The integration and transition to a DC based community: A case study of the Smart Community in Chiang Mai World Green City

The Smart Community is a real living model community in the mountainous area that completely uses electricity from PV and distributes with DC microgrid in the range of 260 - 297 VDC. The Smart Community is located at the Chiang Mai World Green City of the Asian Development Institute for Community Economy and Technology (adiCET) in Mae Rim Campus of Chiang Mai Rajabhat University, Thailand. The community is comprised of 6 small houses, an office, a minimart, a coffee shop, a restaurant and an organic farm. All of the devices and appliances in the houses and farm are able to operate on DC microgrid, which include lighting, air conditioner, television, refrigerator, computer, water heater, and water pump. These appliances were modified to be able to use with DC as well as AC systems to increase the flexibility of power usage for the transition toward the DC based community. For the other buildings, both AC and DC grids are integrated in the office, minimart, coffee shop, and restaurant. For example during normal operation of the office, the air condition and lightings used the DC grids, but the copier machine and printers used the AC grid. The adiCET faculties, students, researchers and administrative staff used the Smart Community as the working and living place. Operation of the DC and AC usage as well as the issues occurred from the 4-years development were monitored and recorded.