Hundreds of cities and corporations are on the path to zero carbon emissions. For most, to achieve this ambition, the best path is to generate all energy with renewable electricity, then electrify all buildings and transportation.
At present, only one out of every four U.S. homes is all-electric. Most use natural gas for heating water, heating the air and cooking. Some also use gas for washing and drying clothes and dishes. Natural gas is typically 85 percent methane, a super pollutant that traps 100 times the heat of CO2 over its 16-year life in the atmosphere. Much new natural gas used in buildings comes from fracking, increasingly associated with polluting local watersheds.
Unless all homes and buildings are heated with renewable electricity, instead of natural gas, we will fail to fully decarbonize. The good news is there is an increase in all-electric building at the same time as there is a price decrease for renewables, heat pumps and energy efficient technology and materials. The following three complexes demonstrate that multiple dwelling homes can be designed for zero energy.
West Davis Village is an all-electric super-energy-efficient apartment complex that houses 2,200 students and staff living near the University of California, Davis. The community includes UC Davis research offices and Sacramento City College classrooms. I have visited the community on a number of occasions and toured the apartments. West Davis Village has been such a success that housing for 3,000 more apartments are being built in this public-private partnership of the University of California and Greystar Real Estate Partners, an international real estate developer and manager.
Megawatts of solar panels are on apartment roofs and parking structures. Residents stay cool on hundred-degree days with thick insulated walls, roof overhangs, window sunshades, and maximum energy efficiency. A biogas generator converts waste to energy. The complex uses smart energy management.
Smart water management is also included at West Village, incorporating drought-tolerant landscaping to minimize irrigation needs. Natural drainage systems include greenbelts that cleanse rainwater before entering the storm drain system. Water-saving toilets use only 1.28 gallons of water per flush; shower faucets deploy only 1.5 gallons a minute.
Many students bicycle to campus and into the town of Davis using bike lanes separated from cars. As there are no markets or restaurants in the complex, people also drive. West Davis Village was designed to be zero energy (ZE). It came close, but students surprised designers with unexpected plug loads, primarily from multiple gaming systems and minifridges of students not trusting roommates with their beer. All of us involved in sustainability have learned to expect the unexpected.
At GreenBiz’s conference in Oakland in October, VERGE 19, California Gov. Gavin Newsom reiterated the state’s commitment to be carbon neutral by 2045, with efficient electric buildings and mobility being key to using renewable energy which is already 36 percent of the state’s electricity. The state continues to update building code, such as Title 24, to make it more stringent in order to encourage homes and buildings to be solar, all-electric and super-efficient.
600 Soleil Lofts Apartments are being built and rented in Herriman, Utah, a growing city of 20,000 living 25 miles south of Salt Lake City. The homes are all-electric, including electric heating, hot water and cooking. Because the apartments are super-efficient, the installed 5.3 MW of solar should produce enough electricity in a year to match all energy use of this zero-energy community, which includes 100 EV chargers.
The 600 solar apartments, each with a sonnen lithium battery, create a virtual power plant with 5.3 MW / 12.6 MWh capacity. Sonnen has long been the intelligent energy storage leader in Germany, with 40,000 customers, many exchanging solar electricity with each other. Shell recently purchased sonnen.
Soleil apartments will be able to respond to price signals and deliver electricity to the local utility, Rocky Mountain Power. Grid-interactive energy-efficient buildings (GEBs) such as Soleil provide utilities with much needed load flexibility.
The vast area from Texas to Virginia leads in U.S. building electrification. 45 percent of new homes in these states are all-electric.
Near Austin, Texas, Whisper Valley will include 7,500 all-electric homes, 2 million square feet of commercial space, two schools and a 600-acre park. The first of seven villages is in development. Every house includes a geothermal heat pump, solar PV, smart home technology and a connection to the Google Fiber 1 GB network.
Each home is connected with EcoSmart’s ultra-efficient centrally installed GeoGrid, a community-wide geothermal loop system. The system provides geothermal heating and cooling. The community geothermal system goes 350-feet underground to take advantage of the constant ground temperature. This approach is especially cost-effective on hot summer days, when electric grids are often overloaded at peak hours with blasting air conditioning. The U.S. produces the most geothermal energy in the world.
Whisper Valley was voted as Green Builder Sustainable Community of the Year. These homes start at less than $250,000. Without the added cost of gas lines, all-electric homes can be less expensive to buy and operate.
Fully developed, Whisper Valley has the potential to be a zero-energy community. Mobility will be the community’s challenge. Will it attract enough markets, retail and services so that most trips can be done by low-carbon forms of mobility such as walking and bicycling? Travel to many jobs, as well as to downtown Austin, will require driving.
From fossil fuels to RE to ZE
All-electric homes and buildings speed our transition from using fossil fuels. Utah is one of 12 states where most electricity comes from coal. Texas electricity is primarily from methane and coal, but the state also leads the nation in wind power. 20 years ago, California’s percentage of renewables was less than Texas today. Now California is 36 percent electricity from renewables, even as the use of renewable energy (RE) is expanded to heat buildings and power vehicles.
Of the 113 million U.S. buildings, 70 million burn methane or other fossil fuels for heating and cooking. As RMI details, over time these buildings can be replaced or retrofitted to be efficient and all-electric.
These strategies were extensively covered when I attended the “Getting to Zero” conference that was sponsored by the New Building Institute (NBI) and the Rocky Mountain Institute (RMI), the ACORE Renewable Energy Grid Forum, and when I joined 3,000-plus sustainability executives at VERGE 19 (the three-day conference was 100 percent powered by a renewable microgrid).
Across the nation, millions are living in homes that are all-electric, efficient and smart. For those that can trust their housemates to share one refrigerator, some of these homes will be zero energy. These millions are leading a transformation to take full advantage of our abundance of sun and wind, and help cities and corporations to electrify everything to achieve fewer carbon emissions.