Producing 60 tons of catfish every day on average, Dai Thanh have to use boiled water at 600oC to clean all the equipment and production lines to ensure the quality of the export products as the amount of waste such as fat and blood from production is very high. Installing the solar water boiling system helps keep the equipment and buildings as clean and hygienic as required.

Water is heated at 28 to 60oC by the solar energy system, then put into containers to use in the fish fat cleaning process, said Mr. Tran Van Tung, deputy director. If heating water by conventional electric water boilers, the company has to use 36kWh for 1 m3 of water, whereas they only need 2 kWh for water pumping if they use the solar boiler. Using 13 cubic meters per day, the company saves 442 kWh, in other words VND442,000/day. With the working frequency of 3 shifts/day, and more than 300 days/year, estimatedly each year the company can save up to VND150 million.

However, with this solar water boiler system, the investment cost is relatively high, about VND30 million/cubic meter, nearly 10 times by the conventional method.

However, according to the representatives of Nam Viet Energy and Refrigeration JSC (the supplier), a solar water boiler system with capacity of 13,000 liters only needs a 200-square-meter covered area. Saving an average 500 kWh every day, companies can return capital after 2.5 years, and from then can use for free for 20 years. Therefore, despite a high initial investment cost, the long term effect makes these solar water boilers worth considering.

By  Tran Quy