The Power subsystem includes three sets of 12- 3' x 5' solar panel modules mounted on two-axis tracker assemblies. The trackers follow the movement of the sun.
The solar panels feed energy to the main system building, which houses the power inverters, air compressors, water purification, electrolyzer, environmental control, and control and instrumentation equipment.
This vented steel building houses the components used to generate ammonia from nitrogen and hydrogen and part of the instrumentation and control assembly. This is the first known system to use solar energy for making ammonia. The ammonia storage tank is at the right.
Three power inverters convert direct current (DC) produced from the solar arrays to alternating current (AC), which is used by the system components, or fed to the grid when not needed by the system. The air conditioner (in the background) cools the equipment room in the summer and maintains the electrolyzer room temperature above freezing in the winter.
The equipment room contains the rack control panel (foreground, right side), used to manually set subsystem functions to Manual, Auto or Off; water deionizer (far right corner), purifies well water for use by the electrolyzer; and hydrogen valve status board on the left back wall.
The electrolyzer breaks down water into oxygen and hydrogen gas using a proton exchange membrane design.The oxygen is vented to the atmosphere and hydrogen is piped to the staging tank.
Two 5 h.p. air compressors provide air to power the hydrogen, nitrogen and mixed gases pumps and to control the isolation valves. The second compressor is housed in the tractor storage room. A refrigerant dryer and desiccant canisters (affixed to wall) remove moisture from the compressed air.
A metal hut containing the hydrogen pump assembly is in an isolated fenced area separate from the main system building.
A hydrogen pump assembly contains two air-driven hydrogen pumps. One pump compresses hydrogen into the storage tanks; the other pumps hydrogen from the storage tanks into the tractor tanks.
The controls and instrumentation assembly is located in the main system building. It directs the operation of the electrolyzer, nitrogen generator, air compressors, hydrogen fuel dispenser, hydrogen and ammonia pumps, and ammonia storage. A display panel that shows system performance information can be monitored via the Internet.
A 1000-gallon staging tank (background) stores hydrogen generated by the electrolyzer. The eight composite storage tanks contain compressed hydrogen gas.
The tractor is fueled with hydrogen using a dispenser mounted on an elevated work stand. Ammonia is pumped into the tractor ammonia tank from the ammonia storage tank.
The centerpiece of the solar-hydrogen system is a John Deere 7810 tractor outfitted with a modified Ford 460 cu. in. V-8 engine. It runs on hydrogen gas or a combination of hydrogen and ammonia.