IN DEPTH: Islands of electricity

By Phil Kreveld, Power Parameters

“No Man is an Island”, wrote John Donne in 1624 making the point that even the loss of one small part, diminishes the whole and that to stand as one, enhances all that makes up the whole. We do well to keep his words in mind—in national affairs, in politics—and yes, also in infrastructure, and in particular when reviewing Australia’s electricity system. A definition of the word system is ‘a collection of elements or components that are organized for a common purpose’. The national electricity market (NEM) idea as conceived by Professor Fred Hilmer in 1994 answers to the definition as does the NEM of today. However, the intervening years between its actual inception in 1998 and today have seen a splintering in asset ownerships, in politisation and government-initiated creation of policy, regulatory and supervisory bodies, each with its own agenda, to a point where the system is fraying, exacerbated by the ‘greening’ politics of various state jurisdictions.

That islands of electricity are close to being created is evidenced by the experiences of solar farms in the West Murray region operating at 50% output because of constraints in remote area zone links connecting to the national grid. It is not the only example of connection problems, and quite apart from major solar generation projects not working to capacity, there is a steady growth in domestic, industrial and commercial solar that are more or less ‘integrated’ in networks but subject to all manner of grid codes and giving rise to stability constraints being put to the test. As one experienced ex-executive from the electricity industry put it ‘everyone wants to do their own thing’ when it comes to controlling their part of the system. There has been separation of state grids from the NEM grid because of frequency instability, creating large islands.

The lack of an overall supervisory and control system governing the NEM from edge of grid all the way to generators, makes ‘islanding’ an inherent probability. Discussion with engineers reveal that there is a strong preference for local solutions, a major concern being control of voltage regulation in distribution networks. Compiling individual network monitoring and control systems into one national, comprehensive one is not theoretically impossible, but in practice, highly unlikely to be achieved in any practical time frame. More likely, as the penetration of renewable resources continues its inexorable rise, the NEM would muddle through under the baleful stare of Governments, charged with ‘keeping the lights on’. Therefore, the time for leadership in initiating a NEM monitoring and control system encompassing the individual distribution networks has arrived. What might that look like in practice, given the diversity in financial and physical structures of networks? It will preferably be Australian technology, and will allow for integration of monitoring and control practices of individual networks. Using an already established monitoring system as the basis for adaption to an Australian version has advantages. There are, however, few examples. One is in use by the South African Electricity Authority, ESKOM. It is a Big Data system covering thousands of network nodes. Trialling such a system already provided with secure encryption and utilising metallic servers to assure Australian autonomy makes sense and still leaves a very considerable amount of engineering to be achieved, the major items being the control protocols, which, as already stated, will differ in distribution networks.

The time required to achieve a NEM comprehensive supervisory and control system will be some years, necessitating adaptability to equipment from major suppliers of monitoring, reclosers, RMUs, transformers, SVCs, etc. The initiative should therefore come from the Australian Energy Market Operator (AEMO), which as an alternative policy could initiate a home-grown system in its entirety. However, starting with an established system, e.g. ESKOM’s and using it as a crystallisation seed for Australian technologies develop around, provides a faster and practicable track. The initiative as suggested here, might also result in a unique market position for Australia in network integration of very large renewable source penetrations.