Alternative carriers for remote renewable energy sources using existing CNG infrastructure

Optimal locations of renewable energy sources are often remote relative to consumers and electricity grids. In contrast, some existing CNG pipelines pass through optimal renewable energy harvesting regions. The growing interest in the possibility of using geothermal energy in central Australia has created a need to assess the economic, technical, and environmental viability of converting remote renewable energy to fuel for transport using existing CNG pipelines, and to compare this alternative with that required to construct new high-capacity electricity transmission lines. This assessment is reported, using first the conversion of electricity to hydrogen, and then conversion of the hydrogen to methane. The paper also compares the alternative of direct injection of hydrogen into existing CNG pipelines to create “hythane” (HCNG). An economic assessment showed that the relative capital and operating costs are sufficient make the alternative carrier prospect worthy of further consideration.