Around 6 AM, solar panels on the factory roof of FLAT Vietnam Company at DEEP C Industrial Park begin generating electricity. The system gradually reduces its output between 5 PM and 6 PM, as workers conclude their shifts.

According to a FLAT Vietnam representative, the electricity generation cycle closely aligns with the factory's peak daily consumption. The company views solar power as an integral part of its production chain, rather than merely an energy investment.

On sunny days, the system reaches a peak output of over 9 MW, representing 80-85% of its design capacity, and meeting approximately one-third of the factory's electricity demand. On average, the business saves around VND 100 million daily in electricity costs purchased from the national grid.

FLAT Vietnam is also exploring an additional investment of approximately 1.5 MWp on the remaining roof area.

The rooftop solar power system at FLAT Vietnam. Photo: Quang Hung

FLAT is not alone; many businesses within DEEP C are accelerating investments following the gradual completion of rooftop solar power policies.

Dao Van Thuan, DEEP C Industrial Park Complex Electricity Manager, stated that before 2025, the industrial park operated approximately 5.38 MWp of rooftop solar power. This year alone, businesses are projected to add an extra 6.2 MWp. In just three months, from April to June, the total solar power capacity in the park increased by over 70%.

According to Thuan, businesses increasingly see solar power not only as a solution to reduce electricity bills but also as a way to meet the emission reduction requirements of global supply chains.

This trend extends beyond industrial parks. The Northern Power Corporation (EVNNPC) reported that in the first half of this year, it added approximately 8,500 rooftop solar customers with a total capacity of nearly 395 MW. This significantly exceeded its plans for both customer numbers and capacity. By the end of June, EVNNPC had over 10,000 customers with a total capacity exceeding 718 MW.

While solar power was previously limited to large enterprises, the model has now expanded to households, schools, medical facilities, and government offices.

Hai Phong, a leading northern locality in rooftop solar development, had 967 customers installed with a total capacity of approximately 60 MW by the end of June. The local power company aims to increase this to 1,200 customers with a total capacity of 110 MW this year.

In Quang Ninh, many localities are also actively promoting this model. In the Hai Ha area, approximately 139 customers have installed rooftop solar power with a total capacity of about 1.6 MW. A representative from Hai Ha Power Company said they have collaborated with local authorities to survey the needs of individual households, schools, and medical centers, rather than applying a universal model. Investment scale is calculated based on roof area, electricity consumption needs, and the power system's capacity to receive it.

They estimate that for households consuming about 800-1,200 kWh per month, the payback period is approximately 5-5.5 years. Households with high daytime electricity consumption can recover their investment faster.

In Mong Cai, the power sector is collaborating with the Provincial People's Committee to install solar power on the roofs of schools, medical stations, and public administrative offices. According to the plan, registered schools must complete installation before 30/8 to be ready for use before the new academic year.

EVNNPC attributes the market's rapid growth to several factors. The legal framework for self-produced, self-consumed rooftop solar power has become clearer following the issuance of Decree 58/2025 and the Prime Minister's directives on electricity saving and solar power development. Concurrently, equipment costs have decreased, technology has improved, and awareness among businesses and residents regarding the benefits of solar power has increased.

Another significant change is the increased active participation of local authorities. According to EVNNPC, all provinces and cities under its management have plans or directives for rooftop solar power development. Among these, 15 localities have set specific targets for public offices and households. Many areas have assigned targets down to individual communes, wards, or specific groups of schools and medical facilities.

Some localities are also exploring support mechanisms such as green credit, incentives, simplified investment procedures, or expedited processing of applications. In Nghe An, the Provincial Environmental Protection Fund offers loans with a preferential annual interest rate of 1.5% for environmental projects, including clean energy initiatives.

Despite its rapid development, rooftop solar power cannot completely replace the national grid. Its generation output depends on weather conditions and primarily meets daytime demand. At night or on less sunny days, the national power system still bears the majority of consumption needs.

Therefore, experts suggest that accurately calculating the investment scale and electricity consumption needs for each customer is crucial for economic efficiency. Furthermore, expanding this model requires simplifying procedures related to construction, fire prevention, and fire fighting, as well as addressing challenges in power system operation.