By Phil Kreveld
Ausgrid’s application to the Australian Energy Regulator to install 130MWh battery capacity in its Mascot-Botany, and Charmhaven (north coast of NSW) distribution networks has set off vigorous protests by AGL with accusations of anti-competitive behaviour (The Australian, Tuesday 23 September).
Ausgrid’s reasoning is that the proposed battery capacity will allow it to soak up excess household and business rooftop generation in daylight hours, and to provide the energy back to consumers in the hours of darkness. Of course, AGL’s reasoning is easy to grasp because were Clare Savage and her team at the AER to allow the scheme as additions to Ausgrid’s regulated assets, it would negatively impact AGL’s energy sales.
Related article: Stressing over Australia’s 2035 emissions reduction target
AGL’s argument is that distribution networks are monopolies and therefore should not be allowed to generate and sell energy. It conveniently overlooks that AGL’s very size resembles a mighty monopoly, and furthermore that the energy it sends to distribution networks via Transgrid’s high-voltage transmission lines, is utilising a monopoly.
The Ausgrid application brings into sharp focus a reality to which state and commonwealth governments, and regulatory authorities are wilfully blind. Distribution networks of Australia are becoming independent of bulk-generated electricity by virtue of the growth of solar rooftop capacity. The main reason that growing independence is not translated to a commercial reality is twofold (a) technology changes needed at sub-transmission and medium voltage networks, and (b) adherence to the current rule book, i.e., the rule book AGL is relying on in its objections lodged with the AER.
Meanwhile, the Australian Energy Market Operator is gearing up to exercise the Emergency Backstop mechanism to force increased energy demand in distribution networks by turning off rooftop solar, all in the name of maintaining energy flow through the HV grids for voltage stability. The AER rule book is a tough one, every addition to regulated assets requested by distribution network service providers is gone over with gimlet eyes—unsurprisingly since more than 40% of domestic and small business tariffs are network costs.
But let’s get to the wilful blindness. What is really a contiguous system, connecting Mrs Kerfoop’s rooftop solar all the way to AGL, or Origin, or whomever in the big end of town, was broken up decades ago into separate businesses, for which read profit centres. The Australian Energy Market Commission and the AER referred to above were put in charge of making sure the players were behaving themselves.
The result today is that the shareholders rank first, and the Commonwealth Government ameliorates the voter’s pain with rebates on electricity bills and subsidising batteries for private use. At one end, consumers are encouraged to virtually get ‘off grid’ and at the other end, the commercial players run to the regulatory authorities when the profitability of their patch is threatened. Nationally we are chasing our tail, but in ascending cost circles.
We cannot be sure but very likely the scheme sketched below is what Ausgrid is contemplating. It may not be all the way to sub-transmission but it will be for sure in the medium voltage network (the ring main unit to the next transformer downstream), and yes, it would make them a generator of electrical energy—and a much more efficient one with fewer energy losses than bringing the goods from Eraring or New England, etc.
The Battery Energy Storage System is charged by excess rooftop solar energy. For clarity’s sake, the charging of the BESS and the voltage support for rooftop solar are shown as separate functions, but in practice they would be combined in a bi-directional converter. The scheme shown here is in practice far more complicated, however, it provides the overall idea.
Related article: Picking up grid vibrations
Clearly, there is politically no consideration given to the ‘train crash’ in progress—increasingly energy-independent DNSP, and the buildout of more transmission lines and remote energy zones. A reading of AEMO’s Integrated System Plan for 2050 shows a third of energy as self-generated. Is anybody dwelling on this projection?
Ausgrid’s proposal to the AER appears to be an attempt to divert the ‘distribution train’ from oncoming traffic on the high voltage transmission highway. And, yes, when you think about it, why can’t DNSPs be independent self-sustaining networks.
