After Hurricane Beryl, Microgrid-Equipped Grocery Stores and Homes Weathered Outages for More Than a Week in Houston
When Hurricane Beryl slammed into Houston on July 8, knocking out power to 2.2 million customers, many grocery stores lacked the power to provide food to customers or keep their products cool.
Long lines formed at gas stations – consisting in part of residents who wanted to fuel their generators with gasoline to power their homes. Tree limbs toppled onto roads and a field hospital was created at a football stadium to meet the needs of people with medical challenges, said Allen Schurr, chief commercial officer of Enchanted Rock, which provides microgrids.
As of July 15, as many as 200,000 were still without power.
Texas Gov. Greg Abbott gave the utility company CenterPoint Energy until the end of the month to create a plan for minimizing future outages or be subject to executive orders – which he didn’t detail – to address the outages.
H-E-B stores were safe havens providing food
Amidst the chaos, H-E-B grocery stores continued to operate throughout the outages, relying on microgrids from Enchanted Rock that kept power going 24-7. In addition, residential customers with microgrids from Sunrun – which has thousands of customers in Texas – kept lights on, air conditioners whirring and avoided food spoilage. Some of these customers weathered the outages while neighbors went without power for eight or nine days, said Amy Heart, senior vice president of public policy at Sunrun.
Enchanted Rock, at the peak of the outage, operated 140 microgrids simultaneously. “That was a record for us,” said Schurr. The company supplied 210 MW to its customers during the crisis.
The customers included the area’s H-E-B grocery stores, some chemical plants and food processing facilities, health care facilities and water and flood control operations. The company also provided power to all of H-E-B’s food distribution centers, said Schurr.
Mission accomplished by Enchanted Rock
“We are doing our small part to help the citizens of Houston get through this,” Schurr said. “We’re not providing air conditioning, but we can make sure that food is available and health care facilities are supported. That’s our mission, to see critical infrastructure supported.” He added that the outages were a true test of the company’s model.
PowerSecure had 76 microgrids support 119 utility outage events with seven still in operation as of July 14, said Eric Dupont, senior vice president of PowerSecure.
“We have operated through July 14 at a total runtime equivalence of 151 days, 8 hours and one minute across our microgrid systems to support our customers,” he said. The microgrids, powered by natural gas and diesel, provided 97 MW in response to Hurricane Beryl.
Microgrid owners help neighbors and neighborhoods
Those protected by microgrids opened their stores and homes to residents who needed to charge electronic devices, take showers or cool food. H-E-B set up areas in their stores where people could sit and charge their phones, said Schurr
In some cases, residential microgrid owners ran electrical lines to their neighbors, said Heart.
Sunrun customer Jeff Wright didn’t know that his neighborhood had experienced an outage until he heard the noise from his neighbors’ nearby generators, he said. His Sunrun system–made up of solar PV and two Tesla Powerwalls–kicked in automatically.
Wright installed the system in July 2022 because he wanted peace of mind. He previously lived in Puerto Rico, where Hurricane Maria knocked out his power for about six weeks.
“Not having electricity for six weeks makes you understand what you have to do to get by. It was an awful experience not having electricity,” he said.
Microgrids can also support the grid in VPP programs
For many people and businesses, microgrids provided refuge during the outages. But the technology is powerful enough to do much more by supporting the grid, said Heart. As more and more Sunrun customers embrace storage, along with solar, these resources can be aggregated to form virtual power plants (VPP).
On July 18, Sunrun said it had supplied over 48 MW of power from its CalReady VPP over four consecutive nights the previous week. More than 16,000 Sunrun customers’ solar and battery storage systems supplied energy to the California grid, according to a company press release.
Sunrun has increasingly been able to pool customers’ solar and battery systems as interest in the technologies has picked up. In 2023, 15% of Sunrun solar customers nationally bought batteries, said Heart. This year, that percentage soared to 50%, with 70% to 80% of customers adding storage in certain areas, she said.
Ninety to 95% of the time, the batteries are not in use and could be part of a VPP.
Creating an environment supportive of VPPs
In Texas, Heart is a member of the state’s Aggregated Distributed Energy Resources Task Force. She hopes the task force will help create markets attractive to VPPs.
After Winter Storm Uri, the Electric Reliability Council of Texas created a VPP program quickly–within a year, said Heart. But the program is limited in scope. Solar and storage owners only have the option of signing up for a program with two retail electricity providers: Tesla and David Energy. She’d like to see that expanded.
Sharing solar and battery resources with the grid
“We need to get more solar and batteries out on the distribution grid to serve customers and have these VPP programs in place to encourage homeowners to share resources,” she said. “Enrolling only through a few companies is counter to providing as many choices as possible.”
Other barriers are slowing progress in Texas.
Technology requirements that apply to utility resources are sometimes being imposed on residential systems, said Heart.
Another challenge is financial. VPP programs need to pay residential participants at rates that are high enough to entice them to participate.
In addition, the programs should make it easy to sign up, said Heart.
Seeking resilience to protect families
As ratepayers experience more outages and calls for conservation, homeowners are beginning to seek out resilience options. In 2022, 40 states issued requests for electricity customers to conserve energy, Heart said.
The homeowners who are fielding these requests are looking for ways to protect their families.
“When they get these requests, people start asking, ‘What can I do for my family?’” Heart said.
