1. We have overpopulated our planet.
2. As a result we have polluted our air, water, and land.
3. The immediate problem for many of us is lack of water, drought. The west is experiencing a 1,200-year drought.
4. In the short term we may be OK but will soon need water for living and growing food.
5. Since most of the rain comes from the ocean and it isn't coming we need to get it from the ocean with desalination.
6. Desalination requires about 3.8 kilowatt-hours per thousand gallons. Large-scale desalination systems that feed into municipal water utilities, such as the Carlsbad Desalination Plant in San Diego, California, require approximately 35 MW to run and provide 50 million gallons of water supply per day (Carlsbad Desalination Project 2017).
7. The U.S. Geological Survey estimated in 2010 we'd use 42 million acre-feet per year or about 38 billion gallons per day. That includes water pumped from wells plus all of the water taken from sources such as rivers, canals, and reservoirs.
8. 38,000,000,000 / 50,000,000 = 760 desalination plants like the one in San Diego are needed to supply 100% of California's water. The requires approximately 35 x 760 = 26,000 mW of electrical power.