The number of home microgrid communities is picking up, spurred by natural disasters, increasing energy prices and a desire to combat climate change.
For example, energy costs were the main driver for the Silvies Valley Ranch outside of Burns, Oregon, where off-grid microgrids for each of 600 homes under development makes more financial sense than paying the local utility $7 million to run utility lines to the ranch.
Meanwhile, the Housing Initiative Partnership (HIP), Emera Technologies and Pepco are moving forward on a residential microgrid project at a subdivision of net-zero, low-to-moderate income houses with the support of a $200,000 grant from the Maryland Energy Administration (MEA).
And interest in home microgrids is surging in California in response to wildfires and public safety power shutoffs. Microgrid companies say that demand is being driven by people who want to avoid outages. Among those people are luxury buyers who say they’re not solely interested in return on investment; they want resilience.
Now comes a plan from Horton World Solutions (HWS) — a builder that focuses on sustainability — to construct 200,000 homes with microgrids in the Dallas-Fort Worth, Texas, metropolitan area and the Sun Belt region. The energy storage systems — based on an innovative zinc-ion battery design said to be safer than the traditional lithium-ion batteries — will participate in energy markets where applicable. The income will be shared with homeowners, said Terry Horton, CEO and founder of HWS. He and his brother also founded the Texas-based homebuilding company, D.R. Horton, which describes itself as the largest homebuilder in the US by volume of homes built.
Road to net zero
Construction is expected to begin by the fourth quarter of 2022. The home microgrids will typically add about $20,000 to the cost of the houses and can be included in the total cost of a mortgage, said Horton.
“The ultimate goal at HWS is to provide net-zero homes. We’ve built HWS on the foundation of sustainability and putting our planet first,” said Horton.
HWS has formed a partnership with battery company Salient Energy under which Salient will provide its zinc-ion batteries as alternatives to lithium ion, a material that is experiencing supply chain delays and can present safety risks under certain circumstances.
“The desire to provide affordable, resilient net-zero housing to first-time homebuyers has been a guiding principle at HWS. One of the largest, clearest paths toward this pursuit is including residential energy storage,” said Horton.
Salient Energy designed its zinc-ion batteries to have the same power, performance and size as lithium-ion systems. The zinc-ion batteries can pair with residential panels and allow customers to disconnect from the grid during outages, said Ryan Brown, co-founder of Salient Energy. The battery technology is the result of research conducted at the University of Waterloo in Ontario led by Salient co-founder and chief technical officer Brian Adams, who, after completing his Ph.D. on lithium batteries, decided to investigate zinc-based batteries.
Join OhmGrid and Emera Technologies June 2 at Microgrid 2022 for a panel discussion, “Microgrids for Homes and Neighborhoods.” See full conference agenda.
Zinc ion is readily available and doesn’t have the safety issues associated with lithium ion, which can experience thermal runaway, said Brown. His company in January 2021 garnered a $1,583,125 grant from the California Energy Commission to support the design and assembly of its zinc-ion residential storage systems as an alternative to lithium ion. In 2020, the company “graduated” from Shell’s GameChanger program, which aims to help bring early-stage technologies to reality.
Most non-lithium-based batteries are designed for long duration storage and tend to be large. Salient designed its zinc-ion battery to provide the same power and be the same size as a lithium ion battery so it could easily serve as an alternative to lithium ion, said Brown.
Salient expects to scale up and build gigafactories by 2025, which Brown said should cut the cost of its batteries to half as much as lithium ion counterparts. In the meantime, the safety associated with zinc-ion batteries will help the batteries reach scale — because they can be installed anywhere in residential settings — and lower costs, said Brown. Lithium-ion batteries, on the other hand, generally require more installation considerations because of the potential for thermal runaway and fire.
“Our goal is to make a sustainable, affordable alternative to lithium ion,” said Brown.
The advantage of modular design
Salient’s batteries are modular, so homeowners can purchase additional batteries if needed. In most installations, the Salient batteries will provide four hours of storage, but that time period can be increased by adding additional batteries.
“We started as battery nerds and realized its potential quickly in a world where lithium is increasingly constrained,” he said.
The 200,000 homes from HWS will be constructed using the HWS energy-efficient building system. It replaces framing, house wrapping and insulation with one product. The structures are lightweight and easily shipped, according to company materials. They save money by avoiding the use of skilled framers and laborers for assembly. The company said the building system is made up of recycled plastics, requires no lumber and has twice the insulation value as traditional building systems.
Horton is happy to work with a group of battery nerds who can help address climate change.
“I’m 73 years old. It’s nice to do business with a young group of inventive people doing great work. This is important for our planet,” said Horton.
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