Monday, July 19, 2021

Why Solar Power Isn't Likely to Keep Getting More Common

Over the last few years, the industrial-scale prices on solar panel systems have come down, but solar energy and the so-called renewable energy sources are better thought of as intermittent energy sources.  Nobody can control how much time the sun shines (or the wind blows) and even the biggest photovoltaic installations are subject to weather issues. Because solar power is intermittent and not at the control of plant managers who can turn up the output when it's needed and turn it down when not needed, the power from these sources gets sold into the electricity market at the price when it's available.  The inexorable law of supply and demand says that if it's not needed, prices will plummet.  

It has happened already that solar power has gone negative in price; they have to pay the recipient to take it.  

This idea comes from a short, very readable post on Watts Up With That called "The lurking threat to solar power's growth."  The main sources are an article in MIT Technology Review and from a "Global Research Center" (Think Tank?) called the Breakthrough Institute.   As usual, I'll put some excerpts here.   

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.

This is already being felt in California.  Cali has among the world's highest percentages of power that come from solar, and they're feeling the pinch already.

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.

California gets about 19% of its energy from solar.  The next closest states are in the vicinity of 13% (Hawaii and Nevada).  Even at 19%, solar electricity is already being knocked down in price below where it's comfortable, a process known as solar value deflation. 

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.

The bottom line on this is that it appears the pace of adding solar power is going to slow down.  Sure, some combination of the current heavy solar subsidies and the rapidly declining cost of solar power can offset the falling value of solar energy.  As long as it gets ever cheaper to build and operate solar power plants, value deflation is less of a problem.    

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.

A solar farm in California's Death Valley.  Getty Images - from MIT Technology Review.

Think of what's going on with solar in California as a sneak preview of what's coming everywhere.


  1. Proposed solution: electrical transmission lines to other side of Earth, where the sun is shining. Your choice of going around or going through.

    1. Which is more expensive: power transmission lines from the opposite hemisphere and all the infrastructure that requires, or state-sized arrays of storage batteries and all the infrastructure that requires? Which has the worse environmental impact?

  2. Private solar for homeowners is a decent allows for peak use of electricity to be available for commercial needs while still making it possible
    for Suzy Homemaker to dry her laundry and run her AC on a hot afternoon.
    But until/unless science comes up with a feasible large scale method of storing
    electricity from solar and wind for use at night and on calm days these resources will always be unreliable niche resources that cannot be counted upon.

  3. Yeah... And we are seeing the same stupidity in Germany, where they are now cutting down whole forests for 'bio-fuel' in order to make up for the closing of so many conventional and nuclear powerplants.

    Seems the solar and wind farms aren't handling the load.


    1. Every time I hear some greenie talking about "renewables" my instinctive reaction is to remind them that petroleum and nuclear got us off renewables, because the means burning trees. Remember the story about how oil and gas saved the cities from being covered in horse shit? That's "renewables" technology.

      If we got rid of fossil fuels, there wouldn't be a tree left on earth within a year. Millions would die of starvation because food would never get distributed. Of course, for most of them killing of billions is a feature, not a bug.

  4. Im gonna have to disagree on this one. Personally I think grid tie (feeding back to grid, no local storage) is a losers game. Also there are other variables to consider besides $$$

    As a example in my blog comeandmakeit over the last few months I have documented extensively the financial aspect of my grid tie system (with battery storage, none sent back to the grid)

    With local power rates in the 20cents USD per kwh we are able to basically cut the power bill about 1/3 with 2200 watts of panels.

    It does not seem like a lot but there are other factors to consider. Namely that we no longer have blackouts. My system is set up so the inverter and battery is drawn down to 65% at the end of the night, but if there is a blackout, the battery will come on and the system functions as a whole house UPS.

    Another thing is the thing called grid defection. We have essentially defected from the grid from 8am to 8pm every day on average. If we had yet another week long typhoon power outage, we would still have plenty of power for lights fridge and fans. We would not have a/c

    So then the question is did we pay it forward, or did we ensure that we could get by without the grid? Did we lock in current rates so to speak by spending a couple grand on solar equipment and avoid potential inflation rate increases?


    1. I've been following your stories on solar.

      The one thing I'd point out is that this article isn't about home solar systems and tying back to the grid; this is about the power utilities. Cali has been giving incentives to the utilities to build out solar and they've been doing so. This is all utility-level stuff.

      About 10 or 12 years ago, I was considering solar for after the hurricanes. Most of the neighbors (by the sound of it) had the 1 to 5 kW gasoline powered generators, and had to run a steady supply line to the gas stations to keep the generators running. At the time, even with all the incentives (other people's money), a solar system was more than 10x the price of a big generator, run off the natural gas utility.

      There's an axiom about powering your home that you've probably run into: the cheapest watt is the one you don't use. You're doing all those decisions or calculations.

  5. Storage is pretty much the key issue here. (Well that and paving the entire land-area of the desert southwest in panels, if you're talking about seriously running civilization on solar.)

