Renewable Energy for Remote Power Requirements

The invisible, odorless, tasteless gas hydrogen is widely hailed as the energy resource to drive the next "paradigm shift" to a clean energy economy, one based on a virtually limitless, homegrown supply. In the last few years, hydrogen, "H2" for short, has been billed as the "elemental" solution for just about every energy-related challenge from greenhouse gases, global warming and hydrocarbon emissions, to foreign policies entangled in Mid-East oil dependencies and the United States' import-export trade deficit.

It's a lot to ask of a lightweight.

Hydrogen claims the lowest atomic weight-one-on the periodic table of elements, the roster of basic building materials available in this universe. It resides at the opposite end of the elemental spectrum from uranium (atomic weight 92), plutonium (94) and the other "-iums" that were the centerpiece of the last big energy-based paradigm shift, nuclear power.

Hydrogen is the basic fuel for fuel cells, the clean electrical generation technology that keeps the lights on in NASA's space shuttle and could very well replace the internal combustion engine in cars and trucks of the future. Fuel cells combine hydrogen and oxygen flowing through special membranes, releasing electrons that create electric current.

For eight years, the Desert Research Institute has been experimenting with fuel cells as a cost-effective alternative to petroleum-fueled electrical generators at remote homes and businesses. DRI's research has primarily focused on the feasibility of using solar and wind power to extract hydrogen from water to run a fuel cell electrical generating system.

DRI's lead scientist on the project, Dr. Roger Jacobson, says the Institute's research has indicated that solar photovoltaic panels and wind turbines can reliably generate the power to run an electrolyzer, the device that "cracks" water into hydrogen and oxygen. But he says some near-term technological challenges continue to limit the day-to-day reliability of the fuel cells themselves, which also remain extremely expensive. A strong proponent of the idea of converting the U.S. to a hydrogen economy, Jacobson says the fuel cell glitches are the expected growing pains of an embryonic technology and will eventually be resolved.

"Someday, fuel cells will be a reliable, off-the-shelf component of just about any power application you can conceive," notes Jacobson. "They work great on the space shuttle, but not everyone has access to that level of technical support!"

So, until the time comes when consumers can grab a foolproof fuel cell at the local hardware store, Jacobson is pursuing a transitional strategy using a modified conventional internal combustion engine that retains the clean hydrogen fuel advantage. In the energy community, the concept is known as REICE, for renewable energy internal combustion engine.

With new research funding from the U.S. Department of Energy's National Renewable Energy Laboratory (NREL), Jacobson is replacing the fuel cell he's been using in DRI's Energy Laboratory with an internal combustion engine configured to run with hydrogen, or hydrogen-enriched propane. The hydrogen will still be produced using the electrolyzer powered by DRI's solar panels and 40-foot-high wind turbines humming outside the Institute's Northern Nevada Science Center in Reno.

"This approach retains the specific advantage of abundant wind and sunshine in Nevada and much of the American West, with an off-the-shelf generator technology," says Jacobson. He notes that the Nevada State Office of Energy estimates there are as many as 10,000 "off grid" sites (not connected to utility power lines) in Nevada alone that could benefit from the concept.

"There are rural spots in this state and elsewhere that face costs of up to half a million dollars to bring power in from the commercial electrical grid. REICE systems could be a very attractive and cost-effective alternative."

Jacobson says the REICE project is the third phase of a planned five-phase hydrogen energy research program. Phases I and II involved setting up the solar collectors and wind turbines at DRI in Reno and testing them for generating hydrogen for a fuel cell.

New regulating and monitoring software to operate the experimental system is being devised by Dr. Byard Wood, professor and chair of the University of Nevada, Reno's (UNR) Department of Mechanical Engineering. Also working on the project are: Dr. Melanie Wetzel, a DRI atmospheric scientist; Richard Purcell, a DRI mechanical engineer, who has been involved in the Institute's hydrogen fuels research program from the beginning; Grace Caldwell of Independent Power Corporation; and Kirk Collier of NRG, Inc. (NRG is not a set of initials for something; say it fast, and you'll understand.).

"The system has all of the components needed for a continuous power source system," adds Jacobson. "It has been designed, built, tested, and operated over the past two years. The system has two wind turbines that provide three kilowatts (3kW), and solar panels providing 2kW that will be expanded to 5kW to meet the needs of a 5-10kW internal combustion engine." Other components include an inverter, electrolyzer, batteries, hydrogen tank, programmable load bank, computer system (hardware and software), and miscellaneous sensors and electronic components.
UNR graduate students in mechanical and electrical engineering and atmospheric sciences will also be involved in the project, both for technical training and research purposes, an aspect that Jacobson, who is also DRI's academic vice president, finds particularly appealing.

When a tried and tested fuel cell is finally available, Jacobson says the componetized REICE configuration should allow the cell to replace the internal combustion engine with minor modifications.

"A diverse, flexible, and reliable combination of approaches is the best strategy for the transition to a hydrogen economy," Jacobson points out. "The greater the available, practical options that people and industry have to select from, the more quickly this transition will occur."
Hydrogen: this lightweight's a no-brainer.

-John Doherty