Engineers Explain Why Wind & Solar Inevitably Destroy Reliable & Affordable Power Supplies

April 1, 2023 by stopthesethings Leave a Comment

South Australians, Californians and Texans know what comes from an overreliance on the unreliables, having suffered numerous weather-related load shedding and mass blackouts.

Increasing dependence on chaotically intermittent wind and solar is the price we’ve paid for allowing ideology to ride roughshod over sound engineering and solid economics.

Once the engineers were relegated to the back office by wind and solar-worshipping ideologues equipped with sociology or arts/law degrees, the end of reliably delivered power at affordable prices was inevitable.

Now, here we are. With power prices rocketing out of control, and a grid teetering on the verge of total collapse. And all thanks to a band of zealots that can’t tell the critical difference between ‘energy’ and ‘power’; that claims that wind and solar’s hopeless intermittency can be cured with a few giant lithium batteries; who berate anybody who mentions sunset and calm weather and renewable energy in a sentence; and who find mathematics, logic and reason all a deathly bore. All the things that engineers are trained to live and breathe, are simply dismissed as old-school nonsense.

Well, STT thinks it’s high time the engineers were given some overdue air-time. So, we’ll hand over to Chris Morris – a semi-retired power station engineer from New Zealand, and Russ Schussler – an electrical System Planning Engineer, and Retired Vice President of Transmission Planning at Georgia Transmission Corporations for a rundown on what the ideologues have done to our once reliable and affordable power supplies.

Australian renewables integration: Part 1
Climate Etc.
Chris Morris and Russ Schussler
2 March 2023

Australia is transitioning from a coal fired generation system to one based on solar and wind. There is an accelerated program to do this driven by both major political parties. There has been a lot written about the developments, mainly as advocacy, and many relevant facts are not mentioned. The proponents see the transition as world-leading while the skeptics believe the country will become the crash test dummy proving it won’t work. Already there have been major issues. Those in themselves and the remedial actions needed are harbingers that increasing penetration is likely to lead to a very expensive and unreliable electrical energy system.

The country isn’t the image the travel posters promote. More than 80% of Australians live within thirty miles of the coast and an even bigger percentage in urban areas. The big cities are hundreds of miles apart around the continental edge. These factors have had a major influence on their grid. Until quite recently, the system was primarily supported by large multi-unit coal fired power stations, located next to the coalfields. The transmission lines ran from them to the cities they served. There was very little interconnection. This was influenced by the very parochial political system.

Australia is a federal system, with six States and several Territories. The States jealously guarded their rights and had regular disputes with both their neighbours and the Federal Government. Interstate rivalry can go beyond a joke. Each State originally ran their own electricity system. Gradually this expanded and interconnectors between States were put in. As well as the AC lines, there are three DC interconnectors including a near 200 mile undersea cable joining Tasmania to the mainland. The interconnectors are ties between the State grids allowing interstate flow, but they often act as chokepoints.

In the 90s, the National Electricity Market (NEM) started. The name is a misnomer. Western Australia, about a third of the country, isn’t a part of it as it is too far away to link. Neither are the numerous isolated towns not connected to anywhere. Part 1 deals with grid as it is now in the Eastern and South-eastern States.

The management and operation of the electrical system is complex and mainly market driven. At the top is the Energy Regulator, a federal agency enforces the rules, monitors the markets, sets the revenue for the monopolies and is the arbitrator for disputes. Together with them is AEMC (Australian Energy Market Commission) who make and amend the rules but they can’t propose them.  The federal AEMO (Australian Energy Market Operator) is the System Operator, running their electricity (and gas) markets. The market is run on a merit order dispatch, subject to load requirements and constraints. Negative pricing is allowed to ensure must run generation. For every trading period, originally half an hour but now five minutes, the generators submit a power and price. This can be graduated. This is arranged in increasing price forming a total MW versus price stack. The price paid to all dispatched resources is where the load line crosses this merit order stack. Some plant may be constrained on or off, regardless of their place in the merit order. There are also a number of secondary markets for services like reserves and frequency control.

Most of the generators are owned by companies which seek to run at a profit. They can connect to the grid if they comply with the rules. There can be problems connecting if there are no local lines or the ones there are overloaded. They generate when dispatched. For those like wind and solar who are semi-scheduled (a euphemism for unreliable) there are special rules around their bids.

