q about effective lightning

Hi,

I am still on my quest to add more lightning to my 36" tank.

I am torn between a 96W single light or a 2X55W bulbs solution.

What is the effective watt for the 2X55W considering that they are I
believe 21" PC?
Obviously it is not 110W although I will be paying for that rate.

Is the 96W a better option, although it costs more to buy and the bulbs
probably cost more to replace, even if they last for a year or two?

Plant wise, will it make a huge difference the 96W versus 55WX2 combo?

I would imagine the 2X55 would still provide enough light for healthy
growth while not promoting algae growth too much compared to the 96W!
Is this a correct observation?

Would it impact the plant cycle if instead of having the 2X55w on for
12 hours to only 11? It would be a way to reduce hydro costs.

Let's read your opinions.
Thanks