Analogy:

a

: a comparison of two otherwise unlike things based on resemblance of a particular aspect

b

: resemblance in some particulars between things otherwise unlike

Extension cord: an electrical conductor used to move electricity from where it is available to where it is needed.

The electric transmission and distribution grid is analogous to numerous extension cords arranged is series-parallel configurations, moving electricity from generating facilities progressively toward electric loads.

In its most basic configuration, the grid moves electricity from a powerplant through a series of conductors (extension cords) and transformers to numerous customers at various voltages. Traditionally, individual electric utilities operated multiple generators supplying customers in a single state. These utilities frequently interconnected with other instate utilities to facilitate responses to unusual demands or generator outages. Later, these utilities also connected with utilities in adjacent states for the same reasons.

The advent of Regional Transmission Organizations (RTOs) and Independent System Operators (ISOs) led to multiple utilities in individual states (CA, NY & TX) or in multiple adjacent states interconnecting their systems to enhance flexibility and reliability. These systems relied on more numerous and longer “extension cords”.

Federal and state government interest in expanding the roles of intermittent renewable generation led to the implementation of multiple longer “extension cords” to connect frequently remotely located renewable generation sites to the existing utility grids. In some cases (NJ), participation in an ISO (PJM) led to elimination of some instate fossil generation resources and reliance on electricity imported from other participants in the ISO. In other cases (CAISO & NYISO & ISONE), the ISOs suspended operation of existing conventional generation facilities and contracted with utilities in adjacent states or countries for imported electricity.

The focus on renewable generation has also led to instances in which renewable generation is installed in a preferrable location in one state and connected by dedicated “extension cords” to utilities in other states. These projects have met with significant resistance in the states in which the renewable facilities would be located and in the states through which the renewable electricity would be transmitted but not consumed.

The United Kingdom has shut down much of its conventional generation capacity and makes use of “extension cords” from Norway, Denmark, France, Belgium, the Netherlands and Ireland to supplement and support its growing wind and solar generation fleets. The EU has established legal goals to assure that its member nations are sufficiently interconnected and able to share 15% of their generating capacity by 2030

The most ambitious “extension cord” currently under construction is the Australia Asia Powerlink, which would connect a massive solar collection system and battery storage facility in Australia’s Northern Territory to Darwin and then to Singapore. This approximately 3,000 mile long “extension cord” would deliver approximately 5 GW of battery-supported reliable power. The UK and Morocco had proposed a similar project to transmit approximately 3.6 GW of battery-supported reliable combined solar and wind power from Morocco to the UK, but that project has now been abandoned.

These inter-utility, interstate and international “extension cords” present interesting legal and geopolitical issues and technical dependencies. They have been acceptable as long as all parties benefit. However, that is not proving to be the case universally.