Thursday January 29, 2009, was a big money day for Victoria’s brown coal generators.
After a night of uncomfortably warm temperatures, and a dawn reading of 32°C, Victoria’s residents turned to their air-con and pedestal fans in near record numbers. By 9am, demand had spiked so high that electricity prices had soared to $10,000 a megawatt hour as utilities switched on every last generator they could find to meet demand. These wholesale prices are normally between $35-$50/MWh.
During that day, which reached a peak of 44.3°C in Melbourne in mid afternoon, the wholesale electricity price never fell below $1,000/MWh. For nearly four hours, it hovered around the $10,000/MWh price. The way the National Electricity Market works means that every generator switched on at that time receives that price, even though it still only cost the brown coal generators around $4/MWh to shovel the coal into their power plants. Over an eight-hour period, the state’s generators would have pocketed an estimated $550 million in revenue, near one fifth of their total revenue for the year.
It was, needless to say, an absolute jackpot for the generators. But while this was an extreme case, it was not an atypical event in the NEM. It is estimated that, on average, around one quarter of the revenue from electricity sales each year is generated from the prices gleaned from around 24-36 hours of peak production. The business models of the energy utilities depend on it. But now those models are under threat.
What, for instance, would have happened that day to electricity prices had there been large amounts of solar deployed along the eastern seaboard available to meet demand? ...