    The grid is a big capacitor (ish, some induction there too) - we're talking seconds of storage here, not days. If you want a serious solar plant, it needs to be built with massive battery banks that can store days (at least one day at bare minimum) of energy. Otherwise you're not serious, and natural-gas backing plants are going to be picking up the vast majority of the load.

    For fixed-installations there's no reason you couldn't use lead-acid to store power - weight isn't an issue. No need to go clawing at the few scraps of cobalt we can get out of war-torn Africa.

    When I lived in California, there were solar panels in Palmdale. Then way out in rural Mojave towns they hid what really held up the grid: The natural gas backing plants that would kick on every night.


  6. I'm actually contemplating doing a solar/battery system using the roof of my outbuilding. I calculate I could probably store enough for my house for a day with a few thousand dollars worth of batteries. My bank account won't support it though, so I'll start small playing with panels, inverters, and a few batteries.

    We might ease into having that sort of storage capacity over time if more people started building battery banks into houses. Both battery banks/solar and local generators would make civilization resilient against godawful incompetence and corruption wrecking the centralized infrastructure.


  7. I understand the thrust of the post was toward utility based solar, but just as with high end video card prices falling because hard core gamers drove the market I suspect the same is true with solar panels. A few years ago I looked into buying a couple 100 watt monocrystaline panels. At the time the price was about $150 each. The price today was $100. If you look at how well California is doing with keeping the lights on. Combined with the drought, the drawing down of reservoirs and how that is and will affect power generation in states that depend on hydro and one might think the feds might have eastern areas "shipping" power to keep their lights on at the potential expense of brownouts here. We all have to share the hardships don'tcha know. This has been the long way around to ask opinions regarding future solar panel prices and availability. If utility level solar becomes financially nonviable there are downstream effects. Do you drop 5-6 hundred on panels now to at least keep lights on(yeah,yeah I understand about batteries, charge controllers, inverters wires etc.)and maybe a couple luxuries. Or do you wait a bit to see if manufacturers start offering the 250 watt panels at the same prices(more or less)that the 100 watt ones are now so as to keep production lines running.

    1. Sorry - been out in the shop and not keeping up with comments.

      Short answer is I don't think there's much to gain in panels other than more production. A rule of thumb is if you double quantities, prices drop by about 25 to 30%. Doesn't sound like 250 Watt panels will be hitting that price without several doublings of the production amounts.

      Second thing to bear in mind is that solar cells, in real life use, are doing good to get more than 25 to 30% efficiency. That tells me that a 200 W panel pretty much has to be twice the area of a 100 W panel. I don't think they're going to double efficiency but maybe 30 to 35% - again, I'm not an expert in this field. (There are lab cells that get ~50% efficient, but once in the package in the field, they get degraded by dust, dirt, bird poop, pollen and everything in the real world).

      It would be great if someone who really knows the field would drop by and talk about this.

  8. Technology cannot change the laws of physics or thermodynamics or even the economy.
    The real solution is to use less enetgy.
    We can wean ourselves off in a controlled manner or be plunged into darkness and hardship overnight. Its OK to do work manually. Its OK to go outside to sit in the shade if its hot. Its OK to dry your clothes in the sun or not have a TV. Its OK to set your life up so you dont need a car and not that hard to do-especially if you dont have kids or are retired.
    Government and Business want to keep you addicted. They are fighting for survival also!

    1. Technology cannot change the laws of physics or thermodynamics or even the economy.
      The real solution is to use less energy.

      Either that or produce more. The answer there is clearly either more natural gas plants or nuclear. I read a review article the other day that said Fusion power is probably another 30 years away. I remember reading folks saying that 50 years ago.

    2. I could sort of talk/rant at length about fusion power, since I worked a bit in the field a while back. Not about our specific project (company secrecy/nondisclosure), but about fusion power in general. If there is any interest.

      A broad point: No technology is "X years away", so much as it is "X ideas away", or "X inventors working on the problem with appropriate tools away". Was the controlled fission chain reaction "42 years away" in 1900?


    3. PS: We're "addicted" to energy the same way you're "addicted" to oxygen. We need it to survive. We need it to drive the processes which keep food on the table. The problem with Greens is that they treat it as some optional thing, and we could all go back to agrarian animal-powered subsistence farming and everything would be bucolic and well with the world. All 7 billion of us, even though there are too few arable acres for that to even be a prospect.

      If Greens (of the hair-shirt sort) ever got their way, 9/10ths of humanity would die. They would die because their food couldn't be farmed (not at the scale and with the ease that gasoline-powered tractors allow), the soil couldn't be kept arable without artificial nitrogenation, and it couldn't be trucked into those hive-cities where they live trendy driverless lifestyles. Their water would stop flowing in areas where there are too many people to draw it from the local water table with muscle-powered pumps.

      Energy starvation is a serious civilization destroying prospect: One that sane people would do to fend off, and crazed ideologues are trying to force.