Each State has a transmission grid company that owns and operates their high voltage network. There are distribution companies for the low voltage networks that have territories for which they are responsible. For example, NSW (New South Wales) has three of these. Both Transmission and Distribution are natural monopolies so are run as regulated ones.

There are a myriad of electricity retailers. Some are generator based retailers (gentailers), providing a customer load for their generation. Most retailers have longer term contracts with generation companies for their load requirements. There are niche suppliers who run on spot market prices but have backup hedges for their load requirements. Some market gas or internet as a package. The NEM supplies around 9 million customers – they are the group that ultimately pay the cost of both operation and capital development.

To this market has to be added the uncontrolled domestic generation by solar panels. These make up a significant and increasing part of the generation base. In one state one day, they provided over 90% of the instantaneous generation.  The installations are supported by subsidies and generous feed-in tariffs. Most households do not have batteries.

AEMO does the forecasting. They look at factors like government policy, load predictions, generation development plans, system security requirements and the like. They use these to put out a variety of regular reports; some general, some specific, detailing what changes need to be made. The transmission companies are responsible for execution and to get funding approval from the regulator. As well as these, if a major incident occurs, they will put out a report detailing what happened, why and what changes need to be made. These often feed back into the other reports.

That is how it all fits together. Needless to say, the bureaucracy cost is high and there is a lot of employment for administrators and lawyers. The maps here show the location in each State of the transmission system and generators, both existing and proposed ones. The NEM supplies around 9 million customers – they are the group that ultimately pay the cost of both operation and capital development.

Cost to consumers
The renewables are subsidised to varying extents. Because it can be present at different levels and through different forms right down to the domestic level, it seems no one is exactly sure how much renewables are subsidized. However, the power price has risen over the 40 years at twice the rate of inflation with prices really taking off in 2007, coincident with an increased renewable energy target. The authors are unaware of any detailed breakdown of exactly what has caused this rise other than the correlation with RET (Renewable Energy Target).  The power price is still going up. We note the Ukraine war was blamed for part of the rises, even though Australia imports no electricity or thermal power station fuel.  In contrast with reality, the AEMC just two years ago, and others more recently, predicted power would be getting cheaper by now. Even if it is not in the power bill, the price of these subsidies comes from somewhere and eventually are paid for by the taxpayer.

[Note to the authors: the direct subsidy is the value in the Renewable Energy Certificates (or rather Large-Scale Generation Certificates) awarded to wind and large-scale solar generators for every MWh dispatched to the grid. The cost of an LGC is usually contracted at around $85 with the retailers, who purchase wind and large-scale solar to avoid the shortfall penalty charge, and the cost of the LGC is incorporated in retail power bills and paid for by all power consumers. For more detail see STT’s post: HERE]

Where the Renewables are currently
Wind and solar, the unreliables, are now a significant part of the current NEM generation but the backbone is still coal – over 60% of the energy. Wind is less than 15% and grid solar 5%. The snapshot below when the sun wasn’t shining shows the contribution coal still makes.  There is also the significant presence of domestic PV.  Because it is mainly behind the meter, there is no accurate data on its precise magnitude. But scaling up the contribution of grid solar and allowing for less efficient installations, it would be in the order of another 10%. However, even at those levels, the intermittency and unpredictability has had major detrimental impacts on power stability. Note the instantaneous power contribution can be a lot higher that the numbers quoted above. This article mainly looks at just the broader problems of its unpredictability.  Later postings may cover a more detailed analysis of some specific problems that have occurred so far.

Management of the grid on a day-to-day basis depends on reliable generation and dispatchability. The renewables offer neither. For wind, there is often the mantra that the wind is blowing somewhere. The actual data does not back that up. A skeptic has for a number of years compiled the daily wind generation on the NEM. The results are revealing. The graph shown below is for just one month, June 2022. There is a synchronicity in the output of all the windfarms. To cope with the drop in those declines from wind, that is a lot of power that needs to be quickly ramped up.  If the wind isn’t blowing and it is night-time, where will the energy to make up the dip come from? The mainstay 400MW+ coal units that form the background of the energy supply can take three days to get to full load if cold.

