Lab-grown veggies costly but have market

Vegetables can be grown year-round indoors, in "plant factories" that look a lot like laboratories - without a farm's heavy dependence on water supplies, soil, weather and manual labor.

But plant factories require lots of energy, something that has to change before they can become commonplace, scientists say.

Plant factories do not rely on sunshine. Rather, vegetables are grown in special hydroponic nutrient solutions. All conditions are carefully controlled, and that draws energy.