We could recycle the world's most "efficient" solar cells when they fail, um, couldn't we? [View all]

[NNadir]

They are also the world's most toxic solar cells, but who cares? Solar energy, even if it has failed spectacularly even to slow the degradation of the planetary atmosphere is still, um, "green," right?

The following paper is found in the current issue of ACS Sustainable Chemistry and Engineering:

New Films on Old Substrates: Toward Green and Sustainable Energy Production via Recycling of Functional Components from Degraded Perovskite Solar Cells (ACS Sustainable Chem. Eng., 2017, 5 (4), pp 3261–3269)

Organic/Perovskite Solar Cells are latest among the tens of thousands of "solar breakthroughs" of which you have heard if lived long enough, at least as long as I have lived, which is a long time.

And the introduction to the linked paper tells you, almost breathlessly how "breakthroughy" they are:

Organic−inorganic hybrid lead halide perovskite solar cells(PSCs) have recently taken the photovoltaic (PV) research world by storm, with reported efficiencies exceeding 22% after rapid development for only 6 years.1−6 This mainly originates from the excellent properties of perovskite materials that lead to solar cells that deliver the highest possible efficiencies at the lowest possible cost. Given the recent significant progress in terms of the efficiency,6 stability,7,8 device area,8 etc., it has been predicted that PSCs could be on the market in the near future and the use of perovskite materials could soar soon thereafter.9

I just feel all "renewaly" just reading about it.

After only 6 years...

Only 6 years...

In the last 6 years we've dumped over 180 billion tons of new carbon dioxide into the planetary atmosphere, and in the 6 years before that there were (if you looked) all kinds of "solar breakthroughs" announced.

But with these "reported efficiencies" that have "taken the photovoltaic (PV) research world by storm" well, this time we've got it wired, no?

Well there is a little problem, mentioned in the next paragraph in the same paper:

However, the great promise of PSCs is being challenged because of their Pb content and sensitivity to water, which raises concerns about the potential toxicity of perovskites and their behavior in biological systems or the environment.10−12 In However, the great promise of PSCs is being challenged because of their Pb content and sensitivity to water, which raises concerns about the potential toxicity of perovskites and their behavior in biological systems or the environment.10−12 In pair s orbitals and perovskite symmetry, high ionicity, a large lattice constant, and strong antibonding coupling between Pb lone pair s and I p orbitals.16,17 The actual results after the replacement of lead with other cations are not satisfactory;13−15thus, the lead-containing perovskite is still the material of choice for PSCs. Fortunately,...

Fortunately!

...some teams have been (sic) to investigate the health risks and dangers of lead-based perovskite materials by studying every possible scenario through which perovskite materials could enter the soil and groundwater, reach the food chain, and affect biological systems. For example, Hailegnaw et al. have investigated the possible environmental effects of perovskite solar cells by exposing such devices to water with varying pH and determining the amount of Pb loss and found that the amount of lead that enters the soil is not catastrophic for the environment,10 while Benmessaoud et al. have tested health hazards of perovskite through cytotoxicity studies and underscored the critical importance of conducting further studies to investigate the effects of short- and long-term exposure to CH3NH3PbI3 on health and the environment.11While these results are merely based on simple laboratory experiments, we should do our best to avoid lead outflow.

We should do our best...

In former times, one of the main sources of lead contamination in the environment was the use of tetraethyl lead in dangerous gasoline produced from dangerous crude oil. Now the major source is lead from coal mines aerosolized in coal fired power plants...and no...coal is not dead, not even close, unless of course you like to lie to yourself, as many people do.

We should do our best...

Well the "breakthrough" PSC, perovskite solar cells can be recycled!!!!!

We're saved!!!!

That's the topic of the rest of the paper.

Here's a little process chemistry about the "green" recycling:

Organic−inorganic hybrid lead halide perovskite solar cells(PSCs) have recently taken the photovoltaic (PV) research world by storm, with reported efficiencies exceeding 22% after rapid development for only 6 years.1−6 This mainly originates from the excellent properties of perovskite materials that lead to solar cells that deliver the highest possible efficiencies at the lowest possible cost. Given the recent significant progress in terms of the efficiency,6 stability,7,8 device area,8 etc., it has been predicted that PSCs could be on the market in the near future and the use of perovskite materials could soar soon thereafter.9 from degraded devices. Because of the strong solubility of perovskite and lead iodide (PbI2) in N,N-dimethylformamide(DMF), PSCs can be easily separated and recycled into their major components. By a simple and low-energy process, including DMF washing, chlorobenzene (CB) washing, ultrasonic cleaning, and UV−ozone treatment, the used substrate including TiO2 can still be very clean and can be used to prepare the device again. After two rounds of substrate cycling ,the resulting PH PSC and M PSC still presented peak efficiencies of 11.87% and 11.03%, respectively, indicating th efeasibility of the recycling of used substrates for sustainable, energy- and resource conservation-oriented, and environmentally friendly energy production.

Yuuuuummmm...chlorobenzene...gotta love it.

It's, um, "easy." (The authors - and I do not mean this pejoratively even if it sounds so live in China, where - one has to concede - chlorobenzene might be green.

Sigh. I've lived a long time, too long maybe.

If you believe that every lead halide solar cell that ends up "distributed" for "distributed energy" will end up being recycled, I have an orange "President" who will "Make America Great Again" I'd like to sell you.

What will happen is that solar cells now on sparkling McMansions will end up in the very same place they were installed, transformed into future blighted slums a shadow of their former greatness, with the solar cells still sitting on the decaying roofs, until they collapse, whereupon the lead will leach out into the rain water collecting in the cracked and leaking foundations.

Don't worry, be happy. You'll be dead then, and none of those whomever should live in that ruined world will be able to confront you with the failure of what you believed.

Tomorrow is Friday. Enjoy the coming weekend.