Solar can be just as bad. On 1st and 4th July, 2022, the power from solar those days in Queensland was only a small fraction of what it had been the previous week or so. On the 4th, there was a cloud bank over all of the eastern half of the state all day and little wind production as well. The interconnectors from NSW were at rating with imports and the market price was at the maximum $15,000/MWh.

Proponents of the renewables boast about how places like South Australia (SA) achieved near 100% renewable energy generation, often around the middle of the day, implying they could do it all the time. What they don’t say, because it spoils the narrative, is a lot more instructive. Look at the generation profile below of one such day. They had to keep the gas turbines on to provide inertia. These had to generate most of the load before dawn and at dusk because the wind wasn’t there. The battery provided very little. The balancing interconnectors to Victoria that allowed a nearly 20% export of coal fired power to come in were important if not essential. Without the gas power and the Heywood line, SA would have been in real trouble.

Even on a “normal” day, the merit order in SA is akin to a switch. When the sun is out and the wind is blowing, the merit order is in negative pricing. When it’s not, prices go up, often around $400/MWh. That raises costs for the distribution companies which pass it on to their customers.

Heywood’s interconnector plays a lot bigger everyday role in buffering SA’s erratic generation than renewables proponents will admit. In the right conditions, up to 40% of the State’s load comes in through its lines. That stabilises its voltage as the frequency is locked onto that of the NEM. There is a smaller interconnector from north-western Victoria, but this is DC so it has a lot less of a role. Heywood’s benefit was demonstrated during an islanding outage in November. During the outage, it cost the grid operators, in just two days, $22M just to provide Frequency Control services. These are what used to be called governor control on grids with a lot of inertia and big steam turbines. On modern grids, many thermal plants, especially gas turbines can run in this mode. Things often happen a lot faster with less conventional generation, so the corrections of frequency control have to be sped up. Grid operators promote batteries are capable of this function, but that is making a virtue out of a necessity. All those islanding costs will need to be paid by either the power consumer or the taxpayer. That is why SA has the most expensive power of any of the mainland States in the NEM.

The examples above show the unpredictability NEM grid operators have had to regularly cope with. It is relatively easy to match load and generation when conditions are just right. However, it generally takes a very fine balance backed up by a lot of very expensive plant infrastructure. Much of it is not needed for day-to-day operations. However, when things go wrong, they can turn catastrophic in a very short time. The grid power supply to major infrastructure within a city maybe 99.99% reliable, but can it cope with the power unpredictably being out for an hour a year which that number is? Reliable electricity isn’t just a nice to have for modern life, it is essential.

Forty years ago, Australia had an electricity system delivering cheap, reliable power. That is no longer the case. Development and change have been driven by politics and dogma, not engineering and economics. Things that work are being replaced by that which looks good to virtue signallers, especially to those that don’t understand the issue. Prices have risen a lot faster than inflation.  Even then, the number on the power bill is probably not the full cost as there are hidden ones. The authors are unaware of any recent study of the price that takes into account or even identifies all the subsidies. However, for the money expended, they should have had a capable, robust, gold-plated system. It isn’t. The system staggers from crisis to crisis, the solution usually being more rules, market interventions and invariably, a subsidy. The price of electricity fluctuates between glut and scarcity, even on a daily basis. Large industrial users like smelters are downsizing, offshoring, or getting another subsidy. Australia used to be referred to as the lucky country. That may no longer be the case.

Next up:  “Australia Part 2; A Grid revolution around the Corner? Or Just the Madness of a Crowds?” Will look at efforts within Australia to reduce the need for synchronous generators and allow for high penetration of renewables.  Additional posts may follow covering other issues within Australia.

Australian renewables integration. Part 2
Climate Etc
Russ Schussler and Chris Morris
8 March 2023

Many are looking towards Australia and seeing bold, innovative steps to increase the penetration levels of wind and solar resources. A grid revolution around the corner? Or just the madness of crowds?  This post discusses what we can discern from their efforts so far.

