The microgrid kit developed under the U.S. Army's RENEWS project includes compact batteries, foldable sheets of solar panels and a collapsible wind turbine. (U.S. ARMY)
U.S. Army researchers have begun field-testing a new generation of a renewable power source that could ease the pressure on soldiers who depend on conventional fuel to power their radios, laptops and GPS units.
Driven by sun and wind, these “microgrids” could ease the logistical burden of transporting fossil fuels to remote areas. The systems are relatively portable compared to traditional generators: A microgrid weighs about 100 pounds packed into two hardened transit cases weighing 70 pounds each.
The kit includes compact batteries, foldable sheets of solar panels and a collapsible wind turbine.
Researchers have begun sending units for operational assessments at the National Training Center in Fort Irwin, Calif., and in U.S. Africa Command, said Marnie de Jong, an electrical engineer with the communications electronics center at the U.S. Army Research, Development and Engineering Command.
Work began in 2009 on the project, known as Reusing Existing Natural Energy from Wind and Solar (RENEWS).
The system is designed to power two or three laptops continuously, as long as there is power available to drive the solar panels or wind turbine, de Jong said. When the sun is down and the wind drops, the system will be able to provide energy from storage cells for about five hours.
Developers say the new energy source could help reduce over-the-road traffic necessary to supply generators in the field, a casualty-ridden enterprise the military has been looking to address.
“Fuel consumption is a big problem in the field right now. It’s one of the major issues that we have,” de Jong said. With its small size and local power generation, the microgrid “reduces the logistical burdens, as well as the safety concerns of transport.”
The technology also could reduce the burden from existing generators, thus reducing the need for maintenance and spare parts, mechanical engineer Mike Zalewski said.
Researchers have faced some technical challenges along the way, for example in the development of a mast that could support a wind turbine in rugged conditions. They hit upon carbon fiber as the ideal material to construct a mast that weighs just 17 pounds, yet stands roughly 16 feet tall.
Other pieces have fallen into place more easily.
“If you look on the commercial side, you see these things everywhere, so the principles of the technology are really mature,” de Jong said.
“What we have done here is to make those things very lightweight and portable, and then we also made them tactically operational,” meaning they can operate under harsh field conditions, she said.
In conjunction with RENEWS, the researchers are developing a tool to make energy systems more interoperable, a system dubbed Renewable Energy for Distributed Undersupplied Command Environments (REDUCE).
Interoperability can be an issue in power generation, as different systems might require different cables and diverse connectors to attach batteries. The REDUCE program is an effort to standardize those connections to make power more readily available.
“Right now, you never know exactly what the soldier is going to be using the system for, and there is a lot of variability, so you need something robust enough to handle all those different systems,” de Jong said. “The goal is to get all the different systems in the field to work together.”