The real cost (building, etc.) will results in a way more carbon intensive production as anything else. If you consider that Denmark electricity is 66 to 75% oil/gas/coal produced, the real environmental impact of this farm will be disastrous.

The 250x less water is compared to open field production without water drop control, it will be at the same level of water consumption than all the greenhouses you see, they will not be better. This argument is as such not a good one.