Saturday, April 21, 2018

Photovoltaics? Who in the world would want to spend money on such a silly idea?

The "Solar Roadways" plant in Idaho in an image from the "EmphaseEnergy" site. The performance of this expensive plant is abysmally low and, with the best of good will, I can't see it as anything but a propaganda stunt to denigrate renewable energy. Not the only example of this strategy.

I have to confess to you one of my darkest sins: I read the unnameable blog by Anthony Whatever "What's down with this" and, occasionally, I even enjoy it. Probably, this sin of mine is condemning me to Hell, where I will be punished by having to spend eternity trying to teach thermodynamics to an audience of neoclassical economists.

Sometimes, however, the unnameable blog is worth reading. For instance, in a recent post, Will Eschenbach engages in an all-out attack against the "solar roads" plant in Idaho. The post is appropriately titled, "The Road to Hell is Paved with Solar Panels" and, in it, Mr. Eschenbach criticizes the plant mainly in terms of the cost of the energy produced. He says that it produced 246 kWh in one year. Comparing with the total cost of the plant, said to be more than 4 million dollars, then, clearly, it is a bad deal.

Eschenbach has a point here, although, for fairness, we must note that the plant was never conceived as a commercial plant, it is a prototype or a demonstrator which involved a cost in terms of the development of special panels for a specific task. It is unfair to pretend from a prototype to generate a profit. The question is, rather, is the performance of the prototype good enough to be worth reproducing it at a commercial scale?

Clearly, the people of solar roadways have grand plans. In their site, they speak of paving all the roads in the 48 contiguous states and produce something like 15,847 Billion Kilowatt-hours per year, which is three times the total consumed today. There is a little problem, though: how efficiently could that be done? In their site, nowhere you can find the rated power and the actual performance of the prototype system. But, with some work, we can estimate these parameters.

First if all, they say that they installed 30 panels of 44 W each, The number is confirmed by counting the panels on the pictures of the plant (see on the right, from Google maps). So, that makes a total rated power of 1.3 kW. Then, the data at tell us that a zero-tilt, 1.3 kW fixed solar plant in Idaho is expected to produce about 1600 kWh/year.

Comparing this result with the 246 kWh reported by Eschenbach, we see that the plant has big problems: it produces less than 20% of what it should produce. There are various reasons that may explain the poor performance of a PV plant. In this case, it seems reasonable to me that a plant located in the middle of a parking lot - with people walking on it - produces much less than a standard plant would do.

So, Eschenbach is correct in noting the poor performance of the plant - nobody would ever want to use these devices for anything more than an expensive toy in a parking lot. But, in the end, that's not so much the point. The point is that the idea of "solar roadways" just makes no sense. Do you really want trucks to run over solar cells? I mean, think about that for two seconds and you can realize how silly the idea is.

This is not the only case I know of badly overpriced and poorly conceived solar plants. In the picture, here, you can see the "solar diamond," another high-cost PV installation built by ENEL in 2009 in Italy. (BTW, it stands close to where I live!)

Maybe you could find this object aesthetically pleasing, but the shape is wrong for a PV plant and its performance is abysmally low. You may also be interested to know that the cost of the whole plant, which includes a fancy hydrogen storage system, was about a million Euros for a total rated power of 13 kW. A better ratio of cost to power than the "solar road" in Idaho and, at least, this one is not supposed to have trucks running on it. But a big waste of money anyway.

So, how come that people engage in these silly ideas? Hard to say, there surely holds the principle that Eschenbach paraphrased in the title of his post "The road to hell is paved with good intentions." But, in addition to that, I can't avoid thinking that the people who promoted the idea and financed these plants did that with the specific idea to pass the message that PV is expensive and useless (*). As usual, propaganda rules the world.

(*) Note: this statement doesn't imply that the people behind the Idaho plant (Scott and Julie Brusaw) are evil or trolls paid by the fossil fuel industry. They may well be true believers in solar roads. Ufortunately, their work is being exploited by the enemies of renewable energy and they are helping to disparage the ideas that they try to promote. Propaganda is an opportunistic beast, extremely dangerous and always hungry.


  1. Ugo
    How about the idea that the 'real' cost of solar is batteries? I know people who maintain sets of lead batteries (fairly cheap) off-grid in sunny places and make careful audited use of solar power for all their useful machinery - everything from washing clothes to drying fruit to cutting wood - matching daily demand to available power. It is expensive.

    I rather like the idea of an electric hybrid pedal cycle, but, if my PC is a measure, the lithium battery deteriorates chemically from the day it is made, whatever the use. Given the yearly mileage for a cycle - used mostly for short journeys with utilitarian purpose - I am not getting a lot of mileage for the maintenance cost or for my contribution of sweat. You can enlighten us about the environmental constraints of another billion lithium batteries if these bikes become the next big thing.

    At the moment I use just my sweat to save motoring and with luck to prolong my active life.


  2. Ugo: Thanks for the link.

    Look, I am on your side on this, and reading WUWT should be required reading for anyone who want to consider themselves a "scientist".

