As the anti-renewables crowd continually reminds us, this requires much ingenuity, effort and expense to ensure a reliable supply of power across the national electricity grid, despite the ups and downs of demand and the vagaries of wind and sun.

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But it also involves a lot of investment in changing the transmission grid from one that largely moved high-voltage electricity from a handful of big power stations in the country to the big cities, to one that joins up a multitude of small commercial and household sources of solar and wind power. An increasing proportion of homes will be putting power into the grid sometimes and taking it out other times.

The Morrison government is insisting on a large and continuing role for natural gas in the electricity system. Wood is far from convinced. “The large-scale use of gas as a ‘transition fuel’ – supplying ‘base-load power’ with lower emissions than coal – does not stack up economically or environmentally,” he says.

Nearly 80 per cent of Australia’s hugely increased gas production is exported as liquefied natural gas. It’s sold at the world price, meaning “the good old days of low-priced east-coast gas are gone, making gas an increasingly expensive energy source”.

At present, gas provides about a quarter of Australia’s local energy consumption and contributes close to 20 per cent of our emissions. And whereas electricity prices have been falling, gas prices have been rising.

Gas has been declining as a share of Australia’s power supply since 2014, and this is likely to continue. “Gas will play an important backstop role in power generation when the sun isn’t shining and the wind isn’t blowing – but this role will not require large volumes of gas.”

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In the home, people value being able to choose between gas and electricity for cooking and heating, but this can’t continue. They’ll save money and reduce emissions when all new houses are all-electric.

“The uncomfortable truth is that natural gas is most likely in decline in Australia, and achieving the net-zero target requires that to happen … Attempts to hold back the tide through direct market interventions, such as contemplated in [Morrison’s] National Gas Infrastructure Plan, will probably require ongoing subsidies at great expense to taxpayers.”

As for cars and other light vehicles, achieving net zero by 2050 requires all new cars to be electric or hydrogen-powered by 2035. That’s because, on average, our cars stay on the road for more than 15 years. The alternative is “costly and inefficient measures to scrap large numbers of cars in the 2030s and ’40s.”

To achieve the 2035 target, we need to do what almost every other rich country does. We need to do what the car manufacturers have asked for: set mandatory emissions standards. But neither major party is willing.

Ross Gittins is the economics editor.

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