IMHO sci-fi = set assumptions, follow them consistently to conclusion, telling an interesting story as a byproduct.
I don't think all science must be true (otherways old books would lose sci-fi status as we discover things contradicting them), but it must be consistent with the assumptions, and the assumptions should be "elegant".
And if you have technology, that can trivialy be abused for infinite power after 5 minutes of thinking - people in the story should be abusing it too, or there should be reasonable explanation why it doesn't happen.
I don't think all science must be true (otherways old books would lose sci-fi status as we discover things contradicting them), but it must be consistent with the assumptions, and the assumptions should be "elegant".
And if you have technology, that can trivialy be abused for infinite power after 5 minutes of thinking - people in the story should be abusing it too, or there should be reasonable explanation why it doesn't happen.