    Now, before anyone becomes unglued and starts damning me to dystopian hell, you will note that I said "read" and not "take for truth" or "act upon this interpretation". I think that the most important thing that anyone who is trying to construct a valid hypothesis/theory/model/law is to look hard at data that doesn't fit.

    One of the most irritating things that I hear in the industry-disguising-itself-as-a-science (Western Medicine) is "The plural of anecdote is not data". What really pisses the MD's off is when you ask them "what is the relationship between anecdote and datum?"

    When you read sites like WUWT, you are looking at a finely oiled machine that is out searching for anecdotes that they feel "disproves" your theory. By paying attention, taking them seriously, and looking at the "outliers" that they present, you can improve the model. Isn't that the real purpose of science?

    I used to have a picture in my lab in the long ago, it showed a strip chart recorder on my GC/FID with the strip running straight from the strip chart recorder to a garbage can. It had printed on it the phrase "If the data doesn't fit the theory, the data must be discarded". I crafted this work of art after a particularly acrimonious meeting with the PI.

    1. Well said, Degringolade. The site by Anthony Watts is a mine of ideas, good and bad ones. Sometimes truly ugly when they practice the Serengeti strategy, but sometimes providing useful information. I have it in my feed.

    2. Tamino's site does a good job of taking some of Watt's sites obfuscations and explaining how they create that obfuscation. See here for a recent example

    3. See also the blog by "Sou from Bundanga" Great blog and great lady writing on it

  3. Dear Mr. Bardi,
    I have been reading your blog for years, and never expected to see you talk about my own backyard, here in the 'wilds' of North Idaho. I have interviewed the Brusaws a few times over the years as they have pursued the idea of solar roadways. They are true believers. Me, maybe not so much, but I honor their willingness to try to address the issues we face as a society instead of burying their heads in the sand. The demonstration set up in our town square has, I believe, been a series of failures, though I expect that is true of most prototypes. Yet many areas are experimenting with this idea ( why? I think it's because we already spend an enormous amount on our roads. Here in North Idaho, it seems that not long after a stretch of road is being built, it's being rebuilt again. It's tempting to try to recapture some of the investment by making the road work in our behalf. I personally don't buy in to the solar road idea as much (I think I might get more behind capturing kinetic energy from cars moving over a road but am not a scientist and have no idea how that could be done)but based on my interviews with the Brusaws, they are not propagandists working to denigrate PV.

    1. Thanks for this note, CCT, I suspected that the Brusaws were good people, unfortunately exploited by the forces of evil. You confirm this impression of mine. I added a note to the post, specifying that this post is not meant to disparage the Brusaws, nor to say that they are in the payroll of the fossil fuel industry.

      Too bad that in the real world evil wins most of the times! And, despite their good intentions, the Brusaws are taking a lot of flak from several sources - which I think is eventually the way the universe flows.

  4. The loss of efficiency of the road PVs vs the nrel calculator is easy to explain (the nrel panel did not need to be hardened against vehicle damage), but represents a best case (pedestrians don't leak oil). My guess is the road panel yield would go down quickly as the roadway ages.

  5. I can understand wanting to use PV modules in places that are already disturbed by development, but why not go with roofs first? They afford a reasonable amount of protection from damage, have better solar access and are more likely to remain clean than ground-level surfaces. After roof space is used up, start using PV as roofs/shade structures over parking lots and other spaces, then switch to unused brown-field sites. The last place anyone should put PV modules is on a road.

  6. Ugo, I can't believe people do stupid things just to prove how stupid they are. People do stupid things because they really believe they are not stupid. Just my opinion, but then I can't stand Anthony Watts!

  7. It looks like the Solar Roadways people are still at it.

    I became aware of them nearly a decade ago--which is an age in internet time--so I don't have links. Like the e-cat machine, it seems to be a scam. At the time they seemed to be based in Colorado.

    Back then, an Australian team posted a video taking the solar roadway concept apart from just about every angle. They did not neglect the problem of having trucks roll over these things, but they include a lot more besides--and included calculations in the video that were side-splittingly funny, a joy to behold. Engineering humor, to be sure, but really great--a full hour of fun.

    So why would anyone fall for this? People have no idea what is real and what is not.


  8. Ugo- the lesson here is that while environmentalists might have the best intentions for heading toward a better future, there is no central control, and people being people, many strike out on their own. Some are more inspired than science based, so there will be a certain amount of poor choices made. Checking the websites of those who disagree is a good corrective as you say, since some of their critique will be useful.

    A website I follow that is more useful than WUWT is Energy Matters. Its a hangout for past oil drum folks, with a decided slant toward nuclear. But their assessments of all sources of energy are pretty good discussion grist, pointing out the conceptual flaws in many "green" initiatives that really should be addressed. The comments section contributors have some really engineering expertise with citations of source documents being common.



Ugo Bardi is a member of the Club of Rome and the author of "Extracted: how the quest for mineral resources is plundering the Planet" (Chelsea Green 2014). His most recent book is "The Seneca Effect" (Springer 2017)