    4. I'd be delighted to run a good overview on fusion, the prospects and the problems. The article I was referring to is: here on WUWT. Its main point is that research has focused on the Tokamak concept for decades and that author thinks it has outlived its usefulness (my words, not his). I'm terribly underselling the piece so give it a read (if you haven't).

      As always, I can be reached as SiGraybeard via gmail.

    5. I just read the article. I do have some disagreements with it. I suppose I'll have to write something in reply. (May be a week though, I'm preparing for a work-related trip.)

      One point: He's right that the reaction all fusion research currently targets is the D+T reaction. There are a lot of low-atomic-mass fusion reactions:

      p+p, what powers main sequence stars, has a reaction cross section that is far too low at any temperature to build reactors of reasonable size. You might be surprised that the power density in the core of stars is something like sub-10 W/m^3. They get away with it by being enormous.

      D+D has a reaction cross section 100x lower than D+T.

      D+He3 is an interesting one, and it sort of bears on the point the author is making (in error, IMO).

      The point of fusion is that we'd have a nuclear energy source (powerful, controllable baseload plants) where we would never run out of fuel. Deuterium is present in sea-water, and we can filter it out from there in effectively infinite amounts.

      Tritium doesn't occur in nature. He makes a remark about "current supplies", but there are *no* supplies without some sort of source. We currently obtain tritium by bombarding Lithium-6 (Lithium with 3 neutrons instead of the usual 4) rods in a fast-neutron fission reactor. Tritium has a half-life of 12 years and beta-decays into Helium 3.

      Both D+T and D+He3 have comparable cross sections (at 100keV), so reactors of similar size and confinement ability could burn either fuel. We could get He3 by just letting tritium beta decay into He3.

      D+T yields a neutron, and D+He3 yields a proton with the reaction: But we need the neutron, because we need to breed more tritium. A viable fusion power plant would either have to have an independent source of He3, or neutrons from D+T to make more tritium. The neutrons must be caught by a blanket containing Li6 and a neutron multiplier (the papers I recall had lead-sulfide of some isotope). With that the cycle is closed and you don't need fission plants to supply the tritium.

      It's complicated, but it isn't a subterfuge. It's just what you have to do to attain the goal (a viable fuel cycle using stuff we can get from nature in huge amounts.)

      There are a few others that are interesting. p+B11 yields 3 alpha particles, no neutrons, plenty of energy. The problem with that one is that a p+B11 plasma radiates (via Bremstrahlung, which is sort of your best-case baseline scenario) faster than it produces power via fusion. Since plasmas at any of the densities we can generate are "optically thin" (light basically just leaves and hits a wall), that means you can't really get net energy out of the reaction without some clever way around that.

      As to tritium being "radioactive", yes technically (eyeroll), but it's a beta emitter. A sheet of tinfoil stops beta-rays. As long as you're not inhaling it, it's not harmful. (Perhaps this is why the popular science press doesn't dwell on tritium - because screaming luddites can't handle the thought of anything radioactive.)

      Neutron activation - you're going to get that in just about any nuclear device. The "radioactive waste", by which he means the reactor structure, is only mildly so and it's not difficult to store. The fuel throughput produces no radioactive end products.

      (Running long. If I finish something more organized I'll email.)


  9. Price only matters if you're selling through.

    What doesn't change are a couple of things, one tangible, and one intangible:

    1)The peak solar days are also the peak days of A/C demand. A building roof carpeted with solar panels is powering its own cooling, and using the sun to do it, not the grid. Any excess drives prices down for everyone else buying power, and de-loads the entire grid.

    2) The more locations with solar power and storage, the less grid problems even matter.
    * PG&E effs up and sets the state on fire, and then shuts down? You've got solar. Who cares?
    * There's another brownout? You've got solar. Being grid-tied is a third-world problem, not a first-world one.
    * There's an earthquake, or even total societal meltdown?
    BFD. You'll be running 24/7/365 on panels and stored battery power for the next quarter century. And blackout drapes mean no one's the wiser, but you're not going to be sweating into your sheets every August.

    Besides, the utility companies' crony capitalism in Califrutopia means that, by law, you have to ask the utility company's permission to go solar, and only something like 10% of the state can ever do so, to protect their energy monopoly.
    Yes, really..

    But if you build in BFE, from scratch, and never were part of the grid, and don't hook into it, that doesn't apply.

    So the push-pull drives smart people out into the hinterboonies, and leaves the sheeple in the blue hive cities stuck on the antiquated, under-maintained failing grid, and paying through the nose for the privilege of a refrigerator and A/C. Frequently, not both at the same time.

    Yet again, win-win.

    Go bullish on battery companies.
    SoCal Edison and PG&E, OTOH, are the world's next tobacco companies hereabouts.

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  11. only thing I know for sure - having a system that actually produces 5 kw and has a battery bank would be a comfort in the years ahead. solar isn't for vast energy farms and the grid. solar is for a country house on acreage.