Oh, certainly. However, Trek (especially once you get past the early seasons of Star Trek: The Next Generation
) was not a low-budget affair for Paramount by any means. And if you're looking at where the money is going, electrical costs are a minor expense in the scheme of things.
To compare, since I have the actual production budget in front of me, the total electrical cost of Star Trek VI: The Undiscovered Country
was $432,911. That's the total cost of all the electrical expenses (lighting and otherwise) of a $29,157,511 feature film on a 54 day shooting schedule.
The television shows, in contrast, shot episodes on a 7-day shooting schedule, with a much smaller budget. Assuming that you're spending the same amount of money per day as a feature (and this would likely be less, since feature films usually have much more elaborate lighting and camera set-ups than episodic television) that's about $50,000 per episode. That's also a more or less fixed cost, since sets always need to be lit, so it's not really going to have an effect on other budget lines.
That was not the most efficient way to arrive at the point. Apologies.