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100% renewables is easier and cheaper than most people think

Andrew Blakers's picture
Professor of Engineering Australian National university

Andrew Blakers is Professor of Engineering at the Australian National University. He founded the solar PV research group at ANU. In the 1980s and 1990s he was responsible for the design and...

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  • Mar 30, 2021

Australia is the global renewable energy pathfinder. It is demonstrating that reaching high penetration of solar PV and wind is straightforward at low cost.

Australia is installing solar PV & wind at 10 times the global per capita average rate and 4 times faster per capita than the USA, Japan, Europe or China. Australia’s National Electricity Market (NEM) and the state of South Australia currently have PV & wind penetrations of 25% and 70% respectively and are tracking towards 40% and 100% respectively in 2024.The current (2021) and market futures (2024) price for electricity is in the range of US$35/MWh which includes both generation and balancing.

In response to rising PV & wind penetration, grid-balancing investment in Australia is predominantly in Gigawatt-scale off-river pumped hydro, batteries, transmission and demand response. Bio, nuclear, hydrogen, power-to-X etc are miniscule or absent. The USA has 35,000 off-river (closed loop) pumped hydro sites with a vast amount of storage (1.4 million GWh). A global atlas of 616,000 sites is available at and details are at

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

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Matt Chester's picture
Matt Chester on Mar 30, 2021

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 Blakers's picture
Andrew Blakers on Mar 30, 2021


  • Australia is installing solar & wind 4X faster per capita than the USA, which means that critical mass of scale and skill is available everywhere, which leads to low prices.
  • Australia has 13 GW of rooftop solar [equivalent to 170GW in the USA] and is installing at the rate of 3.5GW per year [equivalent to 50GW per year in the USA] which means that most of the population is very aware of solar - more than a quarter of homes have solar on their roof because the resulting electricity is much cheaper than from the grid.
  • Australia has realised that storage is not a problem. Batteries are being deployed in most places. Two pumped hydro systems are under construction (2.3GW, 350GWh) and another dozen are under serious consideration (none include new dams on rivers).
  • A relatively free market with sort-of-adequate interstate interconnection allows the best commercial solutions to flourish, which happens to be solar, wind, pumped hydro and batteries.
Matt Chester's picture
Matt Chester on Mar 30, 2021

Thanks for the follow up, Andrew! The per capita numbers are interesting, for sure, but is there any nuance missing when looking at it just that way as opposed to based on land area, available land area, and in particular the solar irradiance of that land?

Thanks again!

Andrew Blakers's picture
Andrew Blakers on Mar 31, 2021

USA and Australia both have good wind and good sun. Australia has 4000 pumped hydro sites and the USA has 35,000, which are about 200X more than needed to support 100% renewables. The USA needs only 30,000 km2 to get all its electricity from solar & wind.

Peter Farley's picture
Peter Farley on Apr 6, 2021

There are two key differences,

1. Rooftop solar power in Australia is far cheaper than in the US because many (not all) of the regulatory and permitting hurdles have been removed so the installed cost pre subsidies of rooftop solar in Australia is about US$0.8-1c/W and the amortised cost of energy works out at less than US$0.10/kWh. So even though feed in tarriffs are now down to around US 4-6c/kWh and some new customers can't export energy at all due to grid capacity limits, solar installations are still booming.

In addition retailers are required to buy small scale renewable energy certifcates when the system is installed based on expected lifetime output. This reduces the cost of an installation by about 25-30% but is declining every year.

Finally in response to power shortages and high prices  a couple of years ago some states offered grants or low interest loans to increase solar capacity but again these are now being scaled down as reliabilility has improved and wholesale power prices have fallen 60% in the last three years

2. Grid power prices in Australia are expensive, for many reasons one of which is privatisation of mostly state owned utilities which has allowed price gouging by oligopilies so typicaly households pay US 23-35c/kWh

The net result is that homeowners and small to medium businesses have a real economic incentive to install as much solar as they can use

Matt Chester's picture
Matt Chester on Apr 6, 2021

Rooftop solar power in Australia is far cheaper than in the US because many (not all) of the regulatory and permitting hurdles have been removed so the installed cost pre subsidies of rooftop solar in Australia is about US$0.8-1c/W and the amortised cost of energy works out at less than US$0.10/kWh. So even though feed in tarriffs are now down to around US 4-6c/kWh and some new customers can't export energy at all due to grid capacity limits, solar installations are still booming.