Major New Innovations in Australia?
Part 1 covered renewables’ impacts so far on the major power grid in Australia. Many are inspired by this headline:  South Australia may be first big grid in world to go without synchronous generation. The article begins by noting:

South Australia – already leading the world in the uptake of wind and solar and operating its grid at high levels of renewables – could be the first gigawatt scale grid in the world to operate without synchronous generation… South Australia is unique in the world because it is the first gigawatt scale grid to operate at such high levels of wind and solar, which in the past year have accounted for 64 per cent of local generation, according to AEMO.

Reports are that South Australia is set to become the first big grid to run on 100% renewables.

In far away Western Australia, with a smaller independent grid, is setting records for wind and solar as well. In 2025 they believe there may be enough wind and solar to power the grid entirely by renewables, for at least half an hour. On October 162022 there was more than enough available wind and solar to match local demand there.

“AroundTheCornerism”
Identified problems associated with a net zero grid are often inappropriately dismissed with some reference to work being done somewhere, or referencing the claims of academics. Frequently industry changing innovations have appeared poised to emerge just “around the corner”. Despite the enthusiasm of their boosters, these just around the corner breakthroughs often tend not to work out very well. The eventual associated complexity and costs of “around the corner” projects often prove crippling. Such claims can be almost impenetrably confusing. “Around the corner” claims are often overblown or misunderstood. Let’s dig a little deeper into the available information here.

Is South Australia a Grid?
First off it should be noted that South Australia (SA) is not a grid in the context of being self-contained and independent. It is a relatively small component of a large grid. The resources on the larger grid were described in Part 1:

Wind and solar, the unreliables, are now a significant part of the current NEM generation but the backbone is still coal – over 60% of the energy. Wind is less than 15% and grid solar 5%. …. There is also the significant presence of domestic PV.  Because it is mainly behind the meter, there is no accurate data on its precise magnitude. But scaling up the contribution of grid solar and allowing for less efficient installations, it would be in the order of another 10%.

The large grid has a significant number of synchronous generators that support the SA system in many ways. As noted in Part 1, generation in Victoria specifically helps buffer South Australia’s already erratic generation through the Heywood interconnection. The large synchronous machines on the neighboring system work to support the South Australia experiment. The hype that this experiment is receiving would be well more deserved, if the greater grid were participating to the same degree as South Australia.

This isn’t the first time that exaggerated claims have been made concerning the ability of an independent grid to run at high levels of renewables, based upon the penetration levels within a limited area of the grid. Not too long ago many pointed towards Germany as showing how a grid could accommodate high levels of renewables. This was a very misleading picture. The physics of the grid does not care who owns what. Synchronous resources from a neighbor’s generators provide support across the European grid, despite differences in language and nationality. Electricity flows quickly, approaching the speed of light, over every potential path to support all parts of the system regardless of who owns what. The German component is supported by conventional generation from neighboring systems including coal resources in Poland.

OK, Not an Independent Grid, But a Good Sized Asynchronous Component of a Grid?

Is South Australia going asynchronous?  Grid experts reading the claim that, South Australia may be first big grid in world to go without synchronous generation, should know there is a trick somewhere, even if they aren’t quite yet sure what the trick is. The trick (besides that SA is not a grid) is that they are not, as a quick reading of the headline suggests, looking at building a grid that doesn’t rely on synchronous resources.

There is a loophole in the argument that grids require synchronous generators. The South Australia headline is capitalizing on that loophole. Four synchronous condensers are needed to maintain the grid without their synchronous gas generating units. These synchronous condensers need to be in place before they remove conventional generation. Synchronous condensers are basically the same as synchronous generators, the difference being they lack the ability to generate power. Existing steam plants can be converted to synchronous condensers by removing the prime mover that powers the unit. The rest of the assembly rotates in synchrony with the grid. Synchronous condensers can provide inertia, voltage control and provide or absorb vars. Synchronous condensers function at the point where generators transition to motors. Synchronous condensers are synchronous machines but they consume power, rather than supply it.

