Can these 35-ton bricks solve renewable energy’s biggest problem?

I must be calculating this wrong, I get:

400ft * 35tons * 2000lbs/ton * 0.00037661609675872 watt hours/ft. lb = 10545 watt hours.

that's only about 10kW hrs, what you get in a just one very compact Sonnen battery (https://sonnenusa.com/en/sonnenbatterie-eco/).

This doesn't seem like much. Did I make a mistake somewhere?