I'm new to this particular stackexchange, and admittedly my first answer was not quite in keeping with the general expectations. That's not my point.
The specific answer is here: Low-power-draw HD resolution video card
I'm happy to admit it does not specifically provide a low power graphics card as requested by the enquirer. However it does provide an answer that would provide the same end result, albeit a completely different way, and probably a way that the OP had not considered at all.
Over at https://bicycles.stackexchange.com/ we make an effort to salvage the good parts of a comment/answer by using comments, or by direct editing. Delete is for those answers that are beyond saving.
I'd like to politely suggest that delete should be a last response, not the first.