Putting this in context, the SA experiment is not to create an asynchronous independent grid operating on wind and solar, as many perceive. The experiment is addressing how well a component of a large grid  can integrate a large amount of wind and solar, that benefits from the synchronous generators of its neighbors and which has installed special synchronous condensers to replace the synchronous generators that they are retiring,

Is Using Synchronous Condensers to Support Renewables a New Idea?
Not really. Synchronous condensers have been around for a very long while. In Planning Engineer’s first posting at Climate Etc. in 2014 he noted:

Could a power system operating similar to ours be built that relied on only renewable resources? The answer is yes and no. As noted above there are essential system characteristics that most renewables do not supply or supply well. However, a renewable system could be coupled with extensive batteries and other storage devices, large mechanical flywheels and condensers (basically an unpowered motor/generator that can spit out or consume reactive power). These devices could approximate the behaviors of our conventional power system but they would require huge and prohibitive costs.

To be clear, synchronous condensers are great things to have on a grid. They were infrequently used in the past because so many synchronous generators were typically present to support the grid.  Wind and solar are creating a need for synchronous condensers, which have been rebranded as “syncons”. One of the authors has made recommendations in the past at various times to convert retiring plants to operate as synchronous condensers to better support the grid. However, the structures of ownership and cost sharing doomed such strategic considerations. As Australia is judging it worthwhile to incur the full costs of new synchronous condensers, perhaps policy changes could be made to allow even more economic conversion, especially as asynchronous renewables are increasing their penetration levels most everywhere. Often it would make sense to keep old coal plants around to provide both emergency generation and synchronous resources when needed. If that’s not possible, consideration should be given to at least keeping them as synchronous condensers. Part of why neither is being done is that many are proud to virtuously claim that they are shuttering coal plants. When multiple plants are closed by a solitary action, you know little thought is going into the specifics. Beyond that, flawed market and cost recovery schemes are causing many opportunities to be missed.

If others learn from Australia the value of synchronous condensers (especially at low cost from retiring plants), that will be a great thing.

What else is SA doing?
As noted by the market operator AMEO, there are detailed engineering challenges that must be solved before allowing 100% renewables on the grid. “They are undertaking various other improvements to cope with the generation changes. Currently there are plans to spend $12.7 Billion to build 5 new high voltage transmission lines to bolster their system. South Australia also has a strong need for storage to enable frequency control and reserves services. Plans to allow more of the wind and solar output to be used, also include more exotic procedures such as heavier curtailment of power from rooftop PV under certain conditions. Cutting solar at the residential level to allow greater renewable penetration at the grid level (or because of difficulties introduced by dispatch of solar and wind) provides a good illustration of how challenging and overcomplicated this transition might be. This article notes, ”AEMO’s plan to fix the broken energy system seems so simple, but it’s likely to be anything but.”

It is doubtful the current approach can be sustained. Remember that coal is still the major generation energy source in Australia. Continuing and expanding the steps they are taking with increasing grid wide penetration will only compound the costs and challenges. Their “solutions” are not the bold innovations needed for the proposed changes in generation, but rather costly, makeshift, stopgap Band-aids.

Replacing generation, adding storage, adding synchronous machines and complicating procedures will likely harm cost and reliability. Leveled cost comparisons of wind and solar to natural gas are very misleading if they ignore the changes needed to support asynchronous renewables. Proponents of wind and solar want these extra costs to be hidden and paid by others. But if wind and solar require large synchronous machines to enable them to work with the grid, and storage as well, some cost reckoning is due when competing resources include synchronous capability as an inherent part of their design. Renewable advocates can’t continually rely on shoddy cost studies ignoring the huge cost differences associated with competing resources. As wind and solar become more prevalent, the extra costs necessary to address reliability will increase and be harder to hide.

AMEO must realize this, as they have stated their intent to move towards developing the capability for inverter-based resources (like wind, solar and batteries) to provide the functionality they are now seeking from synchronous condensers. The inverter-based work is much less developed and much further away. If it could be made to work it would likely be much less expensive than their current approach. But can it be made to work on a complicated grid?  Nobody is proposing to begin that experiment yet on a large scale. A system primarily dependent on inverter-based support, whether synchronous or asynchronous, would be revolutionary. If that’s where their focus is, the development within Australia would truly be worthy of attention.

