8. Alternative Energy
Just a small technical factoid about the D'deridex-class that often gets overlooked: The Romulan warbird does not use Star Trek's traditional mode of warp drive.
A big plot point in Star Trek: Discovery's third season was the spontaneous and catastrophic destruction of most of the dilithium crystals in the galaxy, rendering warp drive all but useless (except when the plot needed it). Aside from the Borg's use of transwarp, the only other major power in the Star Trek Universe that did not use this dilithium-based warp drive (and should therefore not have been quite so affected by The Burn) was the Romulan Empire.
According to The Next Generation episodes "Face of the Enemy" and "Timescape", as well as Deep Space Nine's "Visionary", Romulan warbirds were powered by "forced quantum singularities". Eschewing the traditional matter/anti-matter reaction (regulated by dilithium crystals), Romulan warbirds' propulsion systems were built around artificial blackholes that were kept in precise balance to avoid giving away cloaked Romulan ships.
Of course, like all good Star Trek technology, this ingenious mode of transportation was not without its setbacks, causing timey-wimey temporal distortions in both "Timescape" and "Visionary".