In the summer, the HVAC system in commercial buildings imposes heavy cooling load on the national power grid, causing power shortages. It is not uncommon that the power reserves can drop to a record low of 1.64 %, such as during the summer of 2017 due to the extremely hot summer in Taiwan. Instead of relying on constructing new power plants, the Demand Response (DR) Strategy which can curb the instantaneous power demand during the on-peak hours , especially by unloading the building HVAC systems, presents an effective and efficient solution to this problem. In this paper, a large-scale Wide-Area Building Energy Management System , or WABEMS, has been established to integrate various jobsites, which were several hundred kilometers apart from each other, to perform DR strategy together, for a full-scale experimental investigation. The experimental results from several general hospitals and university campuses, indicated that very significant power demand reduction, ranging from 16 % to 25 % reduction from their peaks, has been obtained and validated experimentally and has been analyzed in detail in this paper. More jobsites selected from the BEEUP program sponsored by the ABRI has been integrated into this DR phase 2 program. And the WABEMS platform established in this study has been upgraded into a Simulation and Technology Exchange Center, which warrants a full-fledged DR application platform, providing a vivid solution leading to the Virtual Power Plant concept in Taiwan.