Idiots Insisting “Over 20% Renewables Is Impossible” Go Into Hiding. Won’t Be Missed.

20 per cent renewable energy

A few years ago it was common to hear “Grids Can’t Handle More Than 20% Renewables”. South Australia (among others) would beg to differ.

I was talking to Finn on Sunday — electronically because computer viruses are less of a threat than biological ones these days — and I mentioned South Australia was producing much more electricity from renewables than it was consuming and that the surplus was being exported to Victoria.  There’s nothing unusual about this, especially on weekends, but it prompted Finn to ask…

“Where have all the 20 percenters gone?  All the people who used to say the grid couldn’t handle more than 20% renewables without disaster?”

That’s a good question, because they used to be all over the place only a couple of years ago. I know they were still around in 2018 when solar energy and wind power began providing 50% of the state’s generation, but it’s almost as if the following…

  • Continued expansion of renewable energy capacity
  • Countries like Spain and Denmark producing over 40% of generation from intermittent renewables1
  • South Australia becoming a net exporter of electricity
  • South Australia being on track to generate electricity from renewable energy equal to 100% or more of its own consumption by 2030 and the Australian Energy Market Operator (AEMO) being down with that

…caused them to disappear.  Where did they go?  Did they suddenly become embarrassed and shut up?  Or were they wiped out by a wind farm on the rampage, determined to prevent them interfering with their evil plan to blow the world out of orbit?

Tilting at wind turbines

Image: XKCD (Full illustration here.)

I’d like to think we no longer hear from 20 percenters as they realized the evidence against them was overwhelming and the shame this revelation brought upon them made them swear to forevermore ensure the facts were on their side before tilting against wind turbines, but I doubt that’s what happened.2

Looking Up Old Scoundrels Is Kind Of Sad

At first my plan was to look up some prominent3 20 percenters, dust off some of their old quotes on the topic, and mock them mercilessly.

But I soon discovered that rather than being fun this was simply depressing.  Being reminded our politicians can so easily ignore a grave danger and put our lives at risk isn’t really what we need right now.  Even when it comes to retired politicians who are limited in the amount of damage they can cause, it’s probably still better for national morale at the moment to pretend they were merely confused when they were being paid money to safeguard our lives and it was only in old age that their brains become fully “fossilized”.

In addition to politicians there were various media outrage merchants who appear to enjoy notoriety and I didn’t see the point in playing their game by giving them more.  You know the type.  The ones currently complaining that everyone’s panicking over Coronavirus except them and by extension their audience, when — apart from the odd punch up over toilet paper — the country’s reaction has been, if anything, a little too blasé.  If we’d gone into this situation sphincters clenched we’d be in a better position than we are today.

Finally, there are people who should have known better, but decided that their gut feelings, that may serve them well in their specialized fields, have exactly the same validity when applied to areas outside their expertise, such as energy4.  These are people with technical backgrounds who often were hands-on involved in building the scientific and engineering marvels our modern lives rely on.  They put people on the moon, sent robots to Mars, and oversaw a computer revolution that put the sum of human knowledge at our fingertips.  Then, towards the end of the 20th century, they looked at the marvels they had helped create and said, “Yep.  This is best we can do.  It’s impossible to improve on this any further, especially when it comes to electricity.  It’s all fossil fuels or nuclear from here on in.”

Engineers don’t get a free pass on this, but they do get a shoulder shrug and an eye roll simply because, soon after they invented the internet, it became clear a small but vocal minority had no problem loudly proclaiming their opinions on a wide range of topics despite being so far out of their depth they’d need mile long legs to keep their nipples dry5.

Some of these people were experts on energy but managed to get it wrong anyway.  Only 13 years ago a respected energy expert from the University of NSW was writing that renewable energy couldn’t power an industrial economy or provide the world with a developed nation standard of living.  This never made sense to me back then and it definitely makes no sense now6 we have entire Australian states moving towards 100% renewable electricity at the same time the developing country of India is building giant solar farms and energy storage facilities, and has abandoned the construction of a considerable number of coal power stations because they’re simply not cost effective.

