At first glance, Durango at Shadow Mountain looks like another cookie-cutter subdivision of new homes sprawling across a barren valley in the town of Menifee, Riverside County.
Step into a $577,990 model home on Hopscotch Drive, however, and the possible future of low-carbon, climate-resilient housing peeps behind the stucco and faux-stone facade.
In the garage, an elegant white battery fixed to a wall stores the electricity generated by the 16 solar panels on the roof. Next to the battery is an electric vehicle charger, and some owners will have the option of harnessing their car battery to provide extra power to their homes – an experiment aimed at turning electric vehicles into mobile power stations .
A high efficiency electric heat pump water heater is tucked away in a corner of the garage and a heat pump that heats and cools the house is next to the back patio. The 2,906-square-foot four-bedroom home’s open kitchen features an induction cooker that uses less electricity than a conventional electric model and emits none of the harmful pollutants of a gas stove.
In total, these devices will reduce energy consumption in Durango by up to 40% compared to a conventional home, according to builder KB Home.
But what you can’t see is what could really transform the energy system.
The 78 homes under construction in Durango are connected to form a microgrid, a self-contained electrical system that can operate independently of the California grid in the event of an outage. It’s an increasingly likely event as weather-driven wildfires, heat waves and storms trigger power outages.
An additional 141 homes being built in an adjacent subdivision, called Oak Shade in Shadow Mountain, will be connected to a second microgrid that can also harness solar power and batteries to maintain electricity during outages.
The two developments will share a 2.3 megawatt-hour “community battery” to provide additional power in the event of an outage. In energy jargon, Durango and Oak Shade are capable of being “isolated” from the power grid – archipelagos of light if the desert darkens.
“In California, when it’s really hot and there are fires, you’re at risk of turning off the power,” said Dan Bridleman, senior vice president for sustainability, technology and strategic sourcing at KB Home. . “We felt like there was probably an affordable way to build resilience, not just at the home level, but also in the community.”
So far, according to KB Home executives, around 50 homes have been sold and the first owners are expected to move in early next year. With prices ranging from $482,000 to $578,000, the homes are attracting young families out of coastal towns, the company said.
Solar energy company SunPower Corp., Southern California utility Edison, automaker Kia Corp., UC Irvine, Schneider Electric and the US Department of Energy are working with KB Home on the project.
The federal government provided $6.65 million to develop and test a first-of-its-kind microgrid technology and determine whether the Menifee microgrid could serve as a model for future residential developments. Over the next four years, a team from SunPower and researchers from UC Irvine will collect data and monitor the performance of microgrids.
“We want to see how we can improve owner resilience,” said Ram Narayanamurthy, emerging technologies program manager at the Department of Energy. “Electrification is really going to lead to a lower carbon footprint as the California grid becomes increasingly decarbonized.”
Microgrids, of course, won’t stop the spread of remote housing estates and strip malls, parking lots, and the long drives that come with them. But they do offer a way to decarbonize suburban sprawl.
They can also “increase the reliability of the electricity grid, play a role in mitigating the risk of forest fires [and] help make communities more resilient,” said Terrie Prosper, spokeswoman for the California Public Utilities Commission, the state’s energy regulator.
While other residents of Menifee are subject to rising electricity and natural gas prices, owners of Durango and Oak Shade will become power brokers. They will be able to sell excess electricity generated by their solar panels and stored in their home battery to Southern California Edison.
Collectively, microgrid homes can act as virtual power plants, providing electricity to help maintain grid stability during peak demand, such as during heat waves.
Each home’s battery is a 13-kilowatt-hour SunVault model from SunPower, which also supplies the rooftop solar panels. Heat pumps and smart thermostats are Wi-Fi enabled, allowing a home’s appliances, batteries and solar panels to be coordinated to maximize energy production and reduce costs.
