I am no expert on the HDMI spec, so I'm unsure exactly what features are required, but I have seen some TVs that can power the chromecast right from the HDMI po

I am no expert on the HDMI spec, so I'm unsure exactly what features are required, but I have seen some TVs that can power the chromecast right from the HDMI port, but other ones that require USB power. My cheapish Vizio LCD TV can't power the chromecast over HDMI, at least.