The Honda Smart Home, unveiled last month at UC Davis, is a technical showplace.
As a zero net energy house, which produces at least as much energy as it consumes, the home represents the type of construction the state of California is pushing as a tool to control carbon emissions.
No expense was spared in the building of the two-bedroom house, which has a large solar panel system on the roof to harvest energy from the sun. Those solar panels in turn send electricity to a car-charging system in the garage, where the Honda Motor Co. has one of its Honda Fit electric cars waiting to plug in.
The 2,000-square-foot house produces more power than it uses. A cutting-edge energy management system, designed and owned by Honda, serves as its energy brain.
Three departments at UC Davis collaborated with Honda and Pacific Gas & Electric Co. to build the house at the university’s West Village development. Researchers at UC Davis will monitor the many novel and common technologies in the house in order to assess how they can be used the future, said UC Davis spokesman Adam Gottlieb.
Some of these innovations include a geothermal heat pump system comprising eight 20-foot deep boreholes that will heat or cool the home’s floor and ceilings. That system made it possible to build the home without an air conditioning system. The geothermal pump system is expected to yield valuable information on the application of such systems to future home use, said Jonathan Woolley, associate engineer with the UC Davis Western Cooling Efficiency Center.
The home will also be used as a living space, with a member of the UC Davis community staying in the house for a year and driving the electric vehicle.
Zero net energy building is not a new idea at UC Davis, which touted its $300 million West Village development as the first big zero net energy project in the U.S. before it opened in 2011. That development now houses 1,980 students, faculty and staff spread out over three buildings. To date, it has not quite achieved the zero net energy goal; it generates 87 percent of the energy it consumes.
Many of the technologies found in the Honda House remain impractical for ordinary homebuyers. Neither Honda nor UC Davis disclosed the house’s price tag, but the array of technologies and the staff time used to make it a reality would put such a home way out of reach for all but wealthy buyers. The 9.5-kilowatt solar electric unit alone would cost a homeowner more than $20,000 to purchase.
“We cannot put a number on the cost of the house because this is, literally, the first time we’re deploying some of this technology,” said Ryan Harty, manager of Honda’s Environmental Business Development Office. “We’re talking thousands of engineering hours, and you can’t put a number on that.”
The Honda Home uses technological features to offset energy used by cars, lights and standard appliances. The excess energy the home was designed to capture is meant to offset potential future increases in energy needs, such as the addition of more occupants and increased daily commute times in electric vehicles.
Some of those involved in the building of zero net energy homes question whether such an approach will make for affordable homes. One of those is Taeko Takagi, vice president of product design at Zeta Design+Build. The San Francisco-based company builds the components of its modular zero net energy homes and buildings at McClellan Park in Sacramento.
“You can stuff a lot of money into anything and make it work,” said Takagi. “You can have a 20,000 square-foot single family home in Napa and it could – technically – be zero net energy because you can buy a lot of photovoltaics to replace whatever energy the house will use.”
Takagi said a more affordable approach is to assess what kind of energy use can be removed before starting the conversation about what technologies will be used to replenish it. “Then you don’t have the problem of trying to make energy that you could have just taken away in the first place.”
Takagi said Zeta has built small modular homes for architects and is building larger scale multifamily buildings using “low tech” practices and approaches to keep costs down. An example of its approach to single-family home building is a 1,561 square-foot, two-bedroom home erected in Oakland. That home, designed as zero net energy, included a 5.4-kilowatt photovoltaic system on the roof. The home cost $165 per square foot to build and was assembled from four factory-built modules.
Homeowners are clearly showing interest in the zero net energy concept. In the Sacramento area, both the Sacramento Municipal Utility District and PG&E report brisk demand from customers installing solar panels and looking to sell power back to the utility. PG&E has been adding about 2,500 such customers a month, said utility spokesman David Eisenhauer.
Call The Bee’s Edward Ortiz, (916) 321-1071. Follow him on Twitter @edwardortiz.