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Mon Jul 1, 2019, 06:01 PM

Nature (News): The Reality Behind Perovskite Solar Cells.

The news item I'll discuss in this post comes from one of the world's most prominent scientific journals Nature. I believe it's open sourced. It's this one: The reality behind solar power’s next star material (Nature 570, 429-432 (2019))

Some excerpts:

The Henn na hotel in Nagasaki, Japan, is not shy of trialling futuristic technology. It claimed to be the world’s first robot-staffed hotel in 2015 — but cut down on the automation after its robotic concierges frustrated some customers and didn’t reduce costs. Now, the Henn na is testing another attention-grabbing innovation: since December, its sign has been powered by a curved wall of prototype solar cells installed in the hotel’s grounds. Made by Polish start-up firm Saule Technologies, the cells exploit micrometre-thin films made from materials called perovskites, which in just a decade have shot from laboratory curiosity to bright new prospect for solar power...

...More than a dozen companies worldwide (see ‘Solar hopes’), a mixture of established electronics giants and start-ups, are hoping soon to sell panels made with perovskites. Dozens more are involved in making materials for the products, says Margareth Gagliardi, an analyst with BCC Research in Wellesley, Massachusetts.

For decades, slabs of crystalline silicon have dominated the solar industry. Other materials that can be layered in thin films, such as copper indium gallium selenide (CIGS) and cadmium telluride (CdTe), have captured less than 5% of the market, because it’s hard to make them as efficient or cheap as conventional solar panels. Perovskites could be a different story. They should be cheaper to make and seem impressively efficient at converting sunlight into electricity — in the laboratory, at least.

Wow. For decades...

Often over the last ten years since I went from enthusiasm for the solar industry to hostility, as I've remarked on the failure of the solar industry to do anything to address climate change after half a century of wild cheering for it, one of the more common explanations (excuses?) is that it's a "new industry."

It's a "new industry" that has soaked up over a trillion dollars (with another more than a trillion on wind) in the last ten years.

Frankfurt School/UNEP Global Renewable Energy Investment, 2018, Figure 3, page 14

Further excerpts:

Not even the technology’s keenest advocates think that perovskite cells will quickly displace silicon, however. Instead, some firms are layering low-cost perovskite crystals on top of silicon to make ‘tandem’ devices that convert more of the Sun’s energy than either material alone. Oxford PV, for instance, intends to make tandems this year that it says will be one-fifth more efficient than top-end commercial solar panels. If rolled out across the industry, the total power output of solar panels made annually would leap by that same proportion...


I can't say how many "ifs" I have heard about solar energy since 1970 (when I was a kid), soon to be 50 years ago.

...But there are still fundamental questions to answer about the new materials. It’s not clear whether perovskites will be durable enough to work through rain, wind, intense sunshine and freezing temperatures for the 25 years that silicon panels promise. Most perovskite devices contain lead, raising concerns about toxicity, and researchers are not convinced that efficiency records in the lab will translate to the commercial scale. Meanwhile, conventional solar panels have been getting ever cheaper and more efficient. That makes it hard for a new material to outperform them and accelerate efforts to combat climate change. “I wouldn’t put all my eggs in this basket for solving the world’s problems, but I also wouldn’t rule it out,” says Sarah Kurtz, a photovoltaics expert at the University of California, Merced...

Actually we have put all of our "eggs in one basket" in addressing - or put more properly pretending to address climate change: So called "renewable energy."

I note, with tremendous sadness at the edification of fear and ignorance, that many of the people who have bet the planetary atmosphere on so called "renewable energy" are more opposed to nuclear energy than to dangerous fossil fuels, even though dangerous fossil fuel waste, along with biomass combustion waste is responsible for 7 million deaths per year, and so called "nuclear waste," um, isn't.

Here is the most recent full report from the Global Burden of Disease Report, a survey of all causes of death and disability from environmental and lifestyle risks: Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015 (Lancet 2016; 388: 1659–724) One can easily locate in this open sourced document compiled by an international consortium of medical and scientific professionals how many people die from causes related to air pollution, particulates, ozone, etc.

The note about lead being in these solar cells of course doesn't matter, or course, anymore than cadmium or tellurium mattered since no amount of toxic material being distributed by the solar industry can matter since solar cells are always "green," as we often hear in all kinds of advertisements about being "green."

