100% renewables is easier and cheaper than most people think

The USA looks a lot like Australia (except 13X bigger population) and could readily follow the Australian path - indeed it is likely to do so, driven by similar market forces.

This, of course, begs the question: why the difference? Is it the political/regulatory landscape in the U.S. that isn't set up to succeed in the same way the Australian counterpart is? Or is there simply less of a push to make successes out of these types of initiatives? 

Andrew, your post follows a traditional path once known in marketing as bait-and-switch, but recently assigned the more savory term disappointment management:

"100% renewables is easier and cheaper than most people think."

"Wow," thinks Reader. "I didn't know any country, state, or town in the world was powered by 100% renewables! I must read more."

"[Australia] is demonstrating that reaching high penetration of solar PV and wind is straightforward at low cost."

"Hmm," thinks Reader. "So now '100%' has become 'high penetration'. Let's see where we end up here."

"Australia’s National Electricity Market (NEM) and the state of South Australia currently have PV & wind penetrations of 25% and 70% respectively..."

Reader is now skeptical. "Well, of course SA has high wind and solar penetration. If only we all lived in a windy desert - only 14% of Australians do. The rest of the country remains addicted to fossil fuels."

"..and are tracking towards 40% and 100% respectively in 2024."

"Tracking, shmacking", thinks Reader, in disgust. "Heard it all before."

"The Australian experience is highly replicable since it relies exclusively on cheap, mature technologies from vast production runs that utilize vastly available resources."

Reader has heard this before, too, thinking "I have no use for adjectives, adverbs, or opinions. This is climate change, dammit...give me numbers, or STFU."

But Reader realizes he has had enough. All he can take away is that 25% has been represented as 100% - a lie. He imagines a new slogan for the most hyped technology in human history:

"Solar PV and Wind - Disappointing Since 1955!"

Thank you very much for your information, Andrew. Could you be kind to give some references on how those pumped storage hydros, batteries, transmission interconnections ( interconnecting which subsystems ?) and demand response face problems like: transient stability, dynamic stability, voltage stability, controllable reserves for system operation and resilience (meaning system quick recovery ) ?

Thanks a lot.

In many ways it is even easier than you suggest if a system wide approach is taken to decarbonisation. The simplest route to high penetration renewables is excess generation, energy efficiency and flexible demand.

For example, the worst renewable day in Australia in the last 18 months was 17% of supply when the rolling average was about 25%. On that day hydro ran at about 24% CF for the day. Now to reach 100% renewables over the year the Australian East Coast market (NEM) needs to quadruple solar and wind generation. On the worst day wind and solar would still supply 35%. Already on good wind and solar days, wind and solar alone are supplying 33% of generation, if that is quadrupled, then hydro will be virtually switched off on those days. That in turn means that on bad wind and solar days hydro can run a lot harder without exceeding annual limits, thus existing hydro could provide at least 17% and possibly as high as 27% of demand (at 75% average capacity). That means alternative backup sources such as new pumped hydro, batteries etc would have only needed to provide 30-35% of capacity for the day.

Just as the old system could produce 50% more energy per year than the NEM ever used, if wind and solar capacity were increased by a factor of eight so total renewables could produce 150% of annual demand, that would mean that on that very bad day, wind and solar would produce 68% of demand and hydro 27% leaving only 5% to come from new backup.

But no matter how cheap wholesale power prices become, the incentive for rooftop solar and energy efficiency will remain. Rooftop solar can be generated for less than the price of transmission, distribution and retail costs so Australian consumers and businesses will continue installing behind the meter solar. Australia has the potential for at least 200 GW of behind the meter generation. Even if 25% is curtailed that would supply 75% of current electrical demand.

If Australia gets as energy efficient as Italy or the UK, electricity demand per $ of GDP will fall 40%. So if local storage/flexible demand were cheap enough, Australia could all but eliminate large scale generation   

Just a couple of examples of flexible demand.

1. A simple 300 litre water tank heater heated to about 85-90C and fitted with a mixing valve can store 3-4 days hot water for a family of 4. That means that even in five day period where solar is only supplying 25% of expected input to the hotwater system there is still enough hot water provided by solar PV. Such a system means that night time demand would fall by about 10% across the grid as offpeak loads are transferred from night-time coal to daytime solar

2. Most private vehicles are parked 90-95% of the time. If 25% of that time they were plugged in, drawing between 0-2 kW, an electrified fleet forms a flexible load of 0-44 GW easily absorbing excess wind and solar. If 10% of vehicles had V2G capacity of only 6 kW, that is a peak demand cushion of more than 13 GW, 33% of peak demand

Andrew - focusing on retail and commercial misses the point on high value base load electricity demands and also the direct use of fossil fuels for industrial production.  All of Australian high value LNG segment is driven by fossil fuels and on-site power does not come from the grid. The minerals mining and processing is also mainly "inside the fence".  We need to be honest in our claims, 100% is far from easy, and far from cheap.  Australia being 100% carbon free is irrelevant if Indonesia a country with 10X the population of Australia is 10% renewables.  With carbon the target is total worldwide emissions and reducing the carbon emissions of the first 50% is always much cheaper than the last 5-10%.  IF OECD countries are serious about climate change they need to be honest with their residents, and admit that solving this problem is not being the best dressed guest on the Titanic.  

It seems difficult to visualize how zero-carbon could work out in many industrialized areas of the world.  I am pleased to hear about Australia's success and wish for more.

I am not sure how hundreds of millions of people in the USA and other nations in the higher latitudes could follow the Australian model.  For weeks on end, the outside temperature rarely exceeds 0°C and these cities would be uninhabitable wastelands but for artificial heat.  Heat from vast banks of lithium-ion batteries charged during the summer I suppose?  Multistory apartment buildings lack the roof space for sufficient photovoltaics to heat and light all their tenants.  Tens of thousands of apartment buildings, the only housing option for growing numbers of increasingly squeezed middle class, will never be outfitted with unsightly wind turbines, and neither they nor single-family home residents have the will or ability to clamber to their rooftops to clear snow.  I do see a new career option for chimney sweeps.  Anyhow, insolation is low and confined to a handful of hours of the the brief winter season daylight outside of the sun belt.

People worldwide consume tonnes of plastic, from petroleum, I guess in the future, via solar-powered oil refineries?  How will steel be made, mines operated, and chemicals and forest products manufactured?

I share Mr. Blaker's welcome enthusiasm, very much so, but am struggling with the optimism.