From [2]:
Cement manufacturing is highly energy- and emissions-intensive because of the extreme heat required to produce it. Producing a ton of cement requires 4.7 million BTU of energy, equivalent to about 400 pounds of coal, and generates nearly a ton of CO2. Given its high emissions and critical importance to society, cement is an obvious place to look to reduce greenhouse gas emissions.
Ignoring the geographical problems, could using the power source from which energy is stored for these devices also be used to manufacture the concrete, or would you be constrained by the power plants ability to output enough energy intensity to produce concrete?
If feasible to do, then for the geography issue, would the CO2 output from lengthening the trucking route and/or high voltage transmission lines to the storage site possibly overcome the cement issue overall? If the power is ~free, loss in transmission is less important, but then you have to consider the output of manufacturing and installing transmission lines also. Although, perhaps there's spare capacity on some lines.
Actually, once the blocks are manufactured, you can ship them anywhere.
Complicated.