Energy News Roundup: Solar Cell Efficiency Up — Gas, Coal, & Oil Down

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It’s been a roller coaster of a week for the energy markets, so first the good news: a solar research team at Hong Kong Polytechnic University has just laid claim to the highest conversion efficiency yet for solar cells based on perovskites. The new marker is 25.5 percent. The rate was only 3.8 percent in 2009 when researchers around the world began focusing on perovskites, and the prospects look good for even more improvement in the future.

solar cell efficiency Hong Kong

Annealing Your Way To A Better Solar Cell

For those of you new to the topic, perovskites are a class of synthetic crystalline minerals. The structure is based on naturally occurring perovskite, which was first discovered in the Ural mountains in the 19th century.

Perovskites are cheap and easily synthesized, and their ability to convert solar energy to electricity makes them a good target for replacing more expensive materials such as silicon.

Another cost-reducing option is to combine perovskites and silicon in the same solar cell, which is the focus of the new Polytechnic solar cell efficiency breakthrough.

To fabricate the new cell, the team relied on the ancient art of annealing, a common practice in metallurgy that involves heating a material and then letting it cool slowly.

That’s a lot trickier than it sounds, since the cooling process needs to be precisely orchestrated in order to tune the material into the desired state.

It took a while, but in 2014 the Polytechnic team developed a low-temperature “dry” oxygen annealing process.

The basic idea behind the new solar cell is to use a top layer of perovskite to convert short wavelength photons, while letting longer photons through to a bottom layer coated with silicon.

Biomimicry also comes into play. The whole thing is topped off by a “haze film” based on the surface structure of rose petals, enabling the solar panel to engage more photons.

For next steps, the team will focus on improving the power conversion efficiency, and on tweaking the fabrication method for commercial scale operations.

Now For The Bad News: Peabody Coal Crashes

The falling cost of solar power is not good news for the fossil fuel industry, and here in the US conservative pundits and political leaders can often be found blaming President Obama’s clean power policies for job losses in the domestic fossil sector.

The latest big news occurred just last week, when global coal leader Peabody Energy declared bankruptcy.

However, despite the outpouring of outrage from the usual suspects, our friends over at ClimateWire have been talking to financial experts and the consensus is that the fossil sector is eating its own:

Cheap and plentiful natural gas, as well as an oversupplied market of inexpensive coal — not environmental regulations — are the primary forces behind Peabody Energy Corp.’s bankruptcy and others in the U.S. coal industry…

CleanTechnica would also like to point out that in some regions of the US, the coal industry began bleeding jobs long before the Clean Power Plan with the advent of labor-saving mining practices. In Appalachia, for example, one study puts coal employment at a peak of 130,000 in 1940, dropping to 14,000 by 2014 even though output increased.

More Bad News For Oil

In the petroleum industry, US producers have been suffering a thousand cuts from oversupply in the global market, and the downward spiral shows little sign of abating.

In the latest development, Fuel Fix has more bad news for oil:

Oil tumbled by the most in two months after output talks Sunday between the world’s biggest producers ended without any agreement on limiting supplies, a diplomatic failure that threatens to renew the rout in prices.

…Discussions stumbled after Saudi Arabia and other Gulf nations wouldn’t agree to any deal unless all OPEC members joined including Iran, which wasn’t present at the meeting, Russian Energy Minister Alexander Novak told reporters.


Even before the talks fell apart, uncertainty over the outcome bedeviled the global market. Last week, Fuel Fix reported that in terms of active drilling rigs, the US is now at its lowest level since record-keeping began in 1944.

The current total of 440 includes 351 oil rigs and 89 gas rigs, down 78 percent from a peak of 1,609 in 2014.

That peak activity is still haunting the industry, as existing wells are continuing to produce at a high rate relative to demand.

In the context of the global energy market, solar power has a very small role to play in this classic boom-and-bust cycle.

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Image: via Hong Kong Polytechnic University.

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Tina Casey

Tina specializes in advanced energy technology, military sustainability, emerging materials, biofuels, ESG and related policy and political matters. Views expressed are her own. Follow her on LinkedIn, Threads, or Bluesky.

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