Researchers at University of California, Riverside, are testing a control system for a solar community microgrid that will decide how to dispatch assets — reaping energy savings and perhaps generating income.
The Bourns College of Engineering research team is working on a power system for a microgrid located at the Chemehuevi Indian Tribe reservation near Lake Havasu, Calif. The microgrid will serve a community center and integrate solar, battery storage, data analytics and smart energy controls.
The community center, now powered by diesel when there’s a blackout, is an emergency response center for people of all ages during blackouts, which occur fairly often because the reservation is located at the end of a transmission line, said Alfredo Martinez-Morales, managing director, research faculty at the Southern California-Research Initiative for Solar Energy University of California (UC), Riverside.
Located in the exposed region of the Mohave Desert, the community center experiences blackouts from high winds, bird strikes and the monsoon season.
The microgrid was installed in September and October by GRID Alternatives’ Inland Empire staff and two tribal job trainees.
The UC students have developed code to manage the assets, said Martinez-Morales. “We take into account historical data and real-time data. We look at solar energy generation and production, the building load, the state of charge of the battery bank, and then by looking at this, we predict what should be the next action we should take.”
For example, the system might decide whether to provide utility power to the community center to offset a deficit of solar energy. It might decide whether solar or battery power should be sent to the grid, he said.
Industry contributes to project
A number of industry members, along with the California Energy Commission, are contributing to the project. The 90-kW solar carport PV system was supplied by SunPower. A 25 kW/125 kWh Primus Power flow battery energy storage system was provided by Primus Power. En Sync Energy Systems’ advanced Matrix Energy Management and DER Flex technologies will provide system integration.
The California Energy Commission supplied a $2.3 million grant for the project, much of which aims to fund research, he said.
Researchers will complement the En Sync system system integration with their own program written by students. They’ll also compare the two programs, said Martinez-Morales.
En Sync’s Matrix system allows users to connect multiple DC assets into a smart inverter and optimize and meet electrical load as needed, he said.
“We will use this and compare it to our own algorithm” said Martinez-Morales.
Researchers are now negotiating an agreement with Southern California Edison and hoping to participate in special programs— such as demand response — that allow the microgrid to reap both savings and income, he said.
Four energy management strategies
By Krisana Antharith/Shutterstock.com
The microgrid will implement four energy management strategies: peak reduction, load shifting, demand response, and storage-to-grid activities. The first two will benefit the community center.
The second two, on the other hand, are designed to benefit the utility and generate income for the project participants, said Martinez-Morales. With this goal, the microgrid project may face challenges other microgrid and storage projects are now grappling with: receiving compensation for the benefits storage and microgrids can provide to the grid.
The ability of the demand response and storage-to-grid programs to generate income depends on the kind of deal the project can strike with Southern California Edison, said Martinez-Morales.
“It really depends on whether we can be enlisted officially and be compensated or if this will be seen as a demonstration project,” he said.
The peak reduction and load shifting programs are expected to yield significant savings for the community center, he said.
The community center uses about 164,400 kWh annually, and has a 64 kW peak demand, he said. The research/industry team expects to significantly reduce that peak. Meanwhile, researchers expect to yield additional savings by replacing diesel with solar-plus-storage. Martinez-Morales estimated that the system should provide about 85 percent of the energy demand.
Future solar community microgrid projects
GRID Alternatives has installed over 80 residential systems on Chemehuevi homes to-date, and trained 20 members in solar installation.
Lessons from the three-year project are expected to serve as a model for similar solar community microgrid initiatives.
The CEC has plans to invest $44 million in microgrid projects in 2018, and is concentrating on tribal and disadvantaged communities. Mike Gravely, a spokesman for the CEC, said the commission is now evaluating microgrid proposals and developing project scoring criteria that will be released publicly next month.
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