The difference between an energy saving bulb and a standard light bulb
Energy saving bulbs have been around for a couple of years. But they only got popular in 2007 after the Australian government decided to ban standard bulbs and replace them with energy saving bulbs. This reduces carbon dioxide emissions, which is enviromentally friendly. US and European governments liked this idea. Energy saving bulbs are said to be 5 times more efficient than standard bulbs. I find this to be exaggerated. When I compare a 12 Watt energy saving bulb with a 60 Watt standard bulb, I find that the latter is brighter. So, even if the energy saving bulbs are not really 5 times more efficient, as claimed by the industry, you still save a lot of energy compared to standard bulbs.
Standard light bulbs
A standard bulb is an incandescent light bulb. Its light is produced by a thin annealing metal wire. