I know that 12 volt or 24 volt systems are common for exterior lighting, but with all the stuff inside I'm wondering if there are systems for wiring low voltage lighting indoors. It seems like the logical approach to LED lighting to achieve maximum energy efficiency at minimum cost to have a direct wired transformer supply low voltage to a circuit of LED lighting fixtures at lower voltage.
The apparently more common approach seems to be the use of regular 120 volt fixtures and install something that plugs into the same socket as incandescent lighting, and thus each bulb requires its own transformer to step down the voltage, and therefore you pay for a $25 transformer with each $0.25 bulb.
I'm not planning on doing this soon, but if there's a way I can understand what would be involved so I can plan for future expansion I'd be interested.
And if I was to come up with my own setup if none exists on the market, would it be feasible to adapt an exterior system and/or use parts from Radio Shack, and what section of NEC should I study to understand what code applies... Would anything prohibit such a system?