Usually, researching a technology never has any drawbacks. With your power drain calculation, each research seems to exponentially increase the power draw of shields (apparently by 2 dB per level). Therefore, researching a shield size technology might cause a powergrid to go beyond its limit, especially when researching shield size techs early in the game and/or needing/having a lot of turrets.

This also leads to the related problem of griefing: On a coop server, a griefer might research several levels of shield size early on, and cause all turrets to place a big drain on the power grid.

Could you perhaps implement a global setting allowing the shield size to be downgraded to a level below that currently researched, or some other mitigation measure?