It’s not surprising that military microgrids in the US demonstrate some of the most sophisticated and innovative uses of distributed energy. After all, they are designed with national security in mind.
As such, they serve as a learning ground for microgrids developed for the civilian sector. Here we offer a look at four military microgrids that stand out.
San Diego’s Miramar microgrid
The Marine Corps Air Station Miramar, San Diego is an evolving project, launched with $20 million from Congress.
It includes numerous resources, among them 1.3 MW of solar PV, a 3.2 MW landfill gas project, a 6.45 MW diesel and natural gas plant, 1.6 MW HVAC demand response, 157 kW thermal energy storage, EV charging station control, 3 MW ff energy storage (microgrid system level), 390 kW building level energy storage (Lithium-ion and zinc flow batteries and vehicle-to-grid bi-directional hybrid vans), SCADA system upgrades, an advanced microgrid control system and an Energy and Water Operations Center (EWOC).
In addition to supplying redundant power, the microgrid is designed to help green the base’s operations, bolster cybersecurity, reduce demand charges, manage overall energy load, participate in demand response and provide grid services.
One of its most recent innovations combines landfill gas and energy storage to reduce fossil fuel use. The effort also offers a way to address the worldwide problem of waste management. The world generates about 2.01 billion tons of municipal waste, a figure that the World Bank sees growing 70% over the next three decades
Like other renewable fuels, landfill gas is not always available when needed. Its variability can be a problem when a microgrid islands from the main grid and relies solely on its own generators.
“One of the challenges associated with landfill gas is the uncertain nature of its output. It’s not like burning natural gas that has been provided by a utility, filtered and cleaned and the same pressure at all times,” said Mark Feasel, vice president, electric utility segment & smart grid at Schneider Electric, which worked on the project in conjunction with Black & Veatch.
By coupling battery energy storage system with landfill gas, Miramar’s design offers a solution. The battery can maintain stable bus, frequency and voltage, even isolated from the grid.
Funds for the energy storage came from a $3.9 million grant from the California Energy Commission.
Providing benefits beyond the base
Located on Cape Cod, Mass., the Otis Air National Guard Base project hopes to serve as a model of how military microgrids can provide economic benefits to both the base and the regional grid.
Otis is doing so by participating in a utility demand response program and providing frequency service to ISO New England, the regional grid operator.
The microgrid can meet all of the military facility’s power needs while islanded. It includes a microgrid controller by Raytheon, a 1.5 MW wind turbine, a 1.6 MW diesel back-up generator, a 1.6 MW/1.2 MWh lead-acid battery energy storage and management system.
Also of note, the Otis microgrid is:
- The first microgrid in the eastern Massachusetts territory of local utility Eversource and within ISO New England to provide ancillary services
- The first microgrid to integrate enough wind power and batteries to meet 100% of the electricity needs, 24×7, at a military base or defense facility
- The first US military facility connected to an independent system operator
- The first microgrid to leverage a battery-based energy storage system to form a base-wide microgrid completely independent from any utility grid or other external power provider
The team designed the microgrid so that it will pay for itself in five years or less. It has an estimated savings-to-investment ratio of 2:1 over its 20 year life cycle.
The Otis microgrid was funded by a $5.7 million grant from the Environmental Security Technology Certification Program, a Department of Defense effort to support leading edge, environmentally friendly energy technology for the military. The state of Massachusetts contributed another $1 million.
Hardened to storms and earthquakes: Parris Island microgrid
Developed by Ameresco, the 10-MW microgrid is designed to withstand storms and earthquakes at the US Marine Corps Recruit Depot (MCRD) Parris Island, South Carolina.
The $91 million project, which features energy efficiency and renewables, includes a microgrid to keep power flowing on the 8000-acre base so that training can continue. The Marine Corps trains about 20,000 recruits annually on Parris Island.
Renewable microgrids also offer a route to curb military use of petroleum. The US Department of Defense is the single largest consumer of petroleum in the world. Navigant Research estimates that the military could save $8-$20 billion over the next 20 years by shifting from a reliance on backup diesel generators to large-scale microgrids.
On Parris Island, the military is expected to save $6.9 million in annual utility and operational costs and reduce utility energy demand by 75%, and water consumption by 25%. Its energy makeover includes:
- Replacement of a power plant with 3.5 MW of combined heat and power and three diesel backup generators
- 20,000 solar modules, installed at carport and ground-mount sites, which provide 5.5 MW. The solar panels provide shelter for more than 500 parking spaces.
- Batteries totalling 4 MW/8 MWh
- Intelligent microgrid controls to assure power supply in the event of central grid outages
The military paid no upfront capital costs, a common financial arrangement for military microgrids. This was achieved via an energy savings performance contract with Ameresco.
Under the contract, Ameresco will operate and maintain the military microgrid and its energy assets for 22 years.
A microgrid on the move
Go Electric designs military microgrids unlike others described here. They are on wheels and come in a box that four people can lift and commission — and then move, if needed.
The mobile technology is particularly suited for remote and perhaps temporary military installations.
“Our standard solution is a turnkey microgrid. Most of what we’ve done has been at stationary buildings and bases. This is a turnkey microgrid on wheels,” said Lisa Laughner, president and CEO, Go Electric, which earlier this year was acquired by Saft, a multinational battery energy storage company owned by Total.
Go Electric was awarded an $887,535 Small Business Innovation Research Rapid Innovation Fund contract to develop a modular microgrid for the US Africa Command (Africom). The aim is to create a microgrid that can handle the harsh environments of the front lines and also be flexible enough to incorporate numerous assets, some of them already on site.
Africom has a need for mobile power for numerous purposes, said Laughner. The first is for operating bases in Africa. Another is for disaster relief.
“If a remote community needs a power generating system set up with lots of different kinds of power assets, this could be used as disaster relief or to get a remote area electrified until a permanent solution can come in,” she said.
Learn more on the Microgrid Knowledge military microgrid channel.