20% Renewables Was Never A Hard Limit

Around 14 to 20 years ago there were a lot of studies done on intermittent renewable energy and how much grids could handle.  This UK review looked at over 200 and most of them considered penetrations of up to 20%.  There are two main reasons why this 20% figure was chosen.  Firstly, they had good reasons to think it would be okay, and secondly, there were next to no countries getting more than a few percent of their electricity from intermittent renewables at the time.  The question people wanted answered was not…

“Hey, I’ve got 20% solar and wind penetration, is it okay to take that up to 40%?”

It was…

“I’ve got next to no solar and wind generation.  Is it okay to increase it to 15% or 20%?”

The large majority of studies said around 20% should be fine but there may be issues with more than that.  They generally didn’t look at more than that because it wasn’t really an issue at the time.  But the 20 percenters took the large number of papers saying there could be problems at over 20% as evidence that 20% couldn’t be exceeded.  They took an absence of evidence of what would happen beyond 20% as evidence of the absence of ability to go beyond 20%.7  While we all mistakes at times, the fact that many of them refused to re-evaluate their opinion years after several grids left the 20% figure far behind indicated they weren’t making a mistake, they were ignoring reality on bloody purpose.

So 20% was never at any point an agreed upon hard limit.  It was simply useful for grids with next to no solar power or wind capacity at the time to know they could probably get to that point without any major problems.  It was never a line drawn in the sand that couldn’t be crossed without disaster occurring.

South Australia expanded its renewable energy capacity beyond 20% and no hard limits were met.  The two largest changes made were both for the good.  These were the closures of the state’s two coal power stations.  As the most polluting and dangerous form of generation it was good for the health of South Australians and good for everyone in the world who’s dependent on a stable climate for safety and/or food.

South Australia, Denmark, Spain, Etc. Don’t Count

You may be wondering how the hell there could still be 20 percenters around in 2018 when South Australia reached 50% intermittent renewables and Spain and Denmark were at 40% or more?  Their answer was that these places apparently didn’t count because they were connected to other grids.  According to the 20 percenters, the only reason a small region of just 47 million Spaniards was able to make use of more than 20% renewable energy was because Europe’s grid as a whole was less than 20%.

This explanation was ridiculous.  The first reason is because Spain is poorly connected to the rest of Europe,8 and the second is because these places are all capable of operating as separate grids without disaster, despite having more than twice the wind and solar energy generation the 20 percenters insisted was possible.

South Australia has spent a lot of time either fully islanded or mostly islanded, as interconnectors with Victoria have undergone repairs or maintenance.  Disaster did not occur despite the state being at two and a half times the supposed limit the last time this occurred.  Operating as an island does put the state at an increased risk of blackouts during a summer heatwave or winter cold snap, but we know exactly how to fix this problem and we could do it in under 3 weeks9 by renting portable diesel generators.  Or if we felt like waiting 100 days we could build some more big batteries.

Endless Objections

Looking online I see there are people devoting their energy to arguing that 100% renewable energy is impossible.  But, try as they might, I’m certain they’ll never match the 20 percenters in either numbers or sheer idiotic stamina.  The time for this type of idiocy has passed.  While we currently don’t know the best way to get electricity generation to zero net emissions, it’s not possible to make a good faith argument that it’s technically impossible.  Given the falling cost of renewables and energy storage, as well as the low costs of various estimates, there is also no real economic objection either.  Not unless you think CO2 is just plant food without any drawbacks.  In which case you’re probably a plant yourself.  Specifically, a vegetable.

