This is a desert/ocean idea. It involves a profound study at first.

You know how to make electrical discharges, but you haven't found a use for this yet. 

You would try to find if electrical discharges are any good at changing substances. Honestly, the quick search I did on this didn't yield concrete results. You would investigate if discharging a solution or gas repeatedly alters it somehow, and produces substances of commercial value.

You also could investigate if a metal alloy gets hardened after being subjected to these electrical discharges.

Finally, more on the environmental side, you could see if it produces ozone.

Once you find an application, if you find one, you can build several zapping units and spread them in a desert. 

These units would have a solar pannel, that would store energy in an capacitor or battery. The solar pannels charge the batteries or capacitors, and when maximum charge is attained, a discharge happens.

All day long, these units dischange into your material, altering it. From time to time you would collect the final produts, and replenish the reactants.