On Tuesday, May 25th, the Microgrid 2021 Virtual Conference, organized by Microgrid Knowledge, hosted a panel discussion called, “Microgrids as Sustainability Heroes.” During the presentation, the panelists acknowledged the reliability issues presented by renewable energy and offered three techniques for storing energy to improve sustainability: conventional batteries, hydrogen fuel cells, and novel iron flow batteries.
The panelists were Hugh McDermott, Senior Vice President of Business Development at ESS Inc; Chris Ball, Senior Manager of Microgrids at Bloom Energy; and Norm Campbell, Manager of Federal Markets at Go Electric, Inc.
Jacqueline DeRosa, Vice President of Battery Energy Storage Systems at Ameresco, moderated the session.
The Powertrain Approach
In the first presentation, Campbell presented his company’s microgrid strategy, which he called the “Powertrain Approach.” This plan uses battery storage to facilitate fast reaction times to meet the facilities’ electricity needs when coupled with renewable sources of power, such as solar or wind energy.
Since the supply of renewable energy can be unsteady (e.g. at night or on cloudy days for solar, or on any day when the wind is variable for wind turbines), microgrids need a storage system to help balance the flow of energy and distribute it more evenly over time. Without a storage system, microgrids that exclusively use renewable energy may find themselves with more energy than demanded at some times, but lacking supply at others.
To illustrate the value of a storage system in a real-world example, Campbell described a Go Electric case study at a United States Marine Corps military tank firing range in California. Originally, the firing range was designed to run off of solar panels with a diesel generator as back-up, but with no storage system. As a result, the firing range frequently relied on the generator for power. Use of the generator quickly forced the Marine base to exceed California’s emissions requirements.
After installing a controller and a 690 kWh battery on site, the site now runs on 98% solar power, day and night, and the generators have been used 3 times in the last 14 months.
The Colors of Hydrogen
In the second segment of the session, Ball reported that hydrogen fuel cells will be the key to reducing emissions and maintaining resiliency.
By 2050, hydrogen fuel cells are predicted to supply 18% of global energy needs. They are energy dense, allow for energy to be stored for long periods of time, and are easy to transport.
According to Ball, about 95% of hydrogen produced today comes from a process called steam-methane reformation, which uses steam to break methane gas down into carbon and hydrogen, but releases carbon dioxide emissions as a by-product.
Ball described two novel approaches to hydrogen generation: green hydrogen and gold hydrogen.
Green hydrogen takes electricity generated by a renewable resource and puts it through an electrolyzer to create hydrogen. Converting electricity into easily-stored hydrogen “unlocks” solar and other renewables from the day/night cycle and from the seasonal summer/winter constraints by enabling that same energy to be used at a later point in time.
Gold hydrogen produces electricity from a “carbon-neutral gas” such as biogas a dairy or a landfill. Biogas is considered carbon-neutral because it is not a fossil fuel. When combined with a solid oxide fuel cell, which captures carbon and removes it, the electricity that comes from the fuel cell will technically be “carbon negative” because it has less carbon at the end than it did in the beginning.
The Iron Flow Battery
Finally, McDermott introduced the iron flow battery. Using only iron and salt water, this type of battery has the safest chemistry of any battery on the market and can theoretically operate indefinitely.
With an operating range of -5 to 50 degrees Celsius, ESS claims that this generation of batteries has up to 12 hours of storage capacity and each unit is 100% recyclable.
Later this year, ESS will put its technology to the test for the utility company SAESA in Patagonia, Chile. The remote grid there is largely powered by run-of-river hydroelectricity, which varies in output from season to season. Diesel generators are used every month to make up the difference when demand exceeds supply.
“The solution we came up with for this project,” McDermott explained, “was to deploy four of our containerized Energy Warehouse systems. These are fully integrated, turnkey systems that are as plug-and-play as we can possibly make them.” The system will also be backwards compatible and scalable to the individual company level.
Microgrids are already well-known for their resiliency benefits. Microgrid technology is positioned to be a key component of true zero-emission sustainability.
To learn more about how you can achieve your carbon targets, use VECKTA’s free Rapid Energy Assessor to quickly explore your onsite energy options in four simple steps.
