Amethyst

“If heat could be bled off of the magma chambers, cooling and solidifying them, not only would that stop the volcano from erupting, but the heat could be used to generate electric power with a geothermal energy plant. Depending on the size of the plant and how quickly it bled off the heat, this could be a very large amount of electricity - enough to power the entire US.”

This one worked, your original one did not