The consumption of electricity in water purifier is negligible as compared to any other electric equipment in your house. Aqua Ultra RO Water purifier system has a power consumption of 25 watts. It consumes 1 unit current only in 40 hours, in which time it can purify 4800 liters of drinking water. On an average, we use 20 liters of purified water per day in our house. According to this calculation, a household normally require 7300 liters of water per year. So the electric consumption will be approximately 1.52 units per year (Power consumption may vary slightly for different models).