Storing Solar Energy Indefinitely: A “New” Energy Storage Approach from MIT Moves Forward [VIDEO]

We all know about solar thermal and solar photovoltaic energy, but MIT is coming back to a solar energy idea that was dreamt up decades ago but left on the bench due to our inability to gather and make use of it in a practical and economical way.

“This is the thermo-chemical approach, in which solar energy is captured in the configuration of certain molecules which can then release the energy on demand to produce usable heat,” David L. Chandler of MIT reports.

The big advantage of this approach is that the heat-storing chemicals used can store the heat for years. In the normal solar-thermal approach, even with a lot of insulation, heat leaks out. Additionally, the process is reversible in this approach and the energy can be easily transferred from one place to another. So, it can be collected in a place ideal for collecting the energy but then used wherever needed.

In an extreme example demonstrating this approach’s advantages, Jeffrey Grossman, the Carl Richard Soderberg Associate Professor of Power Engineering in the Department of Materials Science and Engineering, said: “You could put the fuel in the sun, charge it up, then use the heat, and place the same fuel back in the sun to recharge.”

Here’s a little more history on the thermo-chemical approach and MIT’s recent breakthrough:

Researchers explored this type of solar thermal fuel in the 1970s, but there were big challenges: Nobody could find a chemical that could reliably and reversibly switch between two states, absorbing sunlight to go into one state and then releasing heat when it reverted to the first state. Such a compound was discovered in 1996, but it included ruthenium, a rare and expensive element, so it was impractical for widespread energy storage. Moreover, no one understood how the compound worked, which hindered efforts to find a cheaper variant.

Now researchers at MIT have overcome that obstacle, with a combination of theoretical and experimental work that has revealed exactly how the molecule, called fulvalene diruthenium, accomplishes its energy storage and release. And this understanding, they said, should make it possible to find similar chemicals based on more abundant, less expensive materials than ruthenium.

The problem is still finding an alternative to the very rare and expensive ruthenium, but the researchers from this project are much more hopeful now that they can find an alternative.

According to Grossman, the next step is “to use a combination of simulation, chemical intuition, and databases of tens of millions of known molecules to look for other candidates that have structural similarities and might exhibit the same behavior.”

Interesting news.

For more on the technicalities of this approach and other potential challenges to widespread use, read MIT’s story or the academic article published in the journal Angewandte Chemie: Mechanism of Thermal Reversal of the (Fulvalene)tetracarbonyldiruthenium Photoisomerization: Toward Molecular Solar–Thermal Energy Storage

via CalFinder Solar

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