Using gas to generate electricity doesn’t sound very green. That probably explains why there are two very different points of view about the use of gas as a component of the renewable energy transition.
On the one hand, there are those who simply can’t accept that gas should have any part in our energy future and, as a result, simply demonise it. In the other camp are those who insist that gas is a great enabler to help fill in the gaps when intermittent renewables are temporarily falling short of meeting demand.
Let’s start from the premise that, despite what some loud voices say, Australia is on the way to meeting our renewable energy and emissions reduction targets.
However, even the strongest proponents would concede that there is still a way to go with some of the elements, not least storage and distribution infrastructure. Nevertheless, the generation piece is well established and consistently being improved.
One of the few remaining “sticking points” is how to manage gaps in generation, when there is a shortfall between supply and demand.
In other words, even when we get to the point where renewable sources can provide all of our energy needs most of the time, what do we do when it doesn’t?
It’s a reasonable question, and conversation, to have.
We’re seeing less debate about whether a transition to renewable-sourced energy is viable and a general acknowledgment that the time and effort being put into pursuing this ultimate renewable energy future is worthwhile.
However, that doesn’t mean that there aren’t some reasonable questions that should be asked about the transition as it happens and how the eventual “final” setup will work.
Whether we get to the point where more than 100 per cent of our energy needs can be met by renewables or not, in the meantime we need other sources to meet a proportion of demand – and sometimes at relatively short notice.
On a good day for renewables, the shortfall is less than five per cent, but on a bad day, with not much wind and winter levels of sunshine, it could be 10 or even 15 per cent, at least for the next several years before more major renewable projects (including greater storage capacity) come online.
Which leads to the biggest remaining point of contention: how do we create and maintain a reliable source of dependable energy that will definitely be there whenever it’s needed?
If the system has gaps that aren’t filled and becomes unreliable – not to mention if we’re forced to use less appealing stop-gap measures – public support for the entire process could be severely undermined.
Wind is unreliable.
No matter how positive you are about having the wind provide a proportion of our energy mix, it’s clear to everyone that it’s not a consistent contributor.
While the share of wind energy in the National Energy Market (NEM) has averaged 13.1 per cent over the past 12 months, there are stretches where the average has been around 10 per cent and then some weeks, like the second week of April, when the average was down closer to 5 or 6 per cent.
That’s not to diminish the value of wind-generated energy, but simply to acknowledge the reality. If we’re not going to be realistic about something as clear as that, we won’t get where we need to go.
In fact, denying this reality helps open the door for the naysayers, because ignoring facts that are inconvenient to your position is the fastest way to lose credibility or anything resembling the moral high ground.
Pumped hydro is pretty reliable and dispatchable.
In that April week when the wind blew less than it had since being measured as part of the energy generation mix, the amount of sunshine wasn’t terrible. Although the days were a bit shorter than the peak of summer, the sun shone for most of those days.
However, according to David Osmond, an engineer who runs a simulation of the output of wind and solar in the NEM using real-time data, while wind energy delivered only 42 per cent of its annual average, Wind plus Solar was 67 per cent of the annual average. So, even with solar near its average, that combined figure was also a record low.
Osmond points out that because the share of the energy mix provided by wind and solar was consistently bad for the entire week, hydro was able to meet most of the shortfall.
“The worst weeks tend to have two or more shocker days, where hydro falls a long way short of filling the gaps,” he explained.
Since this particular week didn’t have any really bad days, hydro was able to fill most of the gaps, Ormond says. However, other weeks with a couple of those “shocker” days have seen the proportion of the overall energy mix provided by renewables down to 90 per cent.
Which brings us to gas as a gap-filler.
In an ideal world of energy generation, we wouldn’t use any fossil fuels or anything that impacts the environment, either in the generation process or through emissions.
That’s a wonderful target but, once again, we need to be realistic about how we get there. An ideal world isn’t reached purely by being idealistic.
The argument against using gas in the energy mix is that it isn’t 100 per cent clean. However, nobody is claiming that it is.
Is it a feasible option for filling the gaps when renewables aren’t providing all the energy we need? That’s hard to argue against.
Is it a less environmentally impactful option than keeping coal-fired power stations operating for longer, just for when they’re needed? That’s probably not even a sensible question.
Would gas-fired power be operating all the time? Hardly. It would only need to be switched on now and then, when needed to support renewables. The fact that it can be switched on and off and come up to speed virtually instantly is, in fact, its greatest advantage.
Imagine it only being switched on for a few hours a month. If that was the cost to underpin and support renewables, would it be worth it? Maybe.
Many pragmatic supporters of renewables argue that gas might just be the best option for supporting renewables because it literally fills the gap. No more, no less.
They say that a push to ban gas could unintentionally undermine the transition to renewables by making the entire process more susceptible to those days when the wind refuses to blow hard enough at the same time as the sun isn’t shining.
Not to mention that trying to exclude gas from the mix only emboldens opponents of a renewable-driven future who can point to a week where the wind fails to blow as a big part of their case that renewables are not the answer.
As always, we simply ask the questions, listen to the various responses, and try to understand and explain the options. Policymakers will follow their own path and we will keep an eye on how things progress. We hope they’ll strike a fair balance that will result in stable, renewable, and affordable energy for all Australians.