Once solar anxieties are addressed and market barriers removed, Southeast Asia faces an unlimited opportunity for cheap, clean and reliable solar energy balanced using off-river pumped hydro energy storage systems. . Across Southeast Asia, energy demand has risen by about 3 per cent a year in the last two decades. While this can be attributed to growing economies in the region, macroeconomic uncertainty has also led to energy security vulnerability – or the potential lack of natural resources for energy. . The increasing affordability of solar, combined with the rapidly growing population, energy consumption and emissions in the sunbelt region place Southeast Asia on the cusp of a significant energy transformation led by solar photovoltaic technology. However, its development is slow due to a lack of awareness and funds. Many financial institutions are willing to invest in renewable energy. . Furthermore, this novel solar irradiance data set can be used to support solar energy market expansion and inform prospecting, target setting, renewable energy auctions, and other high impact decisions ranging from the micro to the macro scale to accelerate renewable energy deployment throughout. . Sunny Southeast Asia has made great strides in solar energy in recent years, with ASEAN countries now having more than 20GW of solar farm capacity. Despite rapid growth and ambitious renewable energy targets, countries in the region face challenges including supply chain disruptions, political. .