They appear on the turrets automatically, and do not display anything once fully charged. Open up your power grid, and you should see something with a shield icon 'producing' 0kw of power, and something with the same icon consuming some amount of power. If you see the power entries, the sheilds are there. As for the 'total, 0kw' thing, that's a bug in the code where a table value isn't getting updated right, and I can't be bothered to track that one down right now. That variable is only used for that debug output, so it's not vital to the mod working correctly.
