The simplest way to make nitrogen fertilizer from excess electrical power is by electric discharge to make NOx. I remember a science museum exhibit of a simple

The simplest way to make nitrogen fertilizer from excess electrical power is by electric discharge to make NOx. I remember a science museum exhibit of a simple spark device. It was in an enclosed box to prevent gases from escaping, and the air inside was noticeably brown from all the accumulated NO2. Something like that: https://sciencedemonstrations.fas.harvard.edu/presentations/smog-bottle https://sciencedemonstrations.fas.harvard.edu/presentations/... Commercially, a similar process was used for a while a century ago, the Birkeland-Eyde process. It passed air through an arc. It was phased out because it wasn't competitive with the HB process using hydrogen from fossil fuels. https://en.wikipedia.org/wiki/Birkeland%E2%80%93Eyde_process https://en.wikipedia.org/wiki/Birkeland%E2%80%93Eyde_process