Even some surveillance cameras or motion sensors?
As for it being impractical, I see it more as a matter of priorities. It's impractical to believe that we can make the world safe for democracy, yet that's still a major priority of policymakers. It's impractical to engage in a war on drugs, yet we still do that anyway. It's impractical to have security screening at every airport in the country, yet we still do it anyway.
These things listed above are clearly a higher priority, however impractical it may be to expend resources on these policies. Shouldn't protecting the US power grid be a higher priority than some of these other concerns? If the government thinks that pot smokers are a greater threat to US national security than people who would sabotage our power supply, then I would say that's a very impractical, imprudent, and unwise way to evaluate national priorities.