That means building futuristic structures that use wastewater and solar power to produce hydroponic (grown in a nutrient-rich water, without soil) and aeroponic (grown in water-saturated air) crops.
The real value of renewable energy lies not in low costs (though lower costs are certainly a laudable development), but in its environmental benefits the cleaner air, water, and land that we all enjoy, and the hope of a future without catastrophic climate change.