Given the substantial energy consumption, finding solutions to optimize electricity use, reduce costs, and enhance product competitiveness has been a constant concern for The Vissai Cement Group. One solution adopted by the company is investing in waste heat recovery power generation technology.

The waste heat recovery power generation system is an advanced European technology widely applied across various industries. The Vissai Cement Group implemented and integrated this technology during the construction of Do Luong Cement Plant, where it has been operating stably since early 2017.

The system works by recovering heat from exhaust gases and waste air from the clinker production line. The recovered heat generates steam, which powers turbines to produce electricity for the plant's operations. This reduces production costs and protects the environment. After passing through the waste heat recovery system, the exhaust gases are cleaned of dust and cooled before being released into the atmosphere.

This is currently the most advanced and environmentally friendly solution in cement production technology. Statistics show that the system generates over 100 million kWh annually, supplying up to 39% of Đô Lương Cement Plant’s total electricity consumption.

To reduce electricity consumption, the waste heat system was installed and operated to recover heat from the kiln system for power generation. Heat is recovered from two locations: the hot air from clinker cooling (AQC kiln) and the hot air from the preheater tower (SP kiln) on both production lines. This solution saved VND 159 billion in 2023.

Additionally, the plant installed inverters to control the motors of two ID fans (6.0 KV-3150 Kw), regulating the airflow by adjusting the fan speed instead of using throttling valves or hydraulic couplings as before. As a result, the electricity consumption of the raw mill fan decreased by 25%.

According to calculations, in 2024, with a projected clinker output of 4,460,000 tons, the electricity saved (compared to not installing inverters) will amount to 8,920,000 kWh, equivalent to VND 26.7 billion.

Furthermore, the electricity consumption of the coal mill fan decreased by 41% after the inverter installation. In 2024, with the same clinker output, this will save 1,962,400 kWh, equivalent to VND 2.94 billion.

Alongside investing in waste heat recovery technology, Do Luong Cement Plant will launch a solar power generation system in May 2024. The system utilizes rooftop space in raw material warehouses, generating an average of 170 MWh per month, accounting for approximately 0.8% of the plant's total electricity consumption.

Mr. Pham Xuan Khanh, Deputy Director of Production at Song Lam Cement Joint Stock Company, shared: "We have optimized equipment operations by rotating device shutdowns during peak hours to reduce electricity and production costs per unit of clinker. This has helped us lower production costs due to the difference in electricity prices during peak, off-peak, and normal hours, while also reducing peak-hour electricity load on the national grid. This solution has saved VND 14.5 billion in costs (the price difference in purchasing electricity between peak and normal hours). We also control lighting equipment operations by replacing low-efficiency light bulbs with higher-efficiency ones. For new installations or replacements of damaged lights, we exclusively use LED bulbs. A schedule for switching lights on and off has been established for various areas within the plant."

Air conditioning control solutions have also been implemented. Temperature settings in power stations and administrative areas are regulated between 26°C and 28°C. Rooms with air conditioning are sealed, natural ventilation is utilized, and air conditioners are only used after 8 a.m. and turned off 15 minutes before the end of working hours in administrative areas. Air conditioners are turned off when not in use, and regular maintenance is carried out to replace low-efficiency equipment.

The company has improved production processes to save energy and reduce greenhouse gas emissions. An energy management team has been established to monitor the plant's energy consumption. Once every three years, the plant hires an energy auditing firm to review its energy consumption. This helps identify deficiencies in energy management, which are then addressed to reduce power consumption.

Equipment optimization measures include: periodic maintenance of equipment, replacing outdated and energy-intensive devices with advanced energy-efficient ones, shutting down devices during peak hours to reduce electricity costs and avoid overloading the grid, inspecting and repairing areas of energy and heat leakage within the plant, and continuously improving equipment and production processes to lower energy consumption.

By implementing an energy-efficient usage plan, Song Lam Cement Joint Stock Company has achieved significant economic benefits and contributed to energy conservation in society. According to Deputy Director of Production Phạm Xuân Khánh, by applying new technologies and management methods, the plant has saved 131,533,255 kWh of electricity since 2023, equivalent to VND 195 billion.

The plant has also developed a comprehensive energy management system, including: Issuing an energy policy for the plant; Establishing an energy management committee comprising members from various departments and workshops; Employing certified energy managers (certified by the Ministry of Industry and Trade); Implementing plans for efficient and economical energy use; Introducing reward and penalty policies for employees regarding energy-saving and efficient usage practices. Annually, the plant reports its energy usage status and energy-saving plans to the Department of Industry and Trade, and it conducts energy audits every three years as required by law.