Rather than shifting their immovable line in the sand from “more than 20% is impossible” to “100% is impossible” I expect the current objectors will just fade away and we’ll pay them no more attention than we do to people who occasionally cry out that fluoridated water is a plot by Satan or that the Kaiser stole their string.  They’ll soon find something else to complain and feel self-righteous about online or, once everyone realizes the internet is just a passing fad, go back to kicking dogs and pissing in wells or however they used to amuse themselves.


  1. Intermittent renewables refers to wind and solar power.  This term distinguishes them from dispatchable renewable energythat can be turned on and off as desired such as hydroelectricity and biomass.
  2. I suspect the election of Donald Trump had something to do with it.  It used to be important to blowhards to act as though facts and figures were on their side, but once their paragon became President they followed his lead and cast them aside.
  3. By prominent, I mean other than in bitching online.  Instead they could be well known for bitching in newspaper columns or on radio.
  4. The modern term for dismissing evidence in favor of your gut feeling is derp.  These characters herped a flerp of derp on the topic.
  5. The modern preponderance of derpy engineers is quite a change from my grandparent’s day.  Back in their time if a newspaper wanted an ill-informed opinion from a well educated person they usually got it from a medical doctor.
  6. All the electricity generated in Australia for commercial, industrial, and residential use came to 10,240 kilowatt-hours per person last year.  A 7 kilowatt, 20 panel, solar system can produce that much.  Australia has enough roof space that — if we went nuts — we could generate electrical energy in excess of Australia’s current consumption from roofs alone.
  7. Some put their own spin on it and declared more than 10% or even 4% was impossible.
  8. Meanwhile, Denmark has two completely separate grids, one connected to Sweden and the other to Germany, but they’ll be joined up the long way around when the North Sea Link interconnector between Norway and England opens next year.
  9. When Tasmania’s Basslink interconnector broke and the island was islanded they had large diesel generators shipped in from the Philippines inside of weeks.  This probably caused more blackouts in the Philippines than they prevented in Tasmania.
About Ronald Brakels

Joining SolarQuotes in 2015, Ronald has a knack for reading those tediously long documents put out by solar manufacturers and translating their contents into something consumers might find interesting. Master of heavily researched deep-dive blog posts, his relentless consumer advocacy has ruffled more than a few manufacturer's feathers over the years. Read Ronald's full bio.


  1. Ken Hungerford says

    Unfortunately there are more than enough morons in all walks of life. They need to be neutered before becoming of children-producing age so they do not multiply. It is depressing that so many people are totally incapable of critical thinking nor, it would appear, of reading.

  2. Ian Thompson says

    Let me say at the outset, Ronald – I am a Professional Engineer who has never worked in the Energy Industry, and who has never held an opinion one way or another that 20% represents a “hard limit”.

    But we do technically know, definitely, that distributed intermittent sources of power present unique challenges in many ways. For example, the need for storage, transmission upgrades, more FCAS, etc. I’ve always taken the view that we will deal with the issues, either ahead of time, or in the fullness of time as these issues are identified or become a problem. The increased penetration of rooftop PV has certainly RESULTED in voltage rise, even if the CAUSE is inadequately low line impedance – the lines and transformers were never originally designed for this new service, and will require expensive upgrades to accomodate the increasingly distributed and “spiky” generation of power. Same sort of thing goes for storage, HV transmission infrastructure, and FCAS.

    However, with the utmost respect because I value your integrity on these matters, I feel you are exhibiting quite a high level of “confirmation bias” in your comments, making some of your arguments somewhat suspect.

    Firstly, have we even reached the 20% renewables level yet? I have been monitoring the Supply & Demand widget for a long time now, and can say with some confidence that the “mode” of power supplied from black coal, brown coal, and natural gas on a daily basis is around 70-75% during the day, and 80-85% during the night, of total demand. Sometimes a little less, sometimes a little less. The Big Battery contributes bugger all. The total renewable content, including Hydro, therefore on average barely reaches 20%. May even be lower in winter, when the sun don’t shine, if the wind generation doesn’t pick up the tab. Sometimes a LOT lower, seldom much higher.

