31 The Feasibility of the SWER System in New Zealand as a Low Bit Rate Communications Channel Available to Purchase

New Zealand’s existing low-cost 11kV SWER (single-wire earth return) systems delivers power to remote and rural areas. The residents in these areas have a need for communication channels and many are outside the GSM network provided by competing Telco’s. To avoid expanding the existing copper wire network or utilising existing radio spectrum for communications, the notion of using the existing SWER network as a low bit rate communications is explored. A hypothetical section of SWER network using realistic transformer and transmission line parameters serving rural New Zealand was modelled and analysed, and a pseudo-communications signal injected into the network. It was found that the SWER network may possess the bandwidth capabilities to transmit a low voltage low frequency pseudo-communications signal over many kilometres through both transmission lines and transformers, and may successfully be filtered from the mains voltage at each rural residence/dwelling in the model.