Mr. Vu Van Diep's family (50 years old, Tinh Gia ward, Thanh Hoa province) is one of the households choosing to invest in a large-capacity rooftop solar power system combined with storage batteries. In his house, all equipment is used entirely by electricity, from air conditioners, induction cookers to other household appliances, so the summer electricity bill is very large, sometimes up to more than 4 million VND per month.
At the beginning of 2025, after a period of research, Mr. Diep's family invested nearly 100 million VND to install a solar power system of about 7kW, combined with a 10kWh storage battery. Initially, the family installed 10 solar panels with a capacity of about 6kW, then installed 2 more when renovating the roof. On sunny days, the system generates about 33kWh of electricity/day, the battery is fully stored from about 10h. Solar power is used directly during the day, and the remaining part is used in the evening. Thanks to that, the family's electricity bill has decreased from more than 4 million VND to about 800,000 - 1.2 million VND/month. The average savings are currently about more than 3 million VND/month, especially noticeable during peak hot sunny months.
From practical use, I believe that initial investment costs are still the biggest barrier for many households wanting to access rooftop solar power. If there are more preferential loan packages or partial investment cost support, people will boldly install more" - Mr. Diep proposed.
Dr. Nguyen Xuan Quang - Institute of Energy Technology (Hanoi University of Science and Technology) assessed that rooftop solar power and solar-powered equipment are gradually becoming the choice of many households to reduce the pressure of household electricity costs, towards the trend of using green, economical and more sustainable energy.
Dr. Nguyen Xuan Quang said that in recent years, many households have boldly invested in rooftop solar power systems with costs of up to hundreds of millions of VND. However, for rooftop solar power to develop more sustainably in the coming period, the most important thing is not only technology but also mechanisms and policies. According to him, first of all, it is necessary to create a more favorable environment for people to install solar power easily, from connection procedures, technical standards to regulations related to the use of excess electricity. If policies are still unstable or change continuously, people will find it very difficult to boldly invest in the long term. "What people need most is policy stability. When they spend a large amount of investment on solar power, they need to see the potential for long-term exploitation and clear economic efficiency" - Dr. Nguyen Xuan Quang said.
