Domestic immersion heaters used for heating cold water are characterized by an electrical resistance heating element, which is encased in a tube and directly placed in it. The most common method for heating cold water is the use of portable immersion rod water heater in an open bucket operating in operator control without a controller unit (thermostat). This paper performs an experimental evaluation of portable Modifed conventional buckets of 10 l capacity. Out of ten portable Modifed storages, the best three cases are discussed: non-insulated Open Plastic bucket (OPB), non-insulated plastic bucket top surface covered with a transparent cover (CPB), and insulated plastic bucket closed with a transparent cover (ICPB). Maximum temperatures arising after two hours during OPB, CPB, and ICPB are 29. 82%, 47. 36%, and 21. 49%, respectively, compared to the initial temperatures (22. 8 C). At 14: 45 hour, CPB temperature reaches 35. 6 C, which is 17. 88% and 23. 61% higher than OPB and ICPB units. Due to the application of solar energy in CPB at 35{50 C, net saving increased by 12. 34%, 25. 76%, 40. 73%, 57. 93%, 76. 45%, and 97. 18% from 2017 to 2022 as compared to the saving in 2016.