Graham,
I don't own a digital TV yet, but you're probably right, they should play rgb just fine, I was thinking NTSC composite overlay would be a problem. My wife and I decided that since we have low resolution eyes, (over fifty, bifocals, etc.) we don't yet need a high resolution TV, and the prices will likely fall.
Thanks for the info regarding the PV cells. Our local electric utility is going to become unregulated next year and electric prices are expected to jump significantly.

Jerry.