You're right, industrial rates in Anchorage are around 11ct/kWh. Also, it's possible to use LEDs tuned to the absorbtion spectra of chlorophyll, as you say. I

You're right, industrial rates in Anchorage are around 11ct/kWh. Also, it's possible to use LEDs tuned to the absorbtion spectra of chlorophyll, as you say. If my back of the envelope calculations above are wrong by more than an order of magnitude, it might in fact be a commercially viable option for farming. Is this [1] the Singaporean project you were refering to? They probably don't need heating, but nonetheless their quoted energy needs of 3$/month/structure are astonishingly low. [1] http://permaculturenews.org/2014/07/25/vertical-farming-singapores-solution-feed-local-urban-population/ http://permaculturenews.org/2014/07/25/vertical-farming-sing...