The outspoken former resources minister, Nationals Senator Matt Canavan, has been talking about one of his favourite obsessions lately: the unstoppable renewables transition and why we should just stick to good old Aussie coal, like we did in the past.

On the conservative side of politics we like to boast about a broad church- a variety of views and personalities. At Coalition for Conservation we often emphasise the conservative value of prudence, particularly when it comes to livelihood, environmental wellbeing, and the wellbeing of our children and future generations.

Unfortunately, there are those among us who hitch their legacies steadfastly to dying arguments, no matter how many rats have deserted the ship.

Canavan insists that coal is cheap, provides jobs and essential grid inertia, or frequency stability to a reliable grid. If this was the 20^th century he’d be correct.

Coal is no longer cheap, when you consider that it’s more than double the price of solar power, which is so cheap that you can get it for a couple of cents per kilowatt-hour. No wonder countries around the world are racing to install it, with more than 75% of new generation in 2019 coming from renewables.

Per unit of energy generated, renewables generates more jobs than fossil fuels. Even in Trump’s fossil-fuel US, the solar industry employs more people than oil, coal and gas combined.

In his recent piece in The Australian (https://www.theaustralian.com.au/commentary/gas-is-not-the-answer-to-our-power-costs/news-story/e5fcbe9d184107fd8e7e4b4022a1fd16) Canavan doubles down on the argument that renewables are the dole bludgers of electricity generation, insisting that renewables work “only part of the time, often unpredictably”.

In scientific terms the name for this “bludge effect” is capacity factor. It is true that solar and wind have capacity factors of only 25-30%. Or that is to say, they work around the same amount as you and I do, before knocking off for a beer.

But a sturdy coal plant can work around the clock, right? Well, no- their capacity factor is around 50-70%, not exactly the 100% that those who worship at the baseload altar like to crow about.

Coal plants also break down. With many moving and hot parts they need scheduled maintenance. Coal quality fluctuates, and their continued operation depends on us desperately looking around for more of the stuff to dig up.

On the other hand, low capacity factors for wind and solar do not translate to low reliability. The sun rises and sets every single day, and in modern times is quite predictable in timing and quantity- in fact you can set your watch to it. A solar panel placed in the sun has no moving parts and will generate reliable power for 25 years or more with little more than an occasional hose down to remove dust. Likewise, the wind often blows in prevailing ways that are surprisingly consistent- ask any sailor.

Australia is blessed not only with a wealth of both resources, but with a wealth of geographic locations, latitudes and weather systems. We have areas of consistent, uncorrelated sunshine (Queensland) and consistent, uncorrelated wind (Tasmania).

Canavan also distinguishes the turbines of gas and coal plants from those of wind generators. He is partially correct in that solar and wind plants provide less frequency stability to the grid than the synchronised rotating masses found in fossil fuel plants. This needs to be offset by the prudent gradual closure of such plants or their replacement with less emission-intensive ones, as proposed by the government.

But an even better idea is big batteries. As their opponents often like to point out, they’re not really that big. They can’t provide backup power for long and are little more useful than a big banana. But this misses the point, because what they are really good at is providing grid stability, and in a more sustainable way than a fossil fuel plant. In the future, we will see truly big batteries.

The key to addressing concerns about renewable reliability is to build enough generation, and to build it in diverse regions, with diverse methods of providing grid stability. We need investing in grid interconnectors between regions, such as the Marinus Link between Tasmania and Victoria, announced as a priority project by Angus Taylor last week.

Indeed, studies have shown that Australia could achieve close to 50% renewables with little more than the right interconnectors, Malcolm Turnbull’s Snowy 2.0 pumped hydro project and a smattering of home batteries.

We are currently around 25%, on track to hit 30% this year. We do need investment in bigger storage, but we have time.

Lately, with lots of sun, wind and expensive coal plants being idled with COVID-related low demand, Australia’s been hitting close to 50% renewables.

The government’s gas plans have been muddled, but given where we are with the penetration of renewables, the availability of storage and the poor state of the planet caused by burning stuff, a (hopefully) short-term gas plan as devised by the government and Chief Scientist Alan Finkel is arguably prudent- and strikes a balance between grid reliability, low cost, and low environmental impact.

Coal on the other hand, does not. And despite having served us well in the past, it never will again. No matter how tightly its straggling idealogues may cling to its soothing and smoky spell.

Dr. Matt Edwards is a director of centre-right environmental organisation Coalition for Conservation (C4C), a research scientist and technology transfer manager at UNSW's School of Photovoltaics and Renewable Energy Engineering, and the founder of BlueVolt, a start-up bringing solar power to cities and the frontlines of the climate crisis, backed by Mirvac and Artesian.