Rooftop PV with Batteries for Improving Self-consumption in Vietnam: A Cost–Benefit Analysis

Vietnam's energy sector has become one of Southeast Asia’s most vibrant in recent times. Since the adoption of feed-in-tariffs (FiTs) in 2017, the national electricity system’s installed capacity rose from 47GW to 78GW in 2021, 68% of which are contributed by variable renewable energy growth. Market design and transmission capacity deficiencies complicated extending or reforming FiTs for wind and solar after 2020. Vietnam must expand the use of renewables to achieve net zero emissions by 2050 while meeting growing economic demand, necessitating initiatives including energy storage. This study examines the costs and benefits of rooftop solar plus battery in a sample factory in Ha Tinh province, using roughly 115 MWh of grid-connected electricity annually in manufacturing building materials, and installing 137 kWp solar with battery to be self-sufficient. Calculated by PVsyst as a stand-alone system, based on the current policy scheme and the average battery cost, the company can hardly recover its investment. Therefore, the study considers other assumptions such as subsidies, electricity sales together with social and intangible impacts of corporate social responsibility, improved branding, potential CO2 credit trading, and reduced curtailment risk. It concludes with policy recommendations towards sustainable development target for Vietnam.