Thread below on Green Lightning made me curious, so I did some digging. Here's what I found, let me know if anyone finds any of this to be inaccurate. I'm not claiming any experience with this product/process, or with in-furrow or foliar applications of diluted nitrate, just what I've found from looking around. Please check the math - critique welcome.

• Process:
  • Birkeland–Eyde process or similar, using electric arc to split N2 and recombine with O2, resulting in nitric acid HNO3. I'm assuming the nitric acid is then dissociated in water to get nitrate, NO3
  • Birkeland-Eyde process on Wikipedia: #mce_temp_url#
  • May have been used for nitric acid production before the Haber-Bosch process, but nitric acid is now primarily produced from ammonia from Haber-Bosch because it's less energy-intensive
  • About 34-37 kWh per lb. N in output (see Nitricity video, also matches estimate from Wikipedia process page)
    • 15 MWh per ton HNO3 = 7.5 kWh per lb HNO3 * (63/14 for percent N in nitric acid) = 34 kWh per lb N

• Others doing it:
  • Nitricity - using solar installations to fertilize small fields (25-75ac) by reacting the nitric acid with lime, creating calcium nitrate to run through irrigation water (video here: #mce_temp_url# )

• Product
  • End product appears to be nitrate and water, guessing the pH is fairly low depending on concentration of nitrate
  • According to video, maximum of 15% N by weight as nitrate, but the output can be varied
  • Nitricity indicated typically 2-3% N, or 0.17-0.25 lb/gal. To supply 175lb to a corn crop, would need 700-1000 gal/ac
  • Green Lightning numbers in the other thread would imply closer to 600 ppm N based on the energy numbers, but really need someone to test it and report back an accurate concentration of nitrate

• Economics
  • Energy cost $0.12/kWh * 35 kWh/lb = $4.20/lb N
  • Even to get to $0.50/lb N, energy cost needs to be $0.014/kWh
  • For 175lb N for corn crop, $0.12/kWh = $735/ac
  • If only using 100gal/ac at 3% N in the solution, you're applying 25lb N for about $104/ac (assuming $0.12/kWh) 
  • These numbers match with quoted in other thread - 1100 watts (=about 9600 kWh/yr = about $1200/yr) and 55,000 gal in a year comes out to 600 ppm, about 275lb N created in a year - $4.36/lb N

• "No salt"
  • I don't remember chemistry that well, so I'll defer, but seems like maybe just limited change in osmotic potential since the concentration is so low, limiting risk of root injury?