"What's needed before millions of dollars are spent to construct or renovate an existing 30-story building into a vertical farm, [Columbia University professor of public health Dickson] Despommier says, are prototypes just a few stories high. They should be built at leading agricultural universities and tinkered with until the concept is proved. 'Once it does, drive it out of the showroom and take it home,' he says.
While Despommier has won admirers around the world for his innovative thinking, skeptics still wonder how he's going to handle the problem of solar energy – bringing necessary light to the interior and lower floors of his agri-towers. 'As soon as you go vertical, you compound that problem of getting that [solar] energy to the plant,' says Gene Giacomelli, director of the Controlled Environment Agriculture Center at the University of Arizona in Tucson."
"The challenges also include finding and training indoor 'farmers' who can operate what is likely to be a complex system. 'There's nobody at the moment,' Giacomelli says. The technical problems aren't insurmountable – crops are being grown indoors at the South Pole, albeit at great expense, he says. But, he adds, 'There are many more ways to fail [at indoor agriculture] than to grow a crop correctly and succeed.'"