Water is fundamental for all life. The combination of increasing global population, the consequent growth in demand for fresh water in agriculture and industrial sectors, and the impacts of climate change means that the demand for freshwater is rapidly outpacing supply. This imbalance is leading to a growing number of water-stressed regions worldwide.
According to the World Resources Institute's Aqueduct project study, many parts of the world will experience large-scale water stress in the coming decades. On the current trajectory, it is estimated that by 2040, most parts of India could reach the highest levels of water stress (40% to 80% water stress). These looming water shortages will profoundly affect agriculture, threatening the nation's food security. Furthermore, UN experts project a 20% reduction in renewable water resources for every 1°C increase in the global average temperature. Global warming is expected to both increase the number of water-stressed areas and intensify water stress in already affected regions.
Industrial Water Consumption and Cooling Towers
Available statistics indicate that industrial water consumption in India accounts for approximately 12% of the overall water consumption. Among industrial water users, thermal power plants are the largest consumers, accounting for 70% of the total industrial water use. The majority of water consumption in a thermal power plant occurs within its cooling towers.
Cooling towers operate on the principle of evaporative cooling. During this process, a portion of the circulating water evaporates, and as the water evaporates, it draws heat from the surroundings, thereby cooling the remaining water. For a typical cooling tower, the evaporation rate is about 1.5% of the cooling water circulation. For example, a 500 MW coal-based thermal power plant in India with a Cycle of Concentration (COC) of 4 would require a makeup water supply of 1400 M3/hr, comprising 1050 M3/hr for evaporation and 350 M3/hr for blowdown loss.
Limitations of Current Water Conservation Technologies
Currently, the primary technology available for conserving water in thermal power plant cooling systems is the adoption of Air Cooled Condensers (ACCs). However, very few thermal power plants have implemented this technology due to the prohibitively high Capital Expenditure (CAPEX) costs. Moreover, ACCs lead to reduced power generation because of an increase in the power plant's heat rate. A typical loss of power can be about 7%. This means a 500 MW thermal power plant equipped with an air-cooled condenser would only generate 465 MW. To achieve the full 500 MW output, an additional 7% more coal must be burned, leading to increased CO2 emissions. For a typical power plant with a wet cooling tower, CO2 emissions are around 0.9 kg/KWh, whereas with an air-cooled condenser, CO2 emissions increase to 0.96 kg/KWh.
First ESCO's AquaStatic Plume Capture System
FirstESCO's Experimental lab-scale prototype capturing simulated water plumes (March 29, 2024)
At First ESCO, we have developed an innovative technology to recover and recycle water from cooling tower plumes. Our technology involves ionizing the nanoscale water particles in the plumes and then agglomerating these particles to form water droplets, enabling efficient water recovery. Using this breakthrough technology, we can recycle up to 90% of the water evaporated in cooling towers.
FirstESCO's pilot-scale prototype of AquaStatic Plume Capture System.
Furthermore, our proprietary SAB-ZLD (Solvent-based Zero Liquid Discharge) technology can be effectively used to recycle cooling tower and boiler blowdown water. Read more about our SAB-ZLD Technology
