New solar farms in the planning stages will drive capacity even higher. Credit:Rolfo Brenner But quirks are hardly limited to rooftop panels. Optimal outcomes in Australia's energy mix are the exception rather than the norm. The biggest oddity, perhaps, is the attack on renewable energy that is emerging as the favoured weapon of choice of the Turnbull government. Federal Labor was "drunk on left ideology" in pursuing its goal of 50 per cent of renewable energy by 2030, Prime Minister Malcolm Turnbull said last week. Labor-led states with similar goals, including Victoria, were placing stability at risk, he said. Turnbull blamed South Australia's relatively high dependence on wind power for Wednesday evening's outages even though the supply gap was equal to half a gas-fired plant. That plant managed to fire up fully the following day to prevent more outages.

However, the federal coalition's demonising of renewables – complete with Treasurer Scott Morrison brandishing a lump of coal like a grenade in parliament during the week – is not shared by counterparts in NSW. (So-called low emissions coal plants are also viewed as "uninvestable" by the energy sector.) "I want to thank all the NSW electricity generators and their workforces – gas, coal, hydro, wind and solar – for each playing a part to weather the heatwave," Don Harwin, the state's new Energy Minister said late on Friday after emerging from hours monitoring the market at TransGrid, the state's main power transmission operator. "I would also like to thank the 350,000 households with rooftop solar who contributed [on Friday] to our network," he said. At one point, renewable energy was meeting about a quarter of NSW's power demand during the first day of the latest heatwave. NSW's new Liberal Premier Gladys Berejiklian is also understood to be more worried than her predecessor, Mike Baird, was about climate change and the need to prepare for a reduced role for fossil fuels as the state tries to hit its goal of net-zero emissions by 2050. NSW now sources more than 90 per cent of its power from coal and gas plants.

There's another reason for tilting towards wind turbines and solar: it's the only game in town when it comes to investment in new electricity capacity in Australia. New data compiled by the Clean Energy Council show more than 20 large-scale renewable energy projects are already under construction or will start in 2017. That's generating almost 3000 direct jobs and pumping in $5.2 billion in investment. The projects will add 2300 megawatts of additional capacity when complete, the most renewables added to the network since the Snowy Hydro Scheme a half century ago. Much more will be added by 2020 to meet the federal Renewable Energy Target of supplying 33,000 gigawatt-hours per year. "We're seeing unprecedented levels of new investments as the cost of new renewables keep going down," said Kane Thornton, chief executive of the council. "Investors have spoken and are putting their carefully considered investments into wind and solar – they are not investing in coal." NSW and Queensland stand to benefit the most from the new projects currently under way, but South Australia and Victoria will also benefit.

"There's no question that more large-scale solar would have helped in South Australia [on Wednesday], as would more wind power in NSW [on Friday] where the wind resource was quite good," Thornton said. Alan Pears, an energy expert at RMIT University says having more renewables also had the added bonus of bringing more competition to a highly concentrated energy market. "The extra renewable energy on average does damp down wholesale prices by bidding in low and displacing high-cost marginal generators," Mr Pears said. "So its benefit may not be visible at times of extreme peaks or failures, but may still depress average prices over the year." Chris Dunstan, Research Director at the University of Technology Sydney's Institute for Sustainable Futures, said extra renewables would help but the cheapest way to ease the energy crunch would be to give companies incentives to power down during peak periods.

So-called demand side management could, for instance, have avoided the need to cut supplies on Friday to Tomago Aluminium, putting at risk expensive potlines at the nation's biggest smelter. Those with more discretionary needs could have switched off instead. "If we were more methodical about it, we would have a lot more capacity," Dr Dunstan said. CEC's Thornton said falling costs of batteries would make renewables more flexible too. They would also address the matter of rooftop panels pointed north rather than west. Mr Thornton notes, though, that solar panels were far from useless in NSW on Friday, generating as much as 480 MW at 5pm. (Large-scale solar plants can be built to track the sun.) "If ever there was a time battery storage would have played an important role, this week was it," he said.