Fire departments in Madison, Wisconsin, Los Angeles, California, and Mesa, Arizona, have electric vehicles (EV), but they had to install expensive, 480-volt, three-phase power systems to charge the EVs.
There’s a better option – and it can help provide energy resilience during emergencies for mission-critical municipal agencies, said Michael Benson, a former fire chief who is co-owner of Command Consulting, LLC, a consulting group that focuses on electrification. Benson’s goal is to help municipalities understand the benefits of electrifying their fleets and charging the EVs with microgrids.
“There’s no way to have robust charging without a microgrid,” he said.
Firehouse microgrids in Portland, Oregon, and Fremont, California
Firehouse microgrids are not new. For example, the city of Portland, with financial support from Portland General Electric, installed a fire station microgrid that not only ensures power for crucial services but also trains emergency workers in the use of microgrids.
The city of Fremont, California, installed microgrids at three of its fire stations. The city was interested in getting clean and renewable power and felt that the battery integration would provide additional utility bill savings as well as energy resilience. The microgrids provide backup power when the grid goes down, and they also supply most of the power for the three fire stations, using the microgrids’ solar panels or batteries charged with solar.
Benson wants municipalities to take this movement a step further. They need to electrify their fleets – including their firetrucks – and use “mission-critical microgrids” to charge the EVs, lower costs and reduce polluting emissions. The microgrids would also provide energy resilience to support critical services, he said.
The importance of mission-critical EV charging
As municipalities add EVs – including electric firetrucks – they’ll need to have enough power available to quickly charge their vehicles, Benson said. If they don’t, injured or sick people waiting for a charged vehicle to arrive may not survive.
“You need both EVs and EV charging and the only way to make it work is with a microgrid,” he said.
A top priority is having the ability to quickly charge EVs so fire, emergency and police first responders can serve the community when they’re needed.
For example, an electric firetruck would require 1 MW of charging and 0.8 MWh of storage, Benson said. This is needed to meet the 15-minute periods when the vehicles need to be quickly recharged that might occur 12 to 15 times a year.
Refueling firetrucks can take up to 30 minutes
“When firefighters all go to a big fire, they come back and decontaminate, they need to refuel. Typically, the truck drivers stop at diesel pumps and fill up the truck so that it’s out of service for 15 to 30 minutes,” Benson said. Refueling EVs with a microgrid takes 15 minutes and avoids diesel emissions.
Six electric patrol cars with 80-kWh battery packs would need six 256-kWh fast chargers and, if they’re all plugged in at the same time, they would need a megawatt charging system and about 800 kWh of storage, Benson said.
Right now, most firetrucks use diesel fuel, sometimes as electric-diesel hybrids. Benson expects new technologies and chemistries to be available soon, possibly in the form of a solid-state, 500-mile battery that would require no diesel backup.
Selling microgrid services to the grid
When municipalities are not using microgrids to meet peak charging demand, they could sell energy or services to the grid. In addition, cities and towns could use the large batteries in the EVs – if the EVs have bidirectional charging capability – as distributed energy resources (DERs). The microgrids, too, could serve as DERs.
“Because of the extra power and energy in the microgrid, it could be used for other purposes: community resilience, backup power for a facility, in addition to charging an electric firetruck,” said Benson. “You don’t need the microgrid except during momentary peak demand times for 15 minutes,” he said.
And the microgrids will boost resilience during disasters.
Microgrids can help out during emergencies
“Mission-critical microgrids as distributed energy resources will improve disaster resilience by supporting EVs during evacuations from hurricane- or other disaster-affected areas,” said Benson. “They would supplement or replace public EV charging systems.” The microgrids might be the only EV infrastructure available during a disaster like Superstorm Sandy, he added.
The innovative mission-critical microgrid deployed by Montgomery County, Maryland, illustrates the benefits of embracing electrification and microgrids, Benson said.
The Brookville Smart Energy Bus Depot in Montgomery County, under a public-private partnership with AlphaStruxure, was designed, built and financed by AlphaStruxure as well as owned and operated by AlphaStruxure. The county made no upfront payments and signed a long-term energy-as-a-service agreement with AlphaStruxure. The 6.5-MW microgrid can support 70 electric buses and integrates solar photovoltaic canopies, renewable natural gas-ready on-site generation, energy storage, microgrid controls and electric bus chargers. This ensures the fleet will continue to operate during utility outages.
Montgomery County bus depot leads the way
“Montgomery County has shown other counties how to deploy mission-critical microgrids,” said Benson.
In addition to looking into energy-as-a-service options, local governments electrifying their fleets should keep an eye on opportunities to replace diesel motors with fuel cells.
Excess power from microgrids can be used for making green hydrogen from water using the electrolysis devices used to create hydrogen.
“Hydrogen can be stored right in the vehicles, which reduces complexity and provides increased efficiency,” Benson said. What’s more, oxygen produced as a byproduct of hydrolysis can be stored and used by first responders who already store, transport and use oxygen for patients, he added.
One city could realize $8.1 million in savings over 30 years
Municipalities can reap millions of dollars in savings if they electrify their fleets and charge the vehicles with microgids, Benson said.
A study Benson completed for one city found that it will realize $8.1 million of value over 30 years by electrifying vehicles and charging with a microgrid.
The study found that the city will save $3.5 million in direct savings – $1.4 million by replacing its fleet with EVs and $2.1 million by using renewable energy microgrids. The city would also achieve $4.6 million in avoided costs.
Energy-as-a-service and charging-as-a-service financing utilizing power purchase agreements helps make the savings possible, Benson said.
Microgrids ensure EVs are ready
Microgrids not only provide savings for those electrifying their fleets but the technology can also help improve public safety.
To date, more than 60 law enforcement agencies around the country have EVs in their fleets. With microgrids, fleet owners can ensure the EVs are charged when needed and ready to provide resilience, reduced carbon emissions and cost savings to the larger community.
