Solar module prices reached a new low this week, says Leen van Bellen, business development manager Europe for Search4Solar, a European purchasing and selling platform for solar products. He tells pv magazine that prices will remain low in the short term.
Using the remaining 99% of the cost to bury batteries underground would seem reasonable.
Underground construction generally isn’t cost effective. It costs way more to get dirt and rock out of the way than just building a frame upwards. There might be other reasons to do it, but you want to avoid it if possible.
The underground suggestion was only to counter the argument of space usage.
Batteries can be containerized in modules, with a turnkey connection that remains mobile. Solar can use those containers as support structure. Hydrogen electrolyzer/fuel cells can also be built in same containers.