Solar power generation systems can be categorized into two main types: grid-connected (on-grid) systems and standalone off-grid systems. The grid-connected systems can be further divided into two groups: those with power purchase agreements (PPA) and those without. In this report, systems with PPA refer to projects that have contractual agreement with utilities and had already commenced commercial operations. Systems without PPA refer to independent power supply (IPS) producers who generate electricity for self-consumption or to provide electricity directly to other customers.

        In 2023, Thailand cumulative installed solar power generation capacity reached 5,034 MW, representing an increase of 505 MW or 11% from 2022. This capacity includes 3,229.08 MW from grid-connected systems with PPA, showing an increase of 87 MW or 2.77%. Grid-connected systems without PPA accounted for 1,792.01 MW, an increase of 416 MW or 30.19%, while off-grid systems contributed 12.52 MW, a 2 MW or 20.59% increase compared with 2022 (Table 1.3).