Because we are in an era of light-assisted hydroponics. This is a technology for growing plants whose roots just dip in water that is doped with nutrients that the plant needs. For light–no problem–there are LED lamps that consume very little electricity.
There are companies that have put up a lettuce or spinach farm inside a de-commissioned shipping container, suitably modified, of course.
In Abu Dhabi, a company called Madar Farms has just announced that it will put up a tomato farm in a poly house in the middle of a desert. Tomatoes in a desert? Tomatoes are 80 per cent water. Still, it is worthwhile for Madar to run the farm, because of light-assisted hydroponics.
If you spend a little more capital and put in climate control systems, you can grow any plant in your backyard–climatic conditions do not matter.
There are a number of companies in India that offers this technology. One, for instance, is Thaker Agro (http://agro.thakergroup.com), based in Chennai.
Hydroponic agriculture is an exciting entrepreneurial opportunity.