Energy prices for Texas often range in price between 5.85 to 14.76 cents per kWh subject to market conditions and your location, these prices will not be guaranteed and are only used as examples.
Most folks don't really pay too much attention on lighting as they think that your lights are not consuming lots of energy. Light bulbs can have a large effect on your monthly bills because they can consume a lot of energy if they're used often. If you're currently making use of incandescent bulbs, you must replace them with LED bulbs or CFL.
It will also be better if you will substitute your lights if you still incandescent bulbs. It's always safer to choose CFL or LED bulbs because the incandescent bulbs discharge 98 percent of the energy that they consume to heat.