) than other versions (like the phosphoric acid version at 150°C. & the molten carbonate version at 800°C.). This Energenics version puts out 750
Watts continuously. The Energenics Company is working hand-in-hand with the Schatz project in research and development on retrieving energy stored in hydrogen.
The Inverter
We expected to find a high-dollar, super inverter in such an advanced system. Instead, we found the same garden variety Trace Inverter used in thousands of home power households. A Trace 2032 Inverter hummed happily on the wall. It doesn't care if its DC power comes directly from the PV array during the day, or from the fuel cell at night. The Trace is very democratic, and very reliable; it keeps the fish alive & happy.
Above: Peter Lehman stands beside the oxygen storage System Control and Instrumentation tank. Behind him are two hydrogen tanks.
The instrumentation and control on the Schatz project are determining the amount of gas in the tank.
extensive. After all, the major product here is information.
The Fuel Cell
The system is monitored by computers at every stage of The fuel cell reverses the process carried on in the the process. Seven optoisolated, analog to digital electrolyzer and converts the stored hydrogen and oxygen converter boards talk to the system's two Macintosh gases back into water. This process also releases DC
computers.
electricity at the same time. On the day we visited the System control is accomplished by shorting out individual Schatz project, the fuel cell had been returned to its sub–arrays. This is accomplished by computers manufacturer for testing. When installed in the system, controlling 30 Ampere relays. A bank of NIFE Sunica the fuel cell will enable the stored gases to be directly and nickel-cadmium cells is floated on the array to act as a Home Power #22 • April / May 1991
29
PV/Hydrogen
the crew are working on. In the future, when we're using hydrogen for power storage, then it will be because folks like the Humboldt crew did their work right now.
Hopelessly Hi-Tech?
Not on your life. After a morning of sunshine hydrogen flowing through polished stainless steel, we visited another project at Humboldt State– the Campus Center for Appropriate Technology (CCAT). CCAT makes renewable energy real right now. The CCAT building uses PVs and wind for power (battery storage here), solar hot water, efficient appliances, a solar greenhouse providing space heat as well as fresh veggies, and even composting toilets. The CCAT building houses students in the Environmental Resources Engineering program and gives them the same hands-on experiences lived by home power producers. These students get to live on Above: Peter Lehman explains the system. The vacant renewable power on a daily basis, learn about the space in the rack holds the fuel cell.
systems involved, and create their own variations. They
"flywheel" to prevent constant relay switching during are an intense crew. I could see their commitment from power surges.
the well–thumbed copies of Home Power on their The System's Safety
bookshelves. The students at CCAT were not only A clear Lucite cage contains all hydrogen handling learning new things, but are willing to share what they components. This cage vents outside and operates at have learned. They have promised to write about their less air pressure than the room in which it lives. Any experiences in the next issue of Home Power.
hydrogen leaks are instantly detected by ultra sensitive Conclusion
hydrogen sniffers and the system is automatically shut Hydrogen storage is coming. The students and faculty at down. All piping within the system is stainless steel. The Humboldt State are joyously pushing the edge of the electrical components are protected with every known energy envelope. When I was in school the only things fuse, breaker, and disconnect. The entire system will not under discussion were building better bombs and nukes only meet the NEC, but it will make the most paranoid too cheap to meter. To find an established center of electrical inspector feel safe. This PV/hydrogen learning with a heart and an eye to our future gives me installation is safer than your kitchen stove or hot water great hope. As I said, "It makes me want to go back to heater.
school."
The Reasons Why
Access
The first reason is to learn how to store PV produced Dr. Peter Lehman, Director of the Schatz Solar Hydrogen power as hydrogen. The second reason is to learn how to Project, Environmental Resources Engineering Dept., retrieve this stored energy through a fuel cell. The Schatz Humboldt State University, Arcata, CA 95521 •
project is research and development in the use of solar hydrogen.
The project is funded by Mr. L.W. Schatz, president of General Plastics Manufacturing Company of Tacoma, WA. My compliments to Mr. Schatz for looking far beyond the next quarter's profits and into an energy future we can all share.
Hydrogen Home Power?
Well, not yet. But, Peter Lehman and his compatriots are working on it. This system is far too costly and complex for basic home power right now. That's what Peter and 30
Home Power #22 • April / May 1991