The U.S. Marine Corps has begun operating a $1 million CleanSpark designed and built microgrid at its Camp Pendleton base near San Diego.
The California-based microgrid developer won the the contract in 2017 as a sub-contractor to Bethel-Webcor JV, which is building a $70 million communication information system (CIS) operations complex at the base.
Deemed a net zero energy project, the microgrid incorporates both off-grid and grid-connected renewables, centered on two solar arrays — one 90 kW and another 60 kW — along with, a 400 kWh iron flow battery system. CleanSpark’s mPulse microgrid and distributed energy resources (DERs) controller provides the brains for the system.
There are two primary facets to the hybrid, net-zero energy microgrid. The first is a 100% renewable, DC-coupled, off-grid solar-plus-storage system that meets all the electricity needs of certain critical loads within a new maintenance and supply warehouse 24x7x365. The second is the broader-based C.I.S. project’s grid-connected, solar-plus-storage microgrid, which also incorporates dual-fuel, natural gas and diesel, for standby power generation.
Evaluating over 50 different technologies
The CleanSpark microgrid demonstrates the feasibility of a utility grid serving as a backup to on-site, low- or zero-carbon generation and distribution, according to Bryan Huber, CleanSpark’s chief operating officer.
“The grid will act as back-up for the critical loads, and we are able to monitor and analyze power quality, reliability, resilience and the overall performance on both the the microgrid and utility grid sides of the system,” he said.
CleanSpark evaluated more than 50 different technologies for the project, based on the design- build- best value procurement methodology used in bidding for projects at U.S. military and federal government facilities.
The military had sought a minimum amount of renewable energy as well as projected, lifetime energy cost savings. But cybersecurity was at the top of the list of design requirements. Hence, the microgrid isn’t connected to any external communications networks even though it’s based on CleanSpark’s hybrid cloud microgrid and DER monitoring and management platform, Huber explained in an interview.
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“There have been quite a few technology achievements on this project, but what excites me the most is the functional outcome. This is a hybrid zero net energy facility incorporating both off-grid and grid connected renewable generation that works together to support project economics while also providing energy security,” said Anthony Vastola, CleanSpark senior vice president.
Battery storage life-cycle analysis
CleanSpark’s Camp Pendleton microgrid has an expected life cycle of more than 20-25 years, thanks to the iron-flow battery, which eliminates the need to replace the battery packs of lithium-ion battery energy storage systems, according to Huber.
“In our life-cycle cost analysis, we found it [the iron flow battery system] to be the most economic technology for our application given first-cost and the high charge-discharge cycle environment at the site,” Huber said.
Huber also explained the importance of evaluating each technology’s performance characteristics when calculating the microgrid’s total cost of ownership.
“Flow batteries don’t degrade over time, while traditional lithium-ion solutions do. It’s also important to evaluate factors like degradation, systems losses, round-trip efficiency and each technology’s relative impacts on recurring and non-recurring operational expenses to reach accurate life-cycle cost conclusions,” he said.
Recurring costs includes preventive maintenance and cleaning of components, while non-recurring expenses include carrying out tasks such as replacement of inverters and other system components, he said.
Microgrid economics
CleanSpark microgrid controller at Camp Pendleton. Image courtesy of CleanSpark
CleanSpark estimates the microgrid will pay for itself in about 10 years. That’s longer, for various reasons, than the four to seven-year payback CleanSpark often sees for similarly sized commercial and industrial microgrids.
The longer payback is partiallly due to the inability of government facilities to leverage federal or state tax credits or other incentives. The payback also is influenced by already low energy rates available on the base.
But it’s still possible to achieve cost savings, Huber explained.
“On the microgrid side, the Marine Corps is interested in testing and evaluation of renewables-driven energy security and the possibility of eliminating some of the conventional stand-by generation and UPS (uninterruptible power supply) assets required by federal government uniform facilities criteria,” Huber said. “There’s potential for cost reductions over time, both in terms of first costs and operational expenses by using DER assets to power normal operations.”
CleanSpark’s part in development of Camp Pendleton’s CIS project builds upon previous work it has done at the Marine Corps base. In 2014 the company was a subcontractor in the deployment of a “fractal grid” for Camp Pendleton’s School of Infantry. The project integrated CleanSpark’s mPulse software platform with a variety of energy storage technologies to store solar energy produced by a solar energy system consisting of both fixed-tilt and dual-axis PV panels.