    To me, stating SA exports renewable energy during the day, and gets it back during the night (instead of storage) – whereas the imported energy is, of necessity mostly non-renewable – smacks of biased and illogical thinking.
    I feel you have “cherry-picked” this example to make a point that is neither true, nor relevant – at the very minimum extremely misleading. In my opinion, you cannot claim performance attributes, for a “non-closed” system. After all, SA has been forced to upgrade it’s interconnectors, and also rent diesel generators (yes, I did note the use of liquid fuel on the widget – but haven’t included that in the non-renewable generation figures).

    Yes – we will deal with grid-stability and intermittency issues, storage, and line upgrades – but in my view these should correctly costed to renewables, even if some lines have reached the end of their service life and require replacement anyway. I’m certainly not arguing there is a 20% limit – only that there are of course numerous indirect costs associated with renewables penetration. And of course increasing population will likely require even more in the way of infrastructure.

    None of this implies we cannot “make a buck” by installing rooftop PV – as I did 4-5 years ago.

  3. Lawrence Coomber says

    Great article Ron.

    Yes the 20% naysayers have evaporated into the ether.

    There were some practitioners in the energy industry however both brave and visionary enough, who nailed their RE percentage visions and aspirations “to the masthead” many years ago, by pole vaulting over the miniscule 20% you refer to and went straight to the top of the renewable energy pyramid to 100%.

    My company was the first in Australia to aim high [100% Renewable] in fact by registering a trading name with ASIC of GO 100 PERCENT RENEWABLE in 2009 and followed with registering trading name 100 PERCENT SOLAR in February 2010; which is our current registered trading name with the Clean Energy Regulator.

    100% Renewable was quite a lofty ambition 15 years ago, but we have persevered and achieved precisely that in many 100% Off Grid Solar and 100% Solar Pumping Solutions in over 8 countries to date.

    However we all realise that the challenge ahead for high percentage Grid Renewables penetration is a slightly different kettle of fish!

    Lawrence Coomber

    • John Crocombe says

      Remembering we have to have the bauxite and copper etc dug out of the ground and shipped to China, then returned to us as a boat load of solar panels (and possibly wind generators), how probable/possible/affordable is it to have a 100% solar (or even a renewable mix) powered, end to end, solar panel manufacturing process in the foreseeable future?

      Should we build solar panel manufacturing plants in countries like Australia, to make the most of the available solar radiation?

      • Lawrence Coomber says

        John no we should not.

        The reasons are economical (commercial viability is a better term).

        I am assuming you are old enough to recall the saying “horses for courses” John. It is definitely accurate, and that is coming from my considerable engineering and manufacturing experience for over 50 years plus having small water and power technology manufacturing facilities in Qld (35 years) and Wuxi China (12 years).

        Lawrence Coomber

  4. If a computer virus stoped special people watching cat videos online that would be devastating

  5. They haven’t disappeared, sadly. They now whine to me about how my EV pollutes more than their Mustang, or that shutting down the coal stations would put so many people out of a job that our economy would collapse.
    And these people vote. ???

  6. This story might be better placed to discuss the vested interests whose only intention was to see off renewable energy. It was well understood 10 years ago that the fossil fuel industry was financing bloggers (trolls) to sew doubt about renewable energy so that citizens of all countries would turn their back on renewables and stay with the tried and trusted dirty energy which is destroying our planet as we speak.
    One only needs to look at the leaders of the pack and the Murdoch media outlets have been waving the coal flag since we started installing solar on our rooftops. Never stopped. Murdoch recently claimed he was not a climate denier as well which would have brought about head shaking and uproarious laughter from many of us.
    The 20% deniers SHOULD be named and repeatedly shamed. Its the only way to destroy the credibility they claim to have when in fact they are messengers meant to keep the status quo. The death of the planet? No worries…as long as the money to the top end of town keeps flowing. That’s what it is all about.

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