This difference is a frustrating fact, but I'll look at it from the optimistic side: that also means it's a difference that can be resolved-- it's not a matter of some inherent geographic or resource difference that can't be equalized, but shows how policy in the U.S. can be changed to alter the outcomes to be more like Australia, seeking to replicate their success.

Thanks for sharing, Peter!

Peter Farley's picture
Peter Farley on Apr 8, 2021

Perhaps you can look at it in an entirely different way. Fossil fuel power generation in the US in the last year was 2,400 TWh from an area of 8 million square km or 300 MWh per square km. Last year Germany with old technology, limited open land and relatively poor wind and solar resources generated 230 TWh or 660 MWh per square km from non hydro renewables.

Now the average wind turbine in Germany generates 4.4 GWh/y. The average new turbine in the US generates about 12 GWh. This will rise to about 20 GWh as 4.5-5.5 MW class machines are adopted. Similarly Germany has about 275 million solar panels which average 185 kWh each at an average 11% capacity factor. The US has better sunlight and a higher share of tracking solar so it can expect an average of around 21% capacity factor on 420W average rating from new panels so it can expect an average 750 kWh+/y from new solar panels.

 In other words new wind and solar in the US can be expected to generate about 4 times as much energy per unit as existing German capacity. So if the US emulated Germany and had one wind turbine per 12 square km and 750 solar panels per square km it could generate 1,900 MWh/square km from wind and solar alone, let alone geothermal, biomass, tidal etc.

That is more than enough energy to eliminate gas and coal from electricity generation, fossil fuels from heating cooking and land transport and provide enough energy to manufacture synthetic fuels for air and sea transport

Bob Meinetz's picture
Bob Meinetz on Mar 30, 2021

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!"

Andrew Blakers's picture
Andrew Blakers on Mar 30, 2021

Those who discern technology and economic trends early have a commercial advantage. Australia offers a "heads-up" for alert US energy professionals.

Solar & wind are now cheaper than new-build fossil fuel generation, which makes all the difference. They comprise three quarters of global net new generation capacity additions. The trend is obvious. 

Australia is deploying 7 GW/year of new solar & wind [equivalent to 90 GW/year in the USA], is building no new fossil fuel generators, and is retiring most coal power plant by 2030. Fossil gas has fallen to just 5% of annual generation in the national electricity market.

Storage in not a problem. Australia has 4 GW (350 GWh) of batteries and pumped hydro under construction [equivalent of 50 GW (4000 GWh) in the USA].

Its obvious to most professionals that Australia is headed to 90%+ renewable electricity during the 2020s (because solar & wind are so cheap), then 200%+ as electrification of land transport & heating proceeds during the 2030s.

Where people live in South Australia (which is also where the solar & wind is being deployed) it is not a windy desert. Many states around Texas are sunny & windy and look like South Australia and could readily follow its example towards 100% solar & wind PROVIDED they interconnect with the rest of country so that they can make money by exporting low cost solar & wind electricity.

Bob Meinetz's picture
Bob Meinetz on Mar 31, 2021

"Solar & wind are now cheaper than new-build fossil fuel generation."

Huh? Solar & wind are new fossil generation. There isn't a single wind or solar farm in the world that doesn't depend on natural gas turbines to smoothe its intermittent, variable generation. No more time to waste on sources that rely on fossil fuels.

"Fossil gas has fallen to just 5% of annual generation in the national electricity market."

Nonsense. Fossil gas generates 21% of Australia's electricity.

If you're going to continue to post propaganda here, be prepared to be called out on it. Climate change - it's more important than anyone's "commercial advantage".

Andrew Blakers's picture
Andrew Blakers on Mar 31, 2021

"Fossil gas has fallen to just 5% of annual generation in the National Electricity Market." The NEM services 75% of Australian demand. In the January-March quarter, the generations shares in the NEM were 5% fossil gas, 66% coal, 29% renewables (mostly solar & wind). By the end of 2021 the solar & wind fraction will be 35%. You can see NEM data in almost real time at

Fossil gas still dominates in remote cities and mining precincts outside the NEM, but is rapidly having its market share eaten by solar & wind.