Why is the Focus on Changing Resources and not The Grid Needs?
The series “Academics and the Grid” (here, here and here) discussed two different foci of the energy transition. There are two major problem areas:

• Getting energy from renewables instead of fossil fuels
• Having the grid work with intermittent asynchronous renewable resources

It would seem that a grid transformation would need to make progress on these two separate concerns in tandem. The first problem is easier to address while the second is more challenging and becomes increasingly intractable at higher penetration levels of wind and solar. It’s understandable why individuals or groups might choose to address the first problem over the other, especially in terms of personal incentives and rewards. But it is mind-boggling that an entity committed to an energy transition would seek to maximize efforts in regard to changing energy resources while hoping a miracle will occur allowing that energy to be delivered in an economic and reliable manner.

The mismatch between energy sourcing and energy delivery raises challenges in terms of responsibilities and costs.  The decarbonization advisor noted the considerable “wrangling over who should foot the construction bill”.  Some additional interesting quotes from the decarbonization advisor appear in this article.

• “The simple task is to estimate when coal is going to come out of the system — that’s number one”
• “The most difficult thing is enabling the replacement”
• We know that large-scale batteries and large-scale hydro are going to play a pretty significant role.
• “(T)here’ll need to be a role for gas and we know there’s going to be a role for [rooftop solar and battery]”
• “We know there’ll need to be a great deal of attention paid to what happens when that base-load generation comes off”
• “A lot of the markets that will pay for these new sources don’t yet exist”
• “Energy to be ‘unrecognisable”

Except for putting the cart before the horse, these quotes suggest we might agree about a lot. It is simple to take out coal, if you don’t care what happens next. It is going to be incredibly difficult, if at all possible, to enable the replacement.  Significant roles will be demanded from all resources but that may not be enough. A lot of attention needs to be paid when baseload generation comes off, and a lot of challenges without practical solutions will likely emerge.  A lot of needed things needed don’t exist yet and may not ever exist. The energy system may be unrecognizable, maybe because it will no longer resemble an economic and reliable power system.

Evidently, there are a lot of individual short-term incentives in the mix, not tied to any long-term gains for the large population of electric consumers. Clearly many relevant policy makers lack information and expertise in needed areas and are greatly influenced by others who are in the same boat. From an engineering perspective, it seems obvious that to allow increased penetration of wind and solar, neither of the problem areas can be ignored and that progress must be made concurrently with advancements in both areas. You don’t figure out how to land a plane after you have the passengers in the air.

Energy is too important for policy makers to invest in a “field of dreams”. You can’t change the basics of energy supply, then just hope the support system will organically emerge. The largely singular focus and magical thinking may best be explained by those with expertise in the areas of human, group, organizational, political or religious behavior perhaps those with a good understanding of the “madness of crowds”.

Final Thoughts
South Australia’s initial efforts are less revolutionary than they appear. Their efforts instead show the importance and centrality of synchronous machines. Australia is retiring synchronous generators and replacing them with other synchronous machines. This step is not revolutionary. That and the other solutions they are incorporating confirm that a net-zero grid faces considerable challenges. Combined with other planned changes, their overall efforts will aggravate existing reliability trends. AEMO is currently seeing inertial shortfalls and poor system security.  Will the new efforts continue the trends toward a costlier less reliable grid?  The authors believe it is most likely that costs will increase significantly and reliability will degrade considerably even if they do a great job of implementing all the planned changes. Higher energy costs will hurt their consumers and industry while moving manufacturing and industry away from Australia to areas with cheaper (fossil fuel based) energy. The end result may cause far greater environmental harm.

The effectiveness of South Australia’s future plans remains to be demonstrated. It’s not clear how complicated or expensive it may be to implement the proposed changes. Curtailing residential solar to allow greater grid-based wind and solar, suggests that it may be inordinately complicated.  Australia is not solving these problems, or showing how they might be solved, as much as they are just grappling with them.  How well operators will be able to deal with the complexity is unknown. How much this might cost is a complete unknown. How much it costs and how well it operates will need to be carefully considered before declaring this a path to be emulated across other grids and power systems in the future. The work to replace synchronous machines with inverter-based resources is at best in its infancy. Documentation around their efforts shows that concerns about high levels of penetration by asynchronous renewables are well founded. It is premature to declare any kind of victory here. They may find that things are more challenging than they thought.
Climate Etc

Time to get ready for the daily wind & solar challenge.

Share this: