The lurking threat to solar power’s growth

Interesting article on the economics of Solar Power from The MIT Technology Review.

Plummeting sunny day solar prices are undermining the economic case to build more solar farms – and putting climate goals at risk.

by James Temple July 14, 2021

A few lonely academics have been warning for years that solar power faces a fundamental challenge that could halt the industry’s breakneck growth. Simply put: the more solar you add to the grid, the less valuable it becomes.

The problem is that solar panels generate lots of electricity in the middle of sunny days, frequently more than what’s required, driving down prices—sometimes even into negative territory.

Unlike a natural gas plant, solar plant operators can’t easily throttle electricity up and down as needed, or space generation out through the day, night and dark winter. It’s available when it’s available, which is when the sun is shining. And that’s when all the other solar plants are cranking out electricity at maximum levels as well.

After this introduction, the article goes into what’s happening in Cali

new report finds that California, which produces one of the largest shares of solar power in the world, is already acutely experiencing this phenomenon, known as solar value deflation.

The state’s average solar wholesale prices have fallen 37% relative to the average electricity prices for other sources since 2014, according to the Breakthrough Institute analysis, which will be published on July 14. In other words, utilities are increasingly paying solar plants less than other sources overall, due to their fluctuating generation patterns.

Wholesale prices are basically the amount that utilities pay power plants for the electricity they deliver to households and businesses. They shift throughout the day and year, edging back up for solar operators during the mornings, afternoons and other times when there isn’t excess supply. But as more solar plants come online, the periods of excess supply that drive down those costs will become more frequent and more pronounced.

Lower prices may sound great for consumers. But it presents troubling implications for the world’s hopes of rapidly expanding solar capacity and meeting climate goals.

It could become difficult to convince developers and investors to continue building ever more solar plants if they stand to make less money or even lose it. In fact, California construction has already been flat since 2018, the study notes. But the state will need the industry to significantly ramp up development if it hopes to pull off its ambitious clean energy targets.

The rapidly dropping price of solar power has transformed how we think about clean energy. But it needs to still get a whole lot cheaper.

This could soon become a broader problem as well.

“California is a little sneak peek of what is in store for the rest of the world as we dramatically scale up solar,” says Zeke Hausfather, director of climate and energy at the Breakthrough Institute, and author of the report.

That’s because while solar accounts for about 19% of the electricity California generates, other regions are rapidly installing photovoltaic panels as well. In Nevada and Hawaii, for instance, the share of solar generation stood at around 13% in 2019, the study found. The levels in Italy, Greece and Germany were at 8.6%, 7.9% and 7.8%, respectively.

The race

So far, heavy solar subsidies and the rapidly declining cost of solar power has offset the falling value of solar in California. So long as it gets ever cheaper to build and operate solar power plants, value deflation is less of a problem.

But it’s likely to get harder and harder to pull off that trick, as the state’s share of solar generation continues to climb. If the cost declines for building and installing solar panels tapers off, California’s solar deflation could pull ahead in the race against falling costs as soon as 2022 and climb upward from there, the report finds. At that point, wholesale pricing would be below the subsidized costs of solar in California, undermining the pure economic rationale for building more plants, Hausfather notes.

The state’s SB 100 law, passed in 2018, requires all of California’s electricity to come from “renewable and zero-carbon resources” by 2045. By that point, some 60% of the state’s electricity could come from solar, based on a California Energy Commission model.

The Breakthrough study estimates that the value of solar–or the wholesale average price relative to other sources–will fall by 85% at that point, decimating the economics of solar farms, at least as California’s grid exists today.

Read the full article here.

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July 18, 2021 2:10 pm

So, peak solar?

oeman 50
Reply to  BallBounces
July 19, 2021 8:21 am

Too cheap to meter. Hmmm, where have I heard that before?

Curious George
July 18, 2021 2:12 pm

So cheap that it does not need subsidies?

M Courtney
Reply to  Curious George
July 18, 2021 2:53 pm

When it’s around, even if no-one needs it, yes.
Like wind it should be used for something other than electricity generation. Electricity cannot be stored.

Water desalination or moving bulk materials on conveyers, those are some good uses for intermittent energy sources. Maybe long-term tunnel excavation too.

Anything for which the exact time is not important

Rich Davis
Reply to  M Courtney
July 18, 2021 3:57 pm

I can see where desalination might make sense for California, but I think you still need the solar and wind on the grid to be able to make use of sources relatively far from the desalination plant.

It seems like the idea would be to follow the supply, only operating when there is surplus power. Likewise for any other “asynchronous” application that might be able to be set up to consume surplus solar or wind.

One problem here, if we don’t have a desalination plant now, then building one and having it soak up excess generation doesn’t reduce fossil fuel consumption. Isn’t that supposed to be the whole point of why we’d use unreliables in the first place?

What mine or factory can afford to have bulk materials moved at random times if there isn’t a completely automated (labor-free) process?

As far as I’m aware there are already industrial power customers who agree to having interruptible supply in return for lower rates, but this is usually for extreme peak loads, not a daily routine, and often those customers may have diesel generators for the times of power interruptions.

David A
Reply to  Rich Davis
July 18, 2021 9:05 pm

Rich, I think you are correct, the only way to make this nonsense a bit less nonsensical, is to manufacture use for daytime excess; desalination yes, more EV cars plugged in during the day, either at home for the retired, or at stations, built by whom, how many, etc… while people are at work; and possibly other poorly efficient energy storage systems etc…

However this does little to help the 4:00 PM to 9:00 PM surge when production is most needed, the sun is setting, and glass off is creating great waves, but wind whimpers. It still won’t work without massive prohibitively expensive storage.

Reply to  David A
July 19, 2021 1:59 am

I guess an EV *is* the storage….. tricky to scale up, but perhaps its a solution at local level. Not sure if it works on an individual household level – how many Pos required to charge your EV ?

David A
Reply to  mark
July 19, 2021 3:51 am

Driving a RAV 4 plug in hybrid , so the 18 KWH battery needs about 14 KWH 4 days a week.
While not a fan of subsidies for solar or EVs, I also am not a fan of government programs I never voted for running up my electricity bills to 350 to 400 per month. So I have both. My three times a week 125 mile round trip is giving me the equivalent of 70 miles per gallon with the EV almost free from the solar. ( cost wise compared to a 25 mpg ICE car with $4 a gallon gasoline)
So the slow charging use about 12 amps. I save the last 3 hours for am charging just before I leave. ( battery life) So the car uses about 140 KWHs monthly that would otherwise go back to the grid, when the grid does not need it.

Rich Lentz
Reply to  David A
July 19, 2021 7:40 am

How do you drive your EV to work and then charge it there unless the place you work at has charging stations for each vehicle? Who is going to pay for all of these charging stations? Do you install enough slow, low current units for every parking spot, limiting the expense of the high cost of the power upgrade, or a limited number of fast charging stations with an assigned charging period? What do they do in city areas where there is only Public Parking? And I have at least twenty other questions like this.

David A
Reply to  Rich Lentz
July 19, 2021 11:14 pm

Rich, did you not read my comment?
“ more EV cars plugged in during the day, either at home for the retired, or at stations, built by whom, how many, etc…”

I have the same questions. If the excess power is there, a real cost exists to utilize it. You can likely have break even charging at a very big WAG of 30 cents a KWH. 3.5 miles per KWH is perhaps reasonable.

Rich Davis
Reply to  David A
July 19, 2021 3:24 pm

Yes I agree. And as others pointed out, the desalination plant now takes 4x as long to pay back if you refrain from running it except when there’s a surplus of power.

You won’t only run it when there’s free power. If you paid for the capacity and you can sell the water, you want to use the capacity.

So now all you have done is add more demand on the grid and you’re right back where you started but with an even larger need for backup and storage.

Reply to  M Courtney
July 18, 2021 4:38 pm

Water desalination or moving bulk materials on conveyers, those are some good uses for intermittent energy sources. Maybe long-term tunnel excavation too.

Industrial scale desalination plants cost a pile. It is not economic to have all that capital sitting around waiting for sunlight to operate – even if the power is free. There are small scale passive units that could be economic in remote locations.

Same thing with materials movement. Very high capital cost that would be uneconomic waiting for sunlight to operate.

Rud Istvan
Reply to  RickWill
July 18, 2021 5:27 pm

The inherent problem of intermittancy. Even if solar electricity were free (it isn’t) desal capital demands 24/7 operation. 8 hours solar per day means 24/8=3x the capital amortization cost per gallon water. And peak solar isn’t 8 hours/day even in SoCal.

Reply to  Rud Istvan
July 18, 2021 7:00 pm

The big batteries in Australia get paid to soak up solar power to keep the grid stable. So solar electricity in Australia is actually better than free. If nothing soaks it up then it has to be shut down.

All new solar installations in South Australia require the ability of the grid controllers to shut them down. That is a better option than separating the owner from the grid.

Rooftop owners with solar are now a powerful lobby in Australia. Any effort to get an economic solution is thwarted by that lobby to maintain an income from the rooftop solar.

Reply to  RickWill
July 18, 2021 9:45 pm

The big battery at Hornsdale can buffer 70 MW for a little over 10 minutes. On the scale of the grid, that’s minuscule.

Reply to  meab
July 19, 2021 12:03 am

The capital cost of the battery was recovered in two weeks operation in 2020 when the SA-VIC interconnector was down.

The battery is rated at 100MW and is significant in terms of the SA grid stability where typical demand around 1.2GW and lots of WDGs going up and down in output.

Reply to  RickWill
July 19, 2021 7:24 am

Your right that the Hornesdale/Tesla battery can make a motzah providing FCAS to the grid but that’s because the unreliables created the very problem in the first place. That’s simply first adopter bonanza that runs into the fallacy of composition problem when consumers want dispatchable power at the correct voltage and frequency 24/7/365.

They of course get that with remaining coal power for as long as they can exhaust their capital but increasingly with expensive gas peaking plants that must make hay when the sun don’t shine and the wind don’t blow. Naturally they’re paying twice which is why there’s that correlation twixt lots of unreliables and expensive power bills around the globe.

Battery storage doesn’t cut it for all these mums and dads trying to get an earn out of increasingly shrinking FITs but therer is a solution to the Green overlords getting it wrong and needing to fess up about that. Solar can be used to heat an economic electric storage HWS and any spare to aircondition the home for the occupants’ return-
Can Diverting Solar To Air Conditioning Help Reduce Overvoltage? (
Hot Water PV Diverter Comparison Table (
As for all the EVs they’re supposed to be driving and charging at night at home get off the hallucinogens and into nukes.

David A
Reply to  RickWill
July 19, 2021 3:56 am

Why is that better then separating them ( assuming you are talking residential solar) from the grid?

How expensive is it to build residential solar so that it can be grid connected or separated as needed?

Reply to  RickWill
July 19, 2021 4:03 am

Imagine that, people hooked on OPM (Other People’s Money) demanding that the subsidies not be cut.

Reply to  RickWill
July 19, 2021 4:04 am

Big batteries that are only necessary because of solar, make solar better than free?
I guess double the subsidy is always good.

Reply to  RickWill
July 19, 2021 5:02 am

How much did the batteries cost to soak up the “free” solar? How long do the batteries last and what do you do with them when they reach the end of their lives?

Barnes Moore
Reply to  RickWill
July 19, 2021 5:51 am

That’s a question I have. My understanding is that the batteries in Australia do what you suggest – maintain grid stability, not provide actual back-up power. I am no electrical engineer and have some difficulty grasping some concepts. Can you clarify further if the batteries are actually used for back-up power or if their use is mainly to keep the grid frequency stable?

Reply to  Barnes Moore
July 19, 2021 12:15 pm

They keep the grid from crashing while the real power plants adjust to the changes.
The question then becomes, what happens when they no longer have any real power plants backing up the solar farms?

Reply to  Rud Istvan
July 19, 2021 11:48 am

Use the “extra” solar power to store compressed air in the day, then aim air-nozzles to blow compressed air at wind-turbines blades at night. 🙂

Rich Davis
Reply to  beng135
July 19, 2021 4:25 pm

Oh yeah. So you know somebody’s gonna think that sounds reasonable.

Jake J
Reply to  M Courtney
July 18, 2021 5:52 pm

Before they do the desalination thing, they should fix the leaky water mains. But that’s too cheap, too sensible, and not glamorous.

Reply to  Jake J
July 19, 2021 2:25 am

Australia has a few mothballed desalination plants lying around, a leftover from a few years ago when their climate science experts said they would experience droughts for centuries to come. And the people believed them.

Reply to  M Courtney
July 19, 2021 2:08 am

The most obvious thing to do with the excess of solar generation is to use it to produce hydrogen gas by electrolysis

Reply to  Martin
July 19, 2021 9:06 pm

“The most obvious thing to do with the excess of solar generation”

… is to stop building solar generation

Rich Davis
Reply to  M Courtney
July 19, 2021 3:53 pm

Even though I disagreed, you make me wonder though.

Right now I can’t control my average cost per KWh by shifting my usage to match supply. I can only cut my cost by reducing my KWh. So I have no incentive to cut demand when supply is tight and also no incentive to arrange my day to use power when the grid has too much. (Other than Green piety of which I am notably deficient).

I have a hunch that a lot of consumers would find ways to take advantage of intermittent power surpluses and avoid times of peak demand if they had the incentive of a price signal. If during surplus, power were free and appliances were able to be programmed to shut off when the price exceeds some threshold (not necessarily zero), I can foresee that demand could be shifted to some degree.

People might well buy appliances that run intermittently if power is sometimes free. Here I’m thinking of dishwashers, and washing machines, maybe clothes dryers, too.

Even a refrigerator could be designed to be a hybrid ice box, making its own ice when power is free and melting ice when power is expensive.

A freezer could cycle colder than normal when power is free and not need to run as much when power is pricey.

In winter, an extra large tank of water could be heated when power is free and circulated when power is expensive, in lieu of the active heating circuits.

All of these ideas make appliances more complex, more expensive, less reliable, and generally less convenient. So I don’t think we should do this, but it’s an interesting engineering problem.

Reply to  Rich Davis
July 20, 2021 4:58 pm

I know a guy with a series of groundwater wells that are used with a geothermal heat exchanger to either cool or heat the house; all run via solar cells. It is an interesting solution for the home, or I can just pay $60 per month for electricity in my home.

The capital costs for the wells, heat exchanger, battery backup, and solar plant seem excessive in my opinion.

Reply to  Curious George
July 18, 2021 8:23 pm

Negative wholesale prices and high retail prices! All these super smart scientists, science writers and economists can’t work out why?

Reply to  Curious George
July 18, 2021 11:56 pm

Solar and wind are free remember .
Never mind the capital costs of installation and transmission , all us poor people and our kids can pay that off in a lifetime .
Politicians only worry is their term of government , the bureaucrats have a job for life .
Any blackouts are obviously climate change .
Give us more money .

David Dibbell
July 18, 2021 2:14 pm

Wow, who could have seen this coming? Allow solar farms and wind turbines to inject cheap kWh into the grid whenever it is being produced, with no responsibility to supply any energy at all when it is dark or calm: What could possibly go wrong? It was always a parasitic concept, diverting revenue from reliable sources. How about changing the rules so that a solar or wind source must also provide or contract for a certain amount of alternate capacity?

Reply to  David Dibbell
July 18, 2021 7:08 pm

The word “cheap” needs to be replaced with “subsidised” to make the statement accurate. There would be fewer weather dependent generators if they were not subsidised.

In fact, WDGs impose extra costs on any grid. The only economic installations are associated with displacing oil as a fuel source or extending the duration of perched water storage in a hydro dominated system. There is some potential to offer economic merit for fuel reduction in regions that rely heavily on open cycle gas generators; not sure if they are there yet though!

Joao Martins
Reply to  RickWill
July 19, 2021 1:59 am

“Cheap” or subsidised”, David Dibbell has accurately classified it:

“It was always a parasitic concept, diverting revenue from reliable sources.”: This is the simple, plain truth.

David Dibbell
Reply to  RickWill
July 19, 2021 3:40 am

You make good points, but consider that once built and operational, the marginal cost of the next kWh injected from solar or wind is near zero, hence “cheap” whether subsidized or not.

David A
Reply to  David Dibbell
July 19, 2021 11:23 pm

I can assure you business developers do not think that way, and for good reason.

P Wells
July 18, 2021 2:35 pm

Hard reality is tough for a lot of people to face up to.

Jake J
Reply to  P Wells
July 18, 2021 5:53 pm

Especially when you can blame any problems on The Evil Trump ™

Citizen Smith
Reply to  P Wells
July 19, 2021 9:04 am

Is this a reality too: Don’t solar cells absorb energy from the sun more efficiently than what ever surface they are mounted over. Don’t green foliage, rock, dirt roof tops, whatever reflect energy back out to space at higher rates? This is the albedo effect minus whatever green house gases bounce back versus the most efficient artificial surface that can be designed to absorb energy and trap it on the surface. If that’s true, don’t solar cells cause global warming?

Reply to  Citizen Smith
July 19, 2021 12:17 pm

From what I’ve seen they certainly cause localized warming, so that seems to be a valid question.

old engineer
July 18, 2021 2:36 pm

Just had to read the first few paragraph of the Breakthrough Institute’s report to find reason for the report:

“As a result, we find that some degree of future subsidies — either in the form of current tax incentives or future nominally technologically-neutral mechanisms like carbon pricing or a clean energy standard — will likely be needed to sustain cost-effective deployment of the high levels of solar over the next three decades….” 

So there it is – subsidies forever.

Reply to  old engineer
July 19, 2021 1:40 am

In the UK the renewables have priority access and are paid in rates far exceeding wholesale. If there is too much juice at certain times, they are paid to turn off (usually at an obscene rate per MWh foregone).

The result of these shenanigans is larger electricity bills for consumers, but naturally the breakdown of the bills is not shown on them. (Though if you look hard enough, it is possible to find out.)

July 18, 2021 2:39 pm

In Australia the national electricity market also has to cope with problems from intermittent wind and solar. During the last week, dispatachable generators had to vary output daily from a low of 13.4 GW to a peak of 27.2 GW as wind and solar delivered a low of 1.4 GW and a high of 10.4 GW. As a result, 30 minute spot prices vary from a low of zero to a high of $100/MWhr, average $82. The grid continues to cope because of legacy hydro and peaking gas generators. But the warning signs are there if wind and solar increase from their average contribution of 22% towards 50% by 2030, and then “net zero” by 2050.

Reply to  Robber
July 18, 2021 3:21 pm

I know it would be rejected outright by wind & solar acolytes, but Shirlley the proper way to account for wind & solar contributions to grid electricity needs is kw/hrs DISPATCHED.

(Not nameplate capacity or kws generated)

Reply to  Mr.
July 19, 2021 1:32 am


The problem with counting only generation is that a lot of it is generated when its not needed or even usable. Its useless.

Demand is, say, 100 units. We generate in total 150 units. Of this, 80 is conventional and 70 is renewable. But all we can use of the 70 is when its delivered during the peak daylight hour period, namely 20.

The rest is totally useless. So what we have to report is usage by generation type. Anything else is misinformation.

Reply to  Robber
July 18, 2021 4:50 pm

As a result, 30 minute spot prices vary from a low of zero to a high of $100/MWhr, average $82. 

Not quite correct – wholesale prices are often negative.

Negative spot prices continued to occur at very high levels in South Australia (16.8% of the time), and Victoria (10.3%). In South Australia, the average spot price during peak solar production (between 1000 hrs and 1530 hrs) was negative $12/MWh.

Coal generators now bid blocks of power near the floor price of minus $1000 to squeeze out weather dependent generators. The WDGs cannot tolerate negative prices for very long so they voluntarily curtail output. The coal generators catch up when the evening peak hits and they price just under the cost of gas so they remain scheduled.

Coal generators have got smarter in their bidding. However all generators are struggling to make money. Households with rooftops are doing OK.

Reply to  RickWill
July 18, 2021 5:14 pm

Indeed. This paper explains the distortion and contortion going on in south-east Australia with negative spot prices.

Reply to  MACK
July 18, 2021 9:41 pm

The lower wholesale prices are not reflected in retail prices for some of the reasons given in that report. Some not mentioned:

  1. AEMO have rising costs associated with managing the mess; running at about 12%pa increase.
  2. The cost of stability goes beyond just ordering gas plant to run. There is the cost of a big battery to recover and the cost of new synchronous condensers to recover.
  3. When connected generators are far flung and operating at 30% capacity, it takes an order of magnitude more transmission infrastructure to deliver that power.
  4. South Australia relies on Victoria to act as their current biggest battery. They are now massively upgrading the interconnector with NSW so they inflict the same economic harm on the NSW network as they have done to Victoria. The interconnector comes at a substantial cost that has to be recovered from SA and NSW customers.
Reply to  RickWill
July 18, 2021 8:30 pm

I’m doing ok but I hate it; stupid people asking for it suffer; people on low income or pensions who can’t afford it suffer; politicians love it.

Reply to  Lrp
July 18, 2021 9:50 pm

I have seen people who advocate for low income groups actively supporting “renewable” energy. They have been duped into believing that fossil fuelled generators do not want the competition and that WDGs provide lower cost electricity.

Reply to  RickWill
July 19, 2021 4:08 am

Housetop are doing OK because they are heavily subsidized.

Tombstone Gabby
Reply to  Robber
July 18, 2021 9:00 pm

G’Day Robber,

“…30 minute spot prices vary…”

I visit:

on a daily basis. From that page you can access “Fuel Mix” and “Price and Demand”. On the P&D page, change the timing from 30 minutes to 5 minutes. Now you can see some real pricing spikes.

Andy Pattullo
July 18, 2021 2:39 pm

In the minds of zealots solar power and real economics exist in different universes. While facts and history show why solar cannot be a large part of a reliable affordable electricity supply, believers till think it is free energy for everyone all day.

Reply to  Andy Pattullo
July 18, 2021 4:50 pm

As far as I can tell, the law of supply and demand is extremely reliable. Marxists seem to have other theories.

You have to be really well educated to be able to ignore something as simple and reliable as the law of supply and demand.

Reply to  commieBob
July 19, 2021 12:25 am

Marxists are so utterly idiotic they can’t distinguish between value and cost (Cf: The Labour Theory of Value).

James Snook
July 18, 2021 2:44 pm

No surprise. The problem became apparent in Germany a couple of years back.

Installers naturally want to aligned panels to capture max sunshine intensity, resulting in them all peaking at the same time. The German Government was trying to get them to align the panels, not to maximise their output, but to capture the sun lower in the sky in the early evening and early morning. Don’t know how they went about it, or if they have succeeded. Installers certainly wouldnt do it unless they are compensated with hard cash.

Reply to  James Snook
July 18, 2021 6:46 pm

Western Australia has the issue

In 2019 it was problem of grid stability

By late 2020 we were paying companies to use the power AKA negative pricing

We simply have nowhere to dump the excess energy.

Reply to  James Snook
July 19, 2021 4:11 am

If they were being compensated based on what the electricity was actually worth instead of a fixed rate per MW/hr, then they would do it on their own.

July 18, 2021 2:51 pm

“But it needs to still get a whole lot cheaper.” What is that going to fix, its problem it over produces when it not needed and produce zip, when its need most. It is a toy for the rich that has duped the poor to pay for it. Just like EVs!

Tom Halla
July 18, 2021 2:55 pm

There are also the distortions wind and solar cause in the electricity market. As the non-dispatchables are not charged for the needed conventional backup, the owners of said backup have difficulty making a profit.
That sort of thing was partly responsible for the February Texas blackouts.

David A
Reply to  Tom Halla
July 18, 2021 9:32 pm

Yes indeed, solar and wind greatly increase the cost of dispatchables like coal and natural gas. ( greatly reduced revenue. Increased labor, that must be ready, but may not be needed, hard on equipment. )

These excess costs should be subtracted from the cost of coal and NG, and added to the cost of wind and solar.

July 18, 2021 2:57 pm

Oh dear! ‘Ow sad. Never mind.

Shoki Kaneda
July 18, 2021 2:58 pm

But it presents troubling implications for the world’s hopes of rapidly expanding solar capacity and meeting climate goals.”

It is not the world’s hopes. It is the dictate of a small group of delusional elites.

Rud Istvan
July 18, 2021 3:00 pm

Been obvious for years. The CA solar pricing/return dilemma is a direct result of the California ‘duck curve’, which has worsened every year for over a decade. Not something that more regulation or bigger subsidies can fix. And SoCalifornia is near ‘ideal’ for solar: mostly sunny, with peak loads summer afternoons… If it doesn’t work there, it doesn’t work anywhere.

A little renewable penetration into a dispatchable grid is manageable. A lot isn’t.
Greens want more than lots.

July 18, 2021 3:05 pm

Interesting. So Zeke Hausfather has branched out from Berkeley Earth and into this organisation who have written this report on solar

Zeke Hausfather | The Breakthrough Institute

joe belford
Reply to  tonyb
July 18, 2021 4:48 pm

Tonyb makes a 100% ad hominem comment.

Rud Istvan
Reply to  joe belford
July 18, 2021 5:33 pm

Joe, not 100%. Literally, ad hominem means ‘about the person’ in Latin. But in modern English, it means a personal aspertion—like Mann calling Curry a denier. Tony referenced Zeke, but did not disparage him at all.
Not even a nice try. You lose this round.

joe belford
Reply to  Rud Istvan
July 18, 2021 6:39 pm

Then take your pick Mr. Istvan, 99.9% or you have achieved a swing and a miss.

I claim 100% literal.

joe belford
Reply to  joe belford
July 18, 2021 6:46 pm

If you disagree with me Mr. Istvan, can you please point out the specific assertion Zeke makes that you disagree with regarding solar power growth?

joe belford
Reply to  joe belford
July 18, 2021 6:54 pm

Now Mr. Istvan, if I spoke about your reputation in the scientific community with respect to your presence on both this blog and Curry’s, at the web site, would you consider that to be an ad-hominem attack?

joe belford
Reply to  joe belford
July 18, 2021 7:14 pm

Mr. Istvan, Zeke has contributed to science with his name appearing on a lot of papers. How about you?

joe belford
Reply to  joe belford
July 18, 2021 7:16 pm

I guess all you are interested in is selling your e-books to the dweebs.

David Joseph Turell
Reply to  Charles Rotter
July 18, 2021 8:19 pm

“tonyb” is a mod, and he made the original ad-hominem comment

(Please no more discussion about Ad-Hominem statement, it is noted and dismissed) SUNMOD

Clyde Spencer
Reply to  joe belford
July 18, 2021 8:29 pm

Now that is an ad hom!

Clyde Spencer
Reply to  joe belford
July 18, 2021 8:34 pm

belford, you are out to lunch! That is not an ad hom on my part because it is simply a judgement of your behavior and has nothing to do with any scientific hypothesis that needs review.

Reply to  joe belford
July 18, 2021 9:46 pm

Methinks joe belford doth protest too much…

Reply to  joe belford
July 19, 2021 4:14 am

Joe reminds me of a 5 year old, constantly repeating himself in a desperate attempt to get the attention of the adults.
And yes joe, that was an ad hominem.
On the other hand, you haven’t actually made an argument to respond to yet.

Reply to  joe belford
July 18, 2021 5:55 pm

Not really.

But Hausfather and associates at Breakthrough at least had the backbone to publicly call out Michael Mann for publishing bullshit about their organization

joe belford
Reply to  Mr.
July 18, 2021 6:42 pm

Whataboutism doesn’t count, the post is 100% ad-hominem.

pHil R
Reply to  joe belford
July 18, 2021 7:42 pm

Jeebus, finish your drink and go sleep it off.

Reply to  joe belford
July 18, 2021 8:39 pm

I claim 100% literal.

So whats your problem then? The link goes to an about page.

In other news, the sky is blue and water is wet. 100% literal. Does this provoke you into replying to yourself too?

Reply to  joe belford
July 18, 2021 8:44 pm

I think we got your claim by about the 10th post … RAGE ON SON.

Reply to  joe belford
July 19, 2021 4:16 am

joe is like a child that has learned a new word, he has to use it everywhere. To bad he only knows the word, and not what it means.

Reply to  Mr.
July 19, 2021 6:07 am

And did Mann respond? Not likely. Interesting that BTI points out the poor quality of Mann’s research into their funding, matching his poor quality research into climate change…

Reply to  joe belford
July 18, 2021 8:33 pm

Oh no, you misunderstand the issue, which is why should someone profit from the consequences of his crimes.

Reply to  joe belford
July 19, 2021 4:13 am

So we can add ad hominem to the list of terms that joe uses but doesn’t understand.

Reply to  MarkW
July 19, 2021 12:16 pm

Well, you can’t expect him to understand ad hominem — he doesn’t even understand how to add.

Rich Davis
Reply to  beng135
July 19, 2021 5:58 pm

Two plus to plus too

Add homonyms


Rich Davis
July 18, 2021 3:15 pm

They’re talking about California here. How do the economics look in Seattle or Dublin? We had to spend trillions on an experiment to figure this out?

How about Glasgow in November? It would be great if COP26 had to rely 100% on wind and solar. When the time comes, we need to keep track of what % of Glasgow demand is supplied by wind and solar. It should be instructive.

July 18, 2021 4:26 pm

In Australian suburban streets, it has become common to see street lighting gradually evolving to solar power. Particularly noticeable is the use of temporary lighting units that have a heavy base and a substantial solar panel with high output LED flood lights. These overcome the need for noisy generators or temporary cables in construction zones.

The interesting aspect for the permanent street light installations is that the panels are mounted to optimise winter sunlight. In Melbourne the panels are angled at about 55 degrees to horizontal.

The only way grid scale solar generators can get any return in Australia is to install tracking panels. These will produce good output from sunrise to sunset and maximum power from 9am to 3pm. They inevitably throttle back through the middle of the day as rooftops start pumping out power.

This shows how the solid yellow grid scale solar backs off as the rooftops kick in (the yellow curve):
This is for Queensland during the balmy winter days when there is no need to run air-conditioners to cool houses.

Reply to  RickWill
July 19, 2021 5:26 am

There is no way tracking is ever economical. In addition to the extra cost of the tracking motor and more expensive mounts, in order to prevent the panels from shading each other in morning and evening, the panels have to be mounted much further apart.

Reply to  RickWill
July 19, 2021 12:53 pm

I have pointed this out before, there are limited specific applications where solar is a good idea. I like the stand-alone solar powered street light, it allows lighting in places that could use it but won’t get it because of the prohibitive cost of running a brand new power line that far. Think rest stops on remote rural highways, that currently address the problem by simply closing at nightfall. That’s all they power, though, you’re not going to run a water well or anything like that off those little bitty battery packs (they only work at all because they combine with LED lights).

michael hart
July 18, 2021 5:20 pm

So, duhhh…, you can’t cheaply store the excess energy generated from peak solar or wind.

It’s not like people on this blog and elsewhere haven’t been saying this for decades now.

Even Mosher’s protégé should be well aware of that.

Rud Istvan
Reply to  michael hart
July 18, 2021 5:34 pm

Uh, it’s not that you cannot cheaply store excess renewable energy. It’s that you cannot store it in grid quantity at all. Period.

Reply to  Rud Istvan
July 18, 2021 6:52 pm

Well, now, you can store it at grid scale, Rud – pumped hydro. At ruinous efficiency and exorbitant cost, but it it is possible.

Reply to  Writing Observer
July 18, 2021 7:54 pm

Only WHERE there is suitable grad and storage locations. Try it in most of the plains in the US.

And then get the permits approved anywhere in the US.

Reply to  Writing Observer
July 18, 2021 8:38 pm

Not everywhere; the best of pumped hydro sites are taken already, and new schemes are opposed by greens/environmentalists

July 18, 2021 6:34 pm

The final sentence in the article points to a solution.

“The Breakthrough study estimates that the value of solar–or the wholesale average price relative to other sources–will fall by 85% at that point, decimating the economics of solar farms, at least as California’s grid exists today.”

An electricity loss of 3.5% over 1,000 km for a UHVDC line, or about 10% for a 3,000 km line, is not too bad. The following Wiki article addresses the issue and problems.

“A long-distance, point-to-point HVDC transmission scheme generally has lower overall investment cost and lower losses than an equivalent AC transmission scheme. HVDC conversion equipment at the terminal stations is costly, but the total DC transmission-line costs over long distances are lower than for an AC line of the same distance. HVDC requires less conductor per unit distance than an AC line, as there is no need to support three phases and there is no skin effect.

Depending on voltage level and construction details, HVDC transmission losses are quoted at 3.5% per 1,000 km, about 50% less than AC (6.5%) lines at the same voltage. This is because direct current transfers only active power and thus causes lower losses than alternating current, which transfers both active and reactive power.”

However, as technology progresses, the world might eventually transition from the current AC system to a DC system, which could be far more efficient. Will it always be necessary to convert DC to AC, then back again to DC, when most appliances already use DC?

Dave Fair
Reply to  Vincent
July 18, 2021 9:50 pm

HVDC is used for bulk electricity transport from one point to another. HVAC is used as backbone power delivery throughout the various service areas because it can be stepped up and down in voltage level as needed.

Reply to  Vincent
July 18, 2021 10:40 pm

Putting aside the possibility of a future DC economy, if the transmission loss is less for DC than for AC, there is still a conversion loss from DC to AC. In small power supplies that can be double digit percentages. Without factoring that into the calculations there is no information about whether AC of DC from the grid is more efficient.

Joel O'Bryan
Reply to  Vincent
July 18, 2021 10:49 pm

You have no concept of grid stability and grid inertia (which stabilizes freq and volts) in an AC grid. DC to AC inversion provides nothing in terms of frequency stability.

Reply to  Joel O'Bryan
July 19, 2021 2:43 am

I agree that the subject of electricity distribution is not my field of expertise, but I do have concepts, and I do use my nous to determine what makes sense, and my sense of logic, rationality and common sense is quite good.

From that awful publication, Scientific American:

“In the late 19th century, two competing electricity systems jostled for dominance in electric power distribution in the United States and much of the industrialized world. Alternating current (AC) and direct current (DC) were both used to power devices like motors and light bulbs, but they were not interchangeable.

The rivalry was fraught with acrimony and publicity stunts — like Edison electrocuting an elephant to show AC was dangerous — but AC eventually won out as the standard for transmission, reigning for more than a century.”

Reply to  Vincent
July 19, 2021 5:32 am

AC won out not because of publicity stunts but because it was the better technology.
Because AC was easy to step up or down in voltage, it could be transmitted more efficiently.
DC transmission was limited to just a few miles from the power station.
At the time, conversion from AC to DC and back again was not practical for the purposes of line transmission.

You can use your “nous” all you want, but if you lack the basic facts, than your “nous” will always come up with the wrong answer.

Jim Gorman
Reply to  Vincent
July 19, 2021 5:53 am

This article has so many glaring problems it is sad it was published. Some problems never addressed.

  1. Power requirements and distribution wire size. DC is not amenable to voltage conversion. Higher voltages reduce current in wire thereby minimizing I^2R losses. With AC these voltages can easily be stepped down at local sites. DC requires inverters to change from DC to AC and back to DC again in order to convert voltages. Otherwise DC transmission lines must carry the full current at low voltages which maximizes any I^2R losses.
  2. It is impossible to have different voltages distributed to various users that are closely located without using different distribution lines or using costly inverters to change the voltages to what is needed. For instance, residential housing located around businesses.
  3. Most computer equipment uses 12v DC. Do you know why? Batteries were originally a nominal 12v DC. Ask yourself what voltage should be the common DC voltage in a new world. 5v DC? 3v DC? 24v DC? 48v DC? Could various different usages best work at different voltages? For example, heavy equipment vs laptops vs server farms. Are you going to simply move inefficiencies from changing AC to DC to the electronics needed to first invert DC to AC and back again in order to have various voltages for different uses?
  4. The heat generated at server farms comes less from the power supply equipment to converting from AC to DC than from the heat generated by the servers themselves operating with semiconductors. Why do you think CPU’s require massive heat sinks? How about laptops needing better CPU’s that generate less and less heat (better battery life)?

I could go on, but you get the picture. There is more to the issue than this referenced article provides. Kind of like climate science being explained by reporters with no technical background.

Reply to  Jim Gorman
July 19, 2021 12:25 pm

As to number three, I have several problems with that claim.
Lead acid batteries were usually 12V, however I have never seen a lead acid battery hooked up to a computer.

For portable electronics, ‘C’ and ‘D’ cells were the original power sources for electronics, and those things were around 1.5V each. Putting several in series in order to get higher voltages.
The and ‘AA’ and ‘AAA’ didn’t start to become popular until more recently. I’ve never seen a ‘B’ cell, but I did locate a picture of one once.

The small square batteries were 9V, and the big square “Lantern” batteries were 6V.

Most TTL logic, which was what most of the early computers were built using, required a 5V supply. When CMOS started coming out, those usually required 12V, but not because of any battery requirements.

Jim Gorman
Reply to  MarkW
July 19, 2021 7:26 pm

As to number three, I have several problems with that claim.

Lead acid batteries were usually 12V, however I have never seen a lead acid battery hooked up to a computer.

It is all the technology surrounding lead acid batteries and their use in auto’s, UPS’s, etc. Even early TTL logic used 5v but that was usually derived from a 12v rail by using regulators and pass transistors.

Are you familiar with a constant use 20 amp linear power supply? They are boat anchors. Using less voltage requires more current with an increase in wire size, meaning heavier transformers and power supply.

Reply to  Jim Gorman
July 19, 2021 7:50 pm

“I could go on, but you get the picture. There is more to the issue than this referenced article provides. Kind of like climate science being explained by reporters with no technical background.”

Yes, I do get the picture. However, in most situations there are usually both positive and negative aspects. As technology changes and advances, new possibilities arise. This is the amazing aspect of scientific progress.

The following Norwegian Thesis (for a Master of Science degree) presents an overview of the problems, advantages and disadvantages of both systems in our modern era. The English translation has rather poor grammar, so I’ve made some grammatical corrections in the quoted abstract of the thesis.

“The war between AC and DC has emerged once again due to the rapid development and advancement of electric power technologies. Nowadays, power electronics and DC/DC converters are able to change voltage levels, which could only be achieved by an AC transformer a hundred years ago. Rising trends in the development of electric vehicles and renewable energy technology have led to an urgency for a re-evaluation of which scheme between AC and DC will provide the best solution in terms of the economic and technical aspects. 

The flexibility that has been offered by the AC grid has made the AC grid become more favourable since late 19th century. However, the urge in using renewable energies due to environmental issues and concerns, has also initiated a second state of war between AC and DC. Hence, the re-evaluation of the usage of AC grid distribution in consideration of DC grid distribution. 

This project investigates the recent development of DC grid technology, compares AC and DC grids in low voltage distribution system, and evaluates the possibility of transition between HVAC grids into low voltage DC grid.”

Reply to  Vincent
July 19, 2021 12:22 pm

What does HVDC transmission (whether it’s good or not) have to do w/unreliable, intermittent, weather/time-of-day-dependent electric sources?

July 18, 2021 8:21 pm

Consumer electrical prices in California are regulated by the Public Utility Commission, not by market pricing. The rates are established far in advance of delivery. They have never gone down which is why California utility rates are the highest in the nation.

Reply to  Doonman
July 19, 2021 5:33 am

The article does not talk about consumer prices, it is talking about wholesale prices.

Joel O'Bryan
July 18, 2021 9:45 pm

Imagine having a near purely solar powered automobile. Maybe it has just a small battery or capacitor to get you through tunnels or under bridges but then back in the sunlight to keep going on Sunny days. You check the weather forecasts frequently to know when you can make your errands and get home. You dpend on the Wx forecasts being right. And when its cloudy all day you are forced to take the public transportation, which takes 2x-3x longer time out of your day.

But… your solar powered car only runs when the Sun is shining on its solar panels to make the wheels go round.

In the big picture, It has negative utility. That is, it frequently leaves you stranded when the clouds roll in unexpectedly and solar panels cannot produce the electricity juice needed to get you home.

Worse than useless, it is anti-useful. It frequently cost you far more than any emissions of pocket book savings you thought it might deliver.

Solar grid electricity is no different than that solar powered car. It has negative utility and will frequently leave you stranded with a very expensive work around when the Sun unexpectedly fails to shine per some Wx forecast.

Larry in Texas
Reply to  Joel O'Bryan
July 19, 2021 3:58 am

The concept of “negative utility” was rather dramatically demonstrated in Texas in February, when some of us were stranded without power because solar panels (and wind turbines, of which Texas has far more of) couldn’t work in the snow, cold, and dark of a bad winter storm.

Rod Gill
July 18, 2021 11:12 pm

This will happen for wind as well, but less dramatically. I’ve been on or around the sea most of my life (don’t ask how long but its many decades) I know that the wind dies as the sun goes down, unless there is a weather system blowing through.

That probably means that a low % of capacity is available at peak times in the evening and an increasing surplus during the day.

July 19, 2021 1:01 am

What happens in Californian on a calm sunny day when nearly all the generation is solar? Who is responsible for frequency control?

Willem Post
Reply to  Capell
July 19, 2021 11:00 am

Import it from China, just like the solar panels

Reply to  Capell
July 19, 2021 12:37 pm

Temp employees w/fast (60 Hz) fingers on a switch. Constantly fed Black-powder coffee & Zap cola.

July 19, 2021 2:55 am

A couple of years ago I was in a car park in South Wales, (Old South Wales) and the ticket machine, solar powered, wasn’t working. Just then a council van turned up with a newly charged battery from the Council depot. Turns out there isn’t enough sun in winter in Wales, to keep the machines fully charged, so a man with a van has to go and swap batteries for re-charging back at base. How proud those local councillors must be that they have invested in such a wonderful emission free system. (Don’t count the time and the fuel, just look at the solar panel on that machine).

July 19, 2021 3:03 am

People will just up the use of battery storage, or use it for hydrogen generation.

Reply to  griff
July 19, 2021 3:25 am

In your mind perhaps, but nowhere else.

David A
Reply to  griff
July 19, 2021 5:00 am

Easy peasy eh griff?
Please send me 10 k every decade for my battery storage. And pay for my battery disposal. So we have about $120.00 a month for storage, plus about $60.00 a month for solar panels. Plus about $25.0O monthly for grid connection.

And we then have a national problem of millions of panels and old batteries being waste every month.

Whereas NG, clean coal, and hydro, all operating without the handicap of playing second fiddle to wind and solar, could be producing and delivering the same energy for under $100.00 per month, with relatively zero waste disposal.

And crops would grow a bit faster, and save water and land, and have fractionally less frost damage at night.

