[sionnsar]

Why is lava drying interesting or important?

It doesn't "dry," it "cools." As the article notes:

...it will allow scientists to observe directly how granites are made. ... It is hoped the site can now become a laboratory, with a series of cores drilled around the chamber to better characterise the crystallisation changes occurring in the rock as it loses temperature."

Direct observation has been key to much advancement in science (Latin for "knowledge"). In this case they can repeatedly observe what's never been seen before and at best could only be only inferred.

[uncommonsense]

I stand corrected - it looses temperature. Why is that interesting? Weren't they looking for geothermal energy? Seems like they found it, but the lava drying - sorry - loosing temperature seems to have won their attention.

BTW, the lava puns are pretty funny, especially after reading about Germany's bond issues.