Except they aren't. The last major distributed energy scheme involving lead was tetraethyl lead in gasoline, in the world's most successful "distributed energy" technology, the automobile. Up until the present day, whenever the chaparral in California blazes, some of that historically deposited lead is volatilized.

Now we want to distribute more lead. Good idea!

A picture from the article.

One may also question how "renewable" cesium is, and for that matter, iodine, but no matter...

No matter...

No matter...


Will they last?

The major challenge for perovskites, however, is whether they can last as long as silicon panels, which generally come with a 25-year warranty. Perovskite stability “needs to approach the norms established by silicon” and that is “now looking increasingly unlikely”, says Martin Green, who researches perovskites and other solar materials at the University of New South Wales in Sydney, Australia. His team collaborates on the materials with two large Chinese solar-panel makers, Trina Solar and Suntech...

...Perovskites are sensitive to air and moisture, but that shouldn’t be a killer problem. Commercial solar panels already encapsulate their photovoltaic materials in plastic and glass for protection...

...A deeper issue lies in the crystals themselves. In some cases, the structures shift as the perovskites warm up; the change is reversible, but it affects performance...

Ummmm... plastic...eating it is good for you, and be sure you are eating it, pretty much every damned day, a little more won't hurt you.

And the argument is made that a little more lead won't hurt you, since possibly lead based solar cells are even greener than silicon solar cells:

Lead toxicity

Another potential stumbling block for perovskite cells is that the best of them contain lead, a toxic metal. Researchers have tried alternatives, such as tin, but performance declines. That doesn’t mean the cells can’t be used. A life-cycle analysis of Oxford PV’s tandem cells suggests that the small amount of lead they contain wouldn’t have much impact on environmental toxicity if it leaked. The analysis also argues that silicon cells have a worse overall environmental impact because of the resources used in their production.

Whiny people disagree:

But some researchers say the inclusion of lead rules out the idea of using perovskites in disposable products. Grätzel thinks they might find a use in large solar farms where people seldom go. “If someone wants to sell flexible devices, they have the wrong idea,” he says. “What happens if a kid pierces the plastic cover? There is no compromise on lead toxicity.”

We can, of course, compromise on anything declared in the popular imagination, if not reality, to be "green."

The result of the bet of the planetary atmosphere on so called "renewable energy" has been reported by the International Energy Agency:

In this century, world energy demand grew by 164.83 exajoules to 584.95 exajoules.

In this century, world gas demand grew by 43.38 exajoules to 130.08 exajoules.

In this century, the use of petroleum grew by 32.03 exajoules to 185.68 exajoules.

In this century, the use of coal grew by 60.25 exajoules to 157.01 exajoules.

In this century, the solar, wind, geothermal, and tidal energy on which people so cheerfully have bet the entire planetary atmosphere, stealing the future from all future generations, grew by 8.12 exajoules to 10.63 exajoules.

10.63 exajoules is under 2% of the world energy demand.

2018 Edition of the World Energy Outlook Table 1.1 Page 38 (I have converted MTOE in the original table to the SI unit exajoules in this text.)

But the most telling result of this bet is written in the planetary atmosphere. From this week's data from the Mauna Loa Carbon Dioxide Observatory:

Up-to-date weekly average CO2 at Mauna Loa

Week beginning on June 23, 2019: 413.35 ppm
Weekly value from 1 year ago: 410.73 ppm
Weekly value from 10 years ago: 388.54 ppm
Last updated: July 1, 2019

If the fact that the carbon dioxide concentrations are 24.81 ppm higher than they were ten years ago troubles you, don't worry, be happy.

It's not your problem; it's a problem for babies, since it is they and not us, who will have to live up to all that "by 2030" and "by 2050" bullshit that they've been handing out at the anti-nuke ignorance squad at Greenpeace ever since 1970 when, of course, it was "by 2020," but no matter...

No matter...no matter...

Elon Musk. Tesla electric car. Plastic and steel wind turbines in the benthic ecosystem off New Jersey. Solar thermal. Solar house. Solar roof. Happy. Happy. Be happy. Be nice.

Don't worry...be happy...

No one now living, Bill McKibben and his Prius be damned, will ever see a reading at Mauna Loa of below 400 ppm of the dangerous fossil fuel waste carbon dioxide in the planetary atmosphere again.

History will not forgive us, nor should it.

Have a nice evening.

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