Storing Solar Energy in Molecules

Quote of the Day

The technology is based on a specially designed molecule of carbon, hydrogen and nitrogen that changes shape when it comes into contact with sunlight.

It shape-shifts into an ‘energy-rich isomer’ – a molecule made up of the same atoms but arranged together in a different way. The isomer can then be stored in liquid form for later use when needed, such as at night or in the depths of winter.

A catalyst releases the saved energy as heat while returning the molecule to its original shape, ready to be used again.

Over the years, researchers have refined the system to the point that it is now possible to store the energy for an incredible 18 years.

The Swedish researchers sent their unique molecule, loaded with solar energy, to colleagues at Shanghai Jiao Tong University. There the energy was released and converted into electricity using the generator they had developed.

Essentially, Swedish sunshine was sent to the other side of the world and converted into electricity in China.

Lottie Limb
December 4, 2022
Major solar breakthrough means energy can be stored for up to 18 years (

That’s wild!

It was also in late 2022 and I have been unable to find any news on it since them.

I’m a bit skeptical because thermal to electrical efficiencies are, at best, something on the order of 40%.


11 thoughts on “Storing Solar Energy in Molecules

  1. We already have a perfectly good method of storing solar energy. We call it “farming”. Grass grows in the sunshine. Cows eat the grass. We eat the cows. Corn grows in the sunshine. We eat the corn, or feed it to the cows, or convert it to alcohol to drink or burn in our engines.

    • Exactly.
      You can also turn all the bio-mass and left-overs into liquid hydrocarbons just like the earth does 5,000 ft. down through thermal depolymerization.
      Just crush it to powder, mix with 12 parts water, and boil at 500 degrees and 600 PSI for a half-hour and it turns into lite-sweet crude oil.
      Fractionally distill to separate into the desired products.(Separation by temperature and liquification point.) And one gets gas, natural gas, oil, diesel, tar, asphalt.
      One can even crack and polymerize to get the needed quantities of each.

  2. Sending your wonder chemicals to the ChiComs maybe the single dumbest thing a researcher can do.

    You just gave away your discovery.

    Dumb Ass!

    • And no wonder we haven’t heard about it for almost a year and a half!

  3. I thought this magical molecule was going to be Chlorophyll.

  4. Sounds cool. And I’m almost certain were nowhere near discovering the boundaries of thermal dynamics. Or the law of the conservation of energy.
    As you point out Joe, it’s the machines used to recover that energy that are truly the problem.
    Efficiency is something we should be all about in this world. To me, that’s where the real future is.
    Getting every drop of energy out of mass/energy conversions could solve a lot of problems we humans have.
    That, and getting rid of totalitarian communists. Which account for about 85% of our problems.

  5. It’s always good to have alternative ways to store electrical energy. The issue is one of efficiency…both physics and economics. Can this methodology be economical, is it reasonably friendly to the environment, especially when compared to oil. Can it scale efficiently. Lots of questions but it’s certainly worth investigation.

  6. I see nothing in the article about the energy density. How much heat can you store in a pound of this chemical? How much in a dollar worth? My suspicion is that to get enough stored energy to heat and power a small, energy efficient house for 24 hours, you’ll need many tons of material, costing several times as much as the house and tens of times as much as a battery pack of the same capacity. If you loaded a truck with it, the energy stored in it would be much less than the energy in that truck’s fuel tank.

    And what is the temperature released? I suspect it is “hot” like black metal left in the sun, not “hot” like steam leaving the boiler in a power plant or like the burning fuel in the cylinder of a diesel engine, and this means you’ll get lousy efficiency turning that heat into power.

    Thermoelectric generators are heat engines, subject to the Laws of Thermodynamics, which say that a heat engine must have heat flow from a heat source to a cold sink, and can only take a fraction of that heat. That fraction is the efficiency, and this is limited to a maximum of:

    (Th – Tc)/Th,

    where Th and Tc are the extreme hot and cold temperatures referenced to absolute zero. That is, you can measure them in degrees Kelvin, which is Celsius plus 273.15, or degrees Rankine, which is Fahrenheit plus 459.67.

    So lets say the high temperature released from the absorber is 150 F = 610 R, and the cold temperature is a plate at the bottom of the thermoelectric stack, cooled by tap water flowing from underground pipes at 50 F = 510 R. (Never mind the energy used to pump that water!) Now the maximum theoretical efficiency is (610 – 510)/610 = 100/610 = 16.4%. That is, over 83% of the heat so expensively stored will go to slightly warming that water, and under 17% is turned into electric power – IF THE THERMOELECTRIC STACK IS PERFECT. But real ones leak heat, letting part of it flow through by ordinary conduction without extracting a share, so they get much lower efficiency.

    OTOH, all of the heat released above about 80 to 90 F will go to heat your house in winter. You might even use a thermoelectric stack that’s only a few percent efficient to extract the electric power to run the fan and thermostat in your forced-air heating. But still, for me in Michigan, the questions are: will it collect solar heat when it’s -20F outside and 3 feet of snow just fell, how much of this stuff will I need, how much will it cost, will it weigh so much I have to reinforce my roof to put the collectors up there, and will the southward-facing part of my roof be enough area to collect 24 hours of heat in less than 6 hours of low-angle sun.

    • On the third hand, I can heat my house in the woods using another magic molecule to trap sunshine, and it’s nearly free if I count certain actions as “exercise” rather than “hard labor”.

      This molecule is chlorophyll. With sun, water (free and usually in overabundance in Michigan), carbon dioxide from the air, and a little fertilizer, it traps sun and makes trees grow. Then I get warmed (often too much!) cutting the trees, cutting the logs up into woodstove lengths, and loading it on a pickup for transportation.

      Next, I get warmed again splitting the wood and stacking it to dry. Six months to 2 years later, I can begin bringing the dried wood in the house and loading it in the woodstove, so it warms me the third time.

      But I somehow got too old for that much exercise, and now I live in a built-up area where the air would become unbreathable if everyone was burning wood on slow fires….

      • The “secret” to low pollution, slow burning fires is for the fire to be starved of fuel rather than be starved of oxygen. As in a pellet stove.

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