Legacy fossil gas generators are indeed helpful in a peaking role. However, batteries and pumped hydro are steadily eating this market also.

I think these discussions are well served by respect and politeness.

Joe Deely's picture
Joe Deely on Mar 31, 2021


Thanks for the link on NEM data. Great tool.

Hoping to see a lot more utility scale solar and storage in Australia.

The first 400 MW stage of the New England Solar Farm near Uralla in New South Wales has reached financial close, thanks to debt financing from Bank of China, Commonwealth Bank of Australia, and Westpac. 

The New England Solar Farm will eventually become a 720 MW solar installation combined with a 400 MWh battery energy storage system on site. It is hoped this first stage of the enormous project will be connected to the National Energy Market (NEM) and produce clean solar energy by July 2022. It is tentatively set to be fully operational by the end of 2023.

Of the 400 MWh lithium-ion battery storage facility planned for the site, UPC/AC Renewables plans for the first 50 MWh, which is supported by the New South Wales government’s AUD 75 million ($58.4 million) Emerging Energy Program, to be operational by mid-2022, along with the first stage of solar installation. 

There appears to be about 23GW of coal power plants currently active. Looking forward to seeing them retired - one by one.


Andrew Blakers's picture
Andrew Blakers on Apr 1, 2021

Australia is installing 7GW of new solar & wind per year, so replacing 23GW is not a difficult target, even after accounting for the capacity factor differences. Liddell (2GW) and Yallourn (1.5 GW) are closing in 2023 and 2028 respectively, and it is widely expected that many others will close during the 2020s because of declining electricity prices caused by the flood of new solar & wind.

Xisto Vieira Filho's picture
Xisto Vieira Filho on Apr 5, 2021

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.

Andrew Blakers's picture
Andrew Blakers on Apr 5, 2021

The Australian Energy Market Operator runs the grid and produces reports on current and forecast stability issues:

Connection between Australian states is relatively weak. Much stronger interconnection is important for smoothing out local weather as the PV/wind fraction increases.

South Australia demonstrates that high levels of PV and wind are feasible. The state of South Australia has a population of 1.7 million people. South Australia is currently generating 70% of its electricity from wind and solar (6-month moving average). The balance is generated from fossil gas with a small fraction (~1%) of net imports/exports. South Australia has no hydroelectric, coal, bio or nuclear generation. The power capacity of the connection to the other states is one quarter and one half of peak and average loads respectively. Recently, South Australia derived more than 100% of its electricity load from each of PV alone and wind alone for one hour. Combined, PV and wind regularly exceed 100% of the load for whole calendar days (midnight to midnight) with the excess being exported to other states. PV and wind generated more than 90% and 100% of the total load for 37 and 5 calendar days (24-hour periods) respectively in 2020. PV and wind produced more than 80% of the load for five discrete 7-day periods. This demonstrates an ability to manage high levels of PV and wind over lengthy periods. These landmarks will be quickly surpassed because deployment of PV and wind continues apace.


Peter Farley's picture
Peter Farley on Apr 6, 2021

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

Gary Hilberg's picture
Gary Hilberg on Apr 6, 2021

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.  

Andrew Blakers's picture
Andrew Blakers on Apr 6, 2021

COVID caused entire industries to shut down and a vast change to work and education patterns - all within a few months. A bit more disruption to save the planet for our children is not that hard to cope with.

70% of Australia's emissions are caused by electricity, land transport and heating. Electrification of land transport (via EVs) and heating (via heat pumps and electric furnaces) requires doubling of electricity production to 500 TWh per year. We need to double PV/wind deployment to achieve this by 2040 - which is not at difficult because of their compelling economic advantage over fossil fuels.

10% of emissions are from fugitive methane that vanishes as fossil fuel exports vanish.

The remaining 20% is more difficult - we can deal with that in the 2030s, but lets do the 70% of easy stuff in the 2020s.

Obviously it is important to divert developing countries to PV/wind rather than having them follow down a fossil fuel pathway. That is why Australia is important - it is a global pathfinder to a PV/wind dominated electricity sector.

Peter Farley's picture
Peter Farley on Apr 7, 2021

If we couple energy efficiency measures with electrification, there is not much need for increased electricity generation. For example electrifying all road transport uses about 40 TWh. The entire Australian grid produces about 240TWh so electrified transport is only a 16% increase in demand.

