Net Zero Water Use At Data Centers

Abstract

The growing demand for cloud storage has resulted in major growth for the data center industry worldwide. A popular method for heat removal in large data centers is through the cycling of high volumes of water from cooling towers to data centers. This recirculation process continues until fouling in the cooling tower occurs, primarily from CaCO3 and CaSO4 after which the water is disposed. It is estimated that for the average 500-ton cooling tower approximately 14.8 million liters of water per year are wasted without being reclaimed. This amounts to 40,800 liters per day of wastewater concentrate commonly referred to as Cooling Tower Blowdown Water (CTBD). The NetZero system specializes in water recovery and wastewater minimization for existing industrial plants, specifically data centers. The NetZero system is specifically designed for a plant with a 500-ton cooling tower capacity, with an 80% wastewater recovery target. This is an estimated yearly reduction of about 11.8 million gallons of water and 34,000 metric tons a carbon dioxide emission. The NetZero system uses sixty-eight membrane distillation units in parallel to purify the water for reuse. The levelized cost of water to produce 1 m3 is estimated to be $4.74 for our system.