Stick to a higher-watt bulb for task lighting, and a lower-watt one when you want to light up an object of art or an arrangement of plants - it will generate less heat and keep thr room cooler.
Compact Fluorescent Lamp(CFL)
CFLs have a longer life, use 75 percent less energy, produce less heat and yet emit a warmer light than a regular light bulb. Most have a one year warranty so get the store to write the purchase date of the lamp.
Fluorescent Tube Light(FTL)
A fluorescent tube light is more energy-efficient than an incandescent light bulb and suitable for constant lighting, say in a kitchen. The lumen output of a 40 watt tube and a 100 watt bulb is the same. So about 60 percent of energy can be saved by using a tube.
The bulb is filled with halogen gas which emits brighter light and gives the bulb a longer shelf life. These lights have a high color-rendering index, making them closest to natural light. On the flipside, the halogen emits a lot of heat.
There is nothing better than large windows or skylights that let natural light in. However, it is good to avoid south or west facing windows as they tend to take in a lot of heat and glare.