Pressurized water has been used in many industrial processes, like oil refining, chemical and food processing, seawater desalination, etc. Much of the potential energy that is created when those liquids are pressurized is lost. And yet, a good amount of it can be re-harvested.
Energy Recovery, an equipment supplier in California, has been re-harvesting energy in desalination plants for 20 years. In the desalination plant, huge pumps push seawater through a membrane, leaving about 40% of the fluid potable, and sending the rest back to the ocean. Energy Recovery's device will re-harvest energy from the returned seawater flow and inject back to the original flow. This process helps to reduce 60% of the energy needed for pumping.
Energy Recovery has installed 14,000 devices on seven continents, and reduced about 12 billion kWh of energy per year. Tom Rooney, CEO of the company, says the plants can make back their investment in 3 to 6 years.
He sees opportunities in other industries and with municipalities. "You have a very clumsy assortment of pressure up and pressure down throughout large municipal distribution systems. There’s no question that there is an enormous opportunity to go in and harvest the pressure," he says.