… Desalination plants are notoriously large electricity users. Some have natural gas pipelines running to them to fuel dedicated power plants. The company OceanWell estimates its technology will cut that electricity use by up to 40%. Its goal is to anchor an array of units 4.5 miles offshore, at a cost of $500 million to $1 billion, to deliver 60 million gallons of water per day. That’s enough for about 400,000 people. Prompted by severe water cutbacks four years ago, the Las Virgenes Municipal Water District has been working with Menlo Park-based OceanWell to develop a cheaper, less power-hungry way to turn saltwater into drinking water without sucking in tons of sea life. In a recent test at a local reservoir, it worked.