This means, for example, that the 219 heat pump water heaters from Durango and Oak Shade can be transformed into “thermal batteries”. In the middle of the day, excess electricity generated by a home’s solar panels heats water for later use, when the sun isn’t shining and utility rates go up. This can reduce the need to fire natural gas power plants to meet nighttime demand.
SunPower’s technology manages a home’s energy system for homeowners, allowing homes to engage in energy arbitrage while their inhabitants are working or sleeping. If a Durango resident is commuting to a job in San Diego, for example – ideally in an electric car – the SunPower cloud can maximize the solar electricity that the resident sells to the utility or stores in their battery by turning down the thermostat and put the devices in economy mode.
When that same resident’s utility rates go up, the home can draw on the solar electricity stored in the battery. All homes are pre-wired for EV chargers, and about 20% of buyers have installed them during construction so far, said Matt Brost, vice president of SunPower.
“During the high solar generation times of the day, when homes often don’t use a lot of electricity, we believe the solar systems will more than sufficiently charge the homes batteries and the community battery,” Brost said. .
Microgrids could reduce utility revenue, but Southern California Edison supports Project Menifee for its potential to reduce customer costs and build grid resiliency, said Katie Sloan, vice president of programs and services. company customers. “This project will be a great plan for electrification in the future,” she said.
One day in November, construction workers at Oak Shade were assembling the wooden frames of a row of two-story houses overlooking rocky hills covered in chaparral. At the edge of development, Scott Hansen, vice president of forward planning for KB Home’s Inland Empire division, points to a plot of land where the community battery will be installed on a fenced pad. The battery, the size of a shipping container, will normally be charged from the grid, drawing solar power from surrounding homes only when needed.
Back at the Durango model home, Hansen gestures to the 5.6 kilowatt solar panel on the roof. That’s about half the power — and cost — of a solar system typically needed to power a similarly sized conventionally-built home. Indeed, homes in Durango and Oak Shade are built to the Department of Energy’s Zero Energy Ready Home standard, which requires a building to be so well insulated and sealed that a renewable energy system can offset most or all of its power consumption.
Hansen opened a large white panel attached to one side of the house, revealing the Schneider Electric Square D Energy Center. This smart panel controls every circuit in the home, balancing the electrical loads generated by different appliances and allowing the homeowner to choose which ones to power in the event of an outage.
Green labels indicate circuits that would be powered by the home battery in the event of an outage, including lights, power outlets (keeping Wi-Fi on), refrigerator, and microwave. High voltage appliances such as the stove and heat pumps are labeled in gray and would remain offline until the community battery kicks in and provides an additional 6 kilowatt hours of electricity per home.
“These houses are built so tightly that in the event of a power outage, they will stay cooler longer in the summer and the reverse in the winter,” Hansen said.
Once the community battery is online, Brost said, “it will efficiently power the whole house, but the homeowner won’t be able to run it all at once or charge a car, so he’ll have to choose what he wants to run.”
Some homeowners will have another option during a power outage: using their car to charge their home. Five homes in Durango and five in Oak Shade are being installed with two-way chargers made by Spanish company Wallbox that can transfer electricity from an electric vehicle battery to the home.
Although the Ford F-150 Lightning is the only electric vehicle sold in the United States with this capability, those owners can participate in a three-year trial to lease Kia EV6 crossovers imported from South Korea that have two-way batteries, a said Scott Samuelsen, a professor of mechanical, aerospace and environmental engineering at UC Irvine, who will design and manage the experiment.
Kia EV6 models sold in the United States have battery capacities ranging from 58 kilowatt hours to 77.4 kilowatt hours, up to six times the SunVault home battery storage. Samuelsen said it’s enough to power a home for hours or even days during a power outage, and the kind of thing he hopes “will be an integral part of an electric vehicle in the future.”
For KB Home’s Bridleman, the convergence of all these technologies in the home is quickly becoming a selling point, especially as climate change affects everyday life.
“People in California are acutely aware of this,” he said. “We’re seeing interest across the state in making our homes more resilient.”