By Phil Kreveld
There is much detail still to be announced to support the Coalition’s energy plan, announced by shadow energy minister Dan Tehan, but let’s discuss some engineering matters that could guide electricity system policy development.
As for the baseload mentioned by Tehan, this no longer exists—it is due to massive expansion of rooftop solar, aided and abetted by the household battery programs, and the encouragement of new investment in C&I rooftop solar.
The term ‘baseload’ has become meaningless as all large-scale generators connected to the transmission grid—whether hydro, gas, or coal—are not assured of base load—energy varies during the day and night. It is always ‘load following’. It is the reason why coal-fired power stations are going over to two-shift operation, essentially keeping boilers going during the day to keep turbines warm, ready for service during nightfall. Not that they would be the only game in town then, as wind farms are often very effective during the dark hours. To restore baseload, mechanisms for restraining rooftop solar investment, including disablement, and also of home batteries would have to be found.
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If the idea is to retain coal, as stated by Tehan, the suggestion is that it would be an effective alternative to nuclear generation—available sooner, and more cost effective to the taxpayer. Refurbishing Yallourn, Eraring, Loy Yang, Vale Point, etc., will not be undertaken by the owners—government money would be needed. It would most likely be not only quicker but would avoid going through the legislative manoeuvres to achieve the appropriate laws and regulations relating to storage of radioactive waste.
So, as to cater for the grid that the Opposition could inherit if it succeeds in gaining the government benches, Tehan would be well advised to regulate that most coal-fired plant generators should capable of running as synchronous condensers, so that, for example, during daylight operation with maximum concentration of solar power, the steam turbines would be disengaged and the generators would be run as synchronous condensers. Although Tehan wants to redesign the Capacity Investment Scheme, the above suggestion would take away the urgency. In truth, our primary need in the grid now is volt-amps, reactive (Vars) as supplied by syncons rather than watts.
A national focus on climate change notwithstanding, retention of upgraded coal-fired power stations in providing a more stable voltage could actually permit more connection—faster connection even, of grid-following wind and solar. The technical point being that higher available fault level and elevated short-circuit ratios at renewable energy zones through retention of synchronous generators would make grid-following inverters so much easier to connect to the grid—as well, and this would be important to Tehan, allowing more rapid deployment of solar and wind generation. There is, therefore, not an either-or situation. We could be belching a tonne of CO2 per megawatt from coal and half that value from gas, but more rapidly expand clean generation for the growing demand of energy, yet reducing our overall carbon load.
The commentary in the Australian Financial Review and in The Australian, unsurprisingly was devoid of analysis of the Opposition’s proposal. News Corp in particular is no friend of the government. The point being made here is that the commentary, unfortunately, is inevitably slanted—and no electrical engineer valuing their job would have been game to inject some rational commentary at News Corp’s energy summit.
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The effective brake on electrical energy expansion is the lack of cohesion between government policies, jurisdictional independence, the national electricity law, the rule-making body, the investment approval body, and ring-fencing of distribution networks. Therefore, we experience the inability—not through lack of intelligence in the people employed—to analyse the electricity system as one machine.
Neither Tehan nor his counterpart, Energy Minister Chris Bowen, are talking ‘rubbish’—both are stymied by the treacle-like expansion of the grid and generation capacities. The renewable transition is proving itself as not delivering lower cost electricity—but that is not to imply that reducing CO2 emission is not important—it is. However, it is not a matter of ideology.
