Island Power System Operation with Single-Wire Earth Return (SWER), Solar PV and Diesel Generation –Marinduque, Philippines case study

Abstract

Single-wire earth return system (SWER) is a cost-effective solution to rural electrification. SWER systems operate by drawing power from the grid to supply the end load. With the increasing solar PV system penetration in the consumer side with a back-up diesel generator the concept ofbi-directional operation of SWER system during surplus generation at the load side need to be understood Initial modelling and theoretical network assessment showed that the system could operate if SWER were supported from both ends.A realistic 2 MW capacity case-study using rooftop solar PV was identified for Marinduque, Philippines. Using a sample household demand of serving 1600 households with a 1.34-kWp rooftop solar PV capacity in order to offset a 2MW-capacity from the grid has been undertaken. This has been extended to further analyze energizing five out of the remaining 20 unenergized sitios in the province of Marinduque using SWER system. The additional 2MW capacity and the designed SWER system were modelled to be integrated with the existing power system of Marinduque, Philippines. The designed SWER system and the integration to the existing power system of the province was modelled in DIgSILENT using the power systems data given by the Technical Services Department of Marinduque Electric Cooperative (MARELCO).