However somewhere between 10 and 15% of energy use in Australia is used in the production, processing and distribution of fossil fuels, so therefore little change in electricity use if we can minimise production and use of fossil fuels.

Further 70% of gas use for heating is used on applications below 150C. All of these can be replaced by heatpumps with a mean COP of 4, but if building upgrades and process efficiency are pursued in parallel with heating upgrades, then heating energy requirements can be at least halved meaning that the 200 PJ of gas used in these applications can be replaced with about 10-15 TWh of electricity.

The Italian economy has three times the industrial concentration of the Australian econmy and its main cities are hotter in summer and colder in winter than Australia so one would expect higher electricity use per capita, but it is around 47% lower. Thus if we were serious about energy efficiency one could hope for at least 2% per year reduction in demand so over 20 years reduction in demand for existing applications could reach 90 TWh. That would more than offset any increase due to electrification of heating and land transport 

Dudley McFadden's picture
Dudley McFadden on Apr 6, 2021

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.

Andrew Blakers's picture
Andrew Blakers on Apr 6, 2021

The USA will have few technical difficulties in reaching high levels of low cost PV/wind electricity. The lowest cost option requires (i) strong interconnection of North America; in winter, solar flows north and wind energy flows south (ii) plenty of pumped hydro and battery storage.

Same deal in Europe: offshore wind in the North Sea, solar in the south.

Importantly, 80% of the global population lives at moderate latitudes where there is low solar seasonality and no cold winters.

Check out our global off-river pumped hydro atlas containing 35,000 sites in the USA:

Gary Hilberg's picture
Gary Hilberg on Apr 7, 2021

Having worked on the development of run of the river hydro facilities in the US for just a few years and watched the development timeline for these resources, it will not happen fast. Also the costs and time to build once permitted is very high, the assets last literally forever - very good, but financial organizations discount forever very quickly.  A couple of success stories in the US - Rye Energy, but not many.  

Also one major issue with all hydro is consumptive water use - lots of evaporation and this needs to be accounted for.  

Andrew Blakers's picture
Andrew Blakers on Apr 7, 2021

Australia has 2.3GW (350GWh) of pumped hydro storage (2 separate projects) under construction (equivalent to 30GW, 400GWh in the USA). There are a dozen other projects under detailed consideration. None (none) involve significant interference with rivers which hugely reduces environmental pushback. Several GW of 1-hour batteries also.

Water and land requirements are trivial (about 3 litres per person per day to support a 100% renewable electricity system). See "A review of pumped hydro energy storage",

In Australia, the PV/wind penetration will reach 30% at the end of 2021. The drivers in the USA for new storage are still small because the PV/wind penetration is small, but will hopefully grow rapidly under Biden.

Take a look at our Global pumped hydro atlas:

Peter Farley's picture
Peter Farley on Apr 8, 2021

You have to remember that with fossil fuels after you account for exploration, extraction, refinement, distribution and eventual burning anywhere between 50 and 95% of the energy is lost. With solar and wind it is around 10-20% losses. As an example a hot water heater powerd from a coal plant after accounting for the energy used in mining transport and processing of coal and 35% thermal efficiency convers about 27% of the energy in the coal into hot water so you need 15.5 kJ of energy /litre/C.   On the other hand if rooftop solar is driving a heatpump hot water system with no transmission losses  and a COP of 4 the solar panels have to deliver around 1 kJ/litre

Energy use per capita in the US is almost double that of southern European countries  which are hotter than most of the US and more industrialised. So in an efficient renewable system, US energy use could be reduced by about 70% without impacting the comfort or mobility of the citizens.

As for energy potential the US currently uses 120 ExaJoules every year. If it was serious about electrification and energy efficiency it can reduce that by 60-80% but using the lower figure i.e  a 60 % reduction total energy use can be reduced to 12,500 TWh/y which works out at around 1,500 MWh/square km. With modern wind and solar and some hydro and bio-waste to energy the US can easily generate between 2,000 and 2,500 MWh/square km. This can be done with the same density of wind and solar that Germany has today. Adding in offshore wind and the remaining nuclear, geothermal, wave and tidal energy. the US could have a superabunndance of energy in an all renewable system. There are issues of storage and transmission to be resolved but that is another question but one which can also be quite easily solved

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