5 December 2015

5 December: Plugging Christmas lights into summer sun

Solar Energy

Today’s advent researcher has discovered a way to store solar energy for long periods of time with less energy loss than current methods. This means that green energy from the glowing summer sun can be stored and used for light and heat during the dark and gloomy days of winter.

’Tis the season of lights - at this otherwise dark time of the year, streets and pedestrian areas are brightened by sparkling Christmas garlands strung across them. And, in living rooms, electrically lit trees and candles bring a coziness, "hygge", to hearts and homes. Imagine if all these lights could be illuminated with the help of solar energy that was harvested and stored during the warm and bright summer months! And if our homes could be heated by the sun’s summer rays – in the depths of winter!

The day may be nearer than it seems. Anders Bo Skov, a graduate student and published researcher at UCPH’s Department of Chemistry, is in the process of conducting research to develop organic solar cells and to store solar energy using organic colourants.

 "A year ago, we got to the point where, with the help of a molecule, we could store solar energy for 114 years. This is a really good alternative to the current method of storing energy in water," explains Skov.

Together with his colleagues, Anders Bo Skov would like to use the molecule’s discovery to produce solar thermal energy batteries that can store energy from the summer, for use during winter. Today, energy harvested using solar cells, for example, is stored in water. However, if water is stored during summer, it loses 40-50 degrees Celcius of its heat when released during the winter – not a particularly effective way of storing solar energy.

 "Specifically, we have an organic colourant that can absorb light and transfer it from form A to form B. When the colourant does so, it absorbs the sun’s light and stores it in a less stable form, like when a bow is drawn. Thereafter, it releases the energy into heat. What we’re trying to do, is find out how long we can get the colourant to hang onto the energy – without a significant loss of energy – before eventually being released as heat."

Savings on energy bills

Anders Bo Skov is also working on a solution where the colourant is used in solar panels to immediately transfer the sun’s energy to heat.

 "If you can imagine that, instead of using normal solar cells, we have solar panels where the colourant is allowed to circulate, be struck by light and then converted. When the colourant has run its course through the solar panels, its heat is released to a hot water tank that then heats a home, while unused energy is sent back to district heating plants. Thus, considerable energy savings can be achieved."

Curiosity fuels research

There’s no question that curiosity is what drives Anders Bo Skov.

 "I can’t help but asking ‘Why’?”. Whenever I hear an assertion or someone say that it’s like this or that because it is, I have the urge to ask: ‘Yes, but why is it so?’ I need to know ‘why’, so I find myself compelled to get down to researching things for myself."

While curiosity propels him, a blend of theory and practice in research are what make things interesting for Skov.

"Because we are capable of blending theory and practice, we can rapidly create a bunch of computer models during the first couple of weeks of a study. We can then make the molecule in the laboratory and check to see if our models were accurate. Thereafter, we can see how close we came and rethink our models to optimise them for the next time. This iterative process improves our models. It’s an on going process during which we deploy both theory and practice, one that makes me incredibly happy."