And third and fourth generation nuclear would slowly come on line over the next century.

The economy would do well and there would be plenty of funding to take care of all real environmental issues. As populations naturally decrease so would the busybody population of political bureaucracy pundits.

Reply to  David A
July 19, 2021 12:27 pm

griff’s the idea guy, implementing his ideas is the job of the little people.

Reply to  griff
July 19, 2021 5:36 am

You assume that they will be able to afford more batteries. Hydrogen generation? Just how delusional can you get.

Rich Davis
Reply to  MarkW
July 19, 2021 6:18 pm

Pretty delusional indeed. Fields full of unicorns riding rainbows delusional. That’s our griff.

Rich Lambert
July 19, 2021 5:49 am

The article says, “Simply put: the more solar you add to the grid, the less valuable it becomes.” It would be more accurate to say, “the more expensive it becomes.”

Reply to  Rich Lambert
July 19, 2021 1:23 pm

You are confusing/conflating value and cost. Have you never heard of the foolish old miser, shunned by his family and friends because he knows “…the cost of everything, and the value of nothing…”? With renewables take everything you spent on the system, including all required backups, amortize that over the total energy the system will produce in its lifetime (that’s fixed cost), add to that the maintenance and other inputs needed to produce each kWh (that’s the variable costs) and that’s the “cost” of energy out of that system. Then, go to the spot-market and put that same energy up for sale, for use only when it can be produced, and that’s where you get the negative bids, users saying unequivocally, you would have to pay me to take that power off your hands, and that’s the “value” of it. Notice how the two numbers can be diametrically opposed.

What’s happening in real life, the unreliables are not accounting for their required backup, they’re making that someone else’s problem. But they have to have backup so many fossil fuel powered generators remain on-line and running but producing 0 power. Then the damn bureaucrats screw them again by converting their costs to Levelized Cost of Electricity (LOE). They’re still running, so that’s using up life of the equipment, but they’re only getting paid for the power they produce, so they have to charge more and more per kWh just to keep the machinery running. That’s why the overall cost of electricity RISES as the unreliables market penetration increases. If subsidies ended, we could go back to cheap electricity like we enjoyed in the 1980’s. In fact it would probably be even cheaper now because of the low natural gas prices.

Thomas Gasloli
July 19, 2021 6:31 am

In Michigan (only the Seattle area has less sun), Consumers Energy is proposing to shutdown fossil fuel fired generation and replace it with solar. They, of course, did not use historic weather data for their model, because that would have shown the idea is preposterous. They want the solar not because it will work, but, because it will give them a good rating on Wall Street where all the “smart” people have totally lost contact with reality.

Rich Lentz
July 19, 2021 7:32 am


willem post
July 19, 2021 8:44 am

Many categories of cost are not directly attributed to solar, such as managing DUCK CURVES with other generators and batteries.

Here is an excerpt of an article
Click on the URLs for full revelations.


Solar systems have their highest electricity production at midday.
The surge of production from near-zero to maximum causes disturbances on the grid, aka DUCK-curves.
Southern California and Southern Germany, with high MW of installed solar, have major DUCK-curves on sunny days.
At present, mostly gas-fired, combined-cycle gas-turbine (CCGT) power plants are used to counteract the DUCK-curve surges. 

In California, the shutdowns of 15 of 19 coastal, CCGT plants led to rolling blackouts during a multi-day heat wave covering a large area of the US southwest, followed by forest fires. 

Climate fighters want to shut down the CCGT plants and replace them with utility-scale battery systems.
Climate fighters accused the plants of heating the Pacific Ocean!

NOTE: In case of Germany:

– Whenever it has excess wind and solar electricity (which has high, subsidized costs/kWh), it usually spreads the excess into grids of nearby countries at very low, even negative, wholesale prices (excess supply lowers the price). 

– Whenever Germany has very little wind and solar electricity, these countries sell to Germany at higher wholesale prices (shortages increase prices). That procedure avoids having utility-scale battery systems, which would be off-the-charts more expensive, as shown in this article.

Solar Electricity Production and Midday Duck Curves

The image is of electricity demand, MW, versus time of day, due to various levels of installed MW DC of solar systems producing electricity, mostly at midday. Solar dozes off in late-afternoon/early-evening, when peak electricity demands occur, and does not reappear until about mid-morning the next day.

Planning Engineer
July 19, 2021 9:01 am

The article starts out: “A few lonely academics have been warning for years that solar power faces a fundamental challenge that could halt the industry’s breakneck growth. Simply put: the more solar you add to the grid, the less valuable it becomes.”

How about noting that anyone with half a brain working in the power supply/grid arena has known this for going on at least a couple decades.Many have tried to communicate this fundamental understanding to regulators, politicians and some headstrong ACADEMICS with considerable frustration. Amazing!

Reply to  Planning Engineer
July 19, 2021 12:45 pm

Engineering consistantly follows well-established (& usually hard-earned) rules. But people can go completely off the rails…

July 19, 2021 10:49 am

You know, it would be nice to define all the CAP abbreviations in one place. Not all of us are totally familiar with them.

Reply to  Philo
July 19, 2021 12:29 pm

Under the “REFERENCE PAGES” tab, there is an entry “GLOSSARY”, this contains a lot of acronyms. If the one you are concerned with isn’t there, you can request one of the moderators add it for you.

July 19, 2021 11:42 am

The plunging price of solar is of no benefit to consumers because the cost of trying to maintain a reliable grid needs non renewable back up provided by fossil fuels ( or giant batteries). Take away all subsidies and see who wins is the only way you will truly find out whether renewables can provide a cheap and reliable service.

July 19, 2021 4:19 pm

The last thing I want on my roof is a solar panel array.
Lots of my neighbors bought them, but when I do the math; it is so much cheaper to buy the power from the utility.

David A
Reply to  Roger
July 19, 2021 11:44 pm

It is certainly a variable on where you live for the solar production and the utility electricity cost, and how the utility charges for any delivered power solar fails to provide. ( And if course the federal and local subsidies)

July 24, 2021 3:02 pm

So build storage.

At no cost of course. :-o)

(Batteries, reservoirs to pump water up to then draw down through turbine generators, giant bag lakes, etc.
I’m not joking – someone proposed that for Lake Ontario.)

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