I did! Transportation only accounted for 22% of the cost of a head of lettuce in my local Walmart, which wasn't really enough margin to justify the cost of the artifical lighting necessary to grow in Canada (even in dense southeastern Ontario). I think right now the most realistic application of these technologies is for premium products that are branded as such, like hot house tomatoes or living plants that can command 2-5x the standard barebones import price. Do you have different data?
The only way it would be comparable to CA flown in lettuce is the greenhouse/vertical farms are fully automated and there is a super short supply chain and absolutely no wastage. This can be achieved by supplying to local markets which would shorten supply chain. But the scale would have to be massive to make a buck out of this.
Automated greenhouses must also look into growing underground. In tunnels beneath or near water treatment plants or anywhere where there is steam.
Further, energy will always be an issue. There are two ways to go about it. Cheap electricity by going nuclear. Or advances in material sciences to develop new kinds of indoor lights/batteries or greenhouse material that can help with light/heat/thermal insulation.(one company is doing it with quantum/nano dots as greenhouse material. ETFE can be a better material than greenhouse plastic or glasshouses)
