I use air power, Del Aire is no longer, but California and Oregon Coast sells the EZ-Air system, better than the Del Aire.
The air motors are small:

You power them from 40 psi. You can buy small toggle switches to control the turnout, look just like an electrical toggle, but have small "barbs" for the air hose on them.
Your air can come from a compressor, or you can run for weeks from an inexpensive air storage tank:

See my site for more info and links: (this is the lowest maintenance and most weatherproof way to remotely control switches)
http://www.elmassian.com/trains-mainmenu-27/track-mainmenu-93/air-operated-switches-mainmenu-101
Regards, Greg