I believe there is already one in Japan: http://www.gereports.com/post/91250246340/lettuce-see-the-future-led-lighting-helps-farming

Water recycling and reduced labour costs are the facility’s two most significant selling points. Spread says it is able to recycle 98 per cent of the water used for cultivation, while cutting labour costs by 50 per cent through automation. The facility also uses state-of-the-art LED lighting to minimize electricity costs. The company says the technology can be utilized worldwide. Regions such as Japan with little land available for agriculture are likely to be the early adopters of the technology, however.

This is super cool.

They've been playing a lot of Harvest Moon.

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