and regions. For example, Connecticut puts on an annual CT Zero Energy Challenge design and build competition that awards cash prizes to its winners, while educating and demonstrating how to build super high-efficiency homes. And Boston holds its extremely successful E+ Green Building Program that highlights its agenda for innovative, energy-positive projects as prototypes for the future.
Adoption Push Strategy
In contrast to the top-down approach by policy and programs, activity in certain cities is driven from the ground up, by grassroots architects, builders and developers who focus on a daring push market adoption strategy. These early proponents of zero energy have developed large-scale multifamily projects that have had significant impacts on the concentration of zero energy buildings in the cities in which they build.
A good example of push marketing strategy is Northwest Land Park LLC of Sacramento. It’s in the process of developing 800 homes designed for zero energy performance. On an even larger scale, in Davis, California, the University of California joined with Carmel Partners to develop the largest existing multifamily zero energy community in North America, housing nearly 2,000 residents. Zero energy will soon become a reality in residential EE program design: UC recently reported that the project is 82 percent of the way toward meeting its energy needs onsite.
The exciting news is that whatever the specific driver, the general forecast is for current zero energy market activity to continue to escalate, creating more widespread market adoption and significantly reducing global carbon emissions. The Franklin Energy design team continues to monitor developments in this area and we look forward to designing residential and multifamily programs that incorporate distributed energy resources (DERs) to help achieve this goal.
Engineering Product Manager
Amin Esmaeili is a leader of innovation within engineering, combining impressive experience with years of education to produce proven results. He is responsible for the development of new program solutions and the design of new grid optimization and demand side management programs. Amin is also involved in quality assurance and collaborating with utility clients for the outcome evaluations of implemented programs. He holds bachelor’s and master’s degrees in industrial engineering and a PhD in industrial and system engineering from Wichita State University.