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MIT scientists propose power storage using cement blocks
(www.datacenterdynamics.com)
This is a most excellent place for technology news and articles.
naturally it depends on the walls and house layout, but just to have an idea: assuming a concrete thickness of 20cm and 4 external walls of 20m x 3m each:
0.2 * 4 * 20 * 3 = 48m^3
probably in the 100-200m^3 ballpark if we count internal walls, which are thinner, but cover more total length.
And I know walls are usually not pure concrete, but functions like energy storage could very well change how we build them.