Vertical farming is often hailed as the future of agriculture, but my neighbor tried one of those indoor lettuce towers and his electric bill doubled for a few sad leaves. Hydroponics and LED lighting sound efficient until you calculate the kilowatt hours per kilogram, especially in regions with dirty grids. I'm not convinced we can replace soil-based farming for staple crops like wheat or rice, no matter how many climate-controlled warehouses we build. Can vertical farms ever be more than a niche for expensive greens and herbs in wealthy cities?