On May 11, 2021, the first day of the Microgrids 2021 Virtual Conference, hosted by Microgrid Knowledge, the 4-week long webinar began with a session titled, “Microgrids as Reliability Heroes.”
The session began with a welcome from Elisa Wood, Editor-in-Chief of Microgrid Knowledge, and an explanation about why microgrids have gained so much popularity lately. She theorized that the advancements in energy technology have made the field exciting, but that, more importantly, the technology “is on the side of angels.” To exemplify the latter point, she referenced the public safety power shutoffs in Northern California in late 2019 that threatened the lives of any resident who depended upon electric medical equipment, such as respirators or oxygen tanks. During the 28-hour long black-out, the Blue Lake Rancheria Tribal Utility came to the rescue by offering up its microgrid to any resident with critical medical needs.
After her introduction, Wood passed the microphone to Tim Echols, Vice Chair of the Georgia Public Service Commission and the session moderator, who then introduced the three panelists: John Griffiths, Founder of CONTECH-CA; Allan Schurr, Chief Commercial Officer of Enchanted Rock; and James DiLiberto, CEO and Principal Electrical Engineer of the AZZO group of companies.
Powering Through A Public Safety Shut-Off
Starting the session, Griffiths began with the San Benito Community Clinic project in Northern California, which was inspired by the devastation in Puerto Rico after Hurricane Maria in 2017. Fearing the impact that a public safety shut-off could have on the clinic’s most vulnerable patients, the president of the clinic envisioned a building capable of operation 24/7 in the event of a catastrophic grid failure in a historically underserved community.
After reducing the building’s load needs as far as they could, CONTECH-CA installed a microgrid consisting of an 80-kW solar array on the roof and a 550 kW/h battery. They also integrated the already-existing generator for an added layer of resilience.
Since completion of the project in 2018, the clinic has provided continuous, renewable power to the community with seamless switches between the grid and battery power and back.
Winter Storm Resiliency
In the next segment, Schurr focused on building resiliency in Texas in response to increased winter storms as a result of climate change. His experiences with the February 2021 Texas storm emphasized the value of long-duration generating systems that could potentially provide power for several consecutive days.
The deep-freeze caused by the storm set new records for load requirements for 8 consecutive days. The cold temperatures left several power stations unable to operate which resulted in rotating outages. At any given time, four million customers were without power.
At the time, Enchanted Rock was operating more than 200 microgrids in Texas. For the first 4 days of the deep-freeze, about half of those microgrids used natural gas to support the utility grid. Once the outages began, half of Enchanted Rock’s microgrids switched to island mode to support individual customers while the other half continued to support the larger grid.
According to Schurr, “That 8-day event was a substantial test of the value of resiliency [in] microgrids, both in support of the grid and in support of specific customers.” The storm also affected businesses that were not fully prepared for this type of grid outage, Samsung, for example, lost $270MM at their Austin, TX chip plant during this storm.
Protecting Private Businesses Down Under
For the third segment, DiLiberto described a case study from South Australia that assessed the region’s vulnerabilities and the steps taken to address them.
Beginning on September 28th, 2016, a “once-in-fifty-years” storm caused a blackout across all of South Australia. Although solar and wind energy were the initial scapegoats for the power failure, DiLiberto presented photos that showed that it was the infrastructure itself that couldn’t handle the stress and literally bent over in half from the force of the Antarctic Gulfstream winds. Homes and businesses were without power, and cities such as Adelaide suffered gridlock as traffic signals stopped functioning.
In the wake of the storm, private businesses and the South Australian Produce Market collectively reviewed the feasibility of onsite energy generation in the hope of improving resiliency and lowering energy costs. Ultimately, they decided upon an island-able microgrid supported by a 2.5-megawatt solar photovoltaic array and 4.2 MWh battery with a fuel-efficient diesel generator as back-up. The array recharges the batteries before then sending any excess energy into the wider grid.
The effects of climate change have already begun to rear their heads in the form of extreme weather phenomena and changes in weather patterns. Many electrical grids, especially in underserved communities, are ill-prepared to handle these changes. Thus far, around the world, microgrids with varying combinations of renewable energy, batteries, and back-up generators are the key to developing systems that are resilient enough to handle all the changes that the future has in store.
Photo credits: (Marii Siia / Unsplash) (South Australian State Emergency Service)