Storing the Sun’s Energy in Liquid Could Change Solar Forever


The sun puts out a lot of energy, more of
it hits the earth in an hour than humankind could use in a year And we’re really not
taking advantage of it, the US got less than 1% of its electricity from solar power in
2016. If we could get that number higher, we could
run our homes, cars, toaster ovens, all with zero emissions. That’s the dream anyway, some perfect future
with limitless free energy.


So what’s in the near future for this future? Where does solar power go from here? One of the big problems is what do we do when
there’s no sun? Like on cloudy days. Or at night time. If we’re going to go all solar, we need
a way to store the sun’s energy.Usually, we’d combine solar panels with rechargeable
batteries, but batteries are pricey and they kinda suck.


So researchers in Sweden are working on how
to catch the sun’s energy in a bottle, or at least in a little tube. Those crazy Swedes developed a liquid with
an intriguing property. The molecules in the liquid react when exposed
to light and become isomers; meaning they still have the same makeup, but in a different
arrangement than normal. This new arrangement stores energy, and when
a catalyst is introduced, it shifts the molecules back to their usual structure and releases
the stored energy as heat, which could be used to warm homes at night or generate electricity,
provided enough heat is released. Recently the researchers switched from expensive
ruthenium to the more common elements carbon, hydrogen, and nitrogen to build their molecules;
this makes the process cheaper and easier.


On top of that, they’ve actually increased
their storage capacity by a hundredfold! Ok so… they could only store 0.01% of the
energy that hit it before… and a hundredfold increase means just 1.1%, but still, progress! Storage isn’t the only issue. The panels themselves are also expensive… If we could make the solar panels cheaper
that would go a long way to creating a competitive source of energy compared to fossil fuels
and other renewables. 90% of photovoltaic cells today use crystalline
silicon, making them expensive to manufacture and the process creates toxic by-products. But an entirely different approach does exist:
Using perovskites. Perovskites have a crystal structure of tetrahedral
arrangements of atoms and molecules, and depending on which elements are used they have different
properties. They could be superconductive, magnetoresistive,
or photovoltaic. Solar cells that use them are cheap and easy
to assemble and could now be on par with silicon cells in terms of energy efficiency.


But you may have noticed every rooftop in
sight isn’t covered in perovskites. That’s because they have a fatal flaw: the
cells are unstable, and extreme light levels, temperature, and humidity cause them to decompose. Even normal weather can destroy them, which
is bad because you typically see a lot of weather outside, the place where solar panels
need to be. As a result perovskite cells only function
for several months, compared to silicon cells which can last more than 25 years.


But hey, a decade ago perovskite cells only
lasted a few minutes. Again, progress! Scientists are constantly coming up with new
and ingenious ways to make the sun do our bidding, and these are just a couple of things
currently in the works that show promise. Though we don’t use much of it now, breakthroughs
and innovation could lead to a world powered cleanly and sustainably by sunlight. The future of solar power looks bright. There are crazier ideas for solar like putting
panels in space and beaming electricity to Earth, but a massive project like that would
be insanely expensive. They’re fun to ponder though, so Trace covers
some far our geoengineering projects here. Do you have a favorite renewable energy technology
that’s not quite ready yet? Let us know in the comments, so I can see
how many of you say thorium reactors, subscribe for more, and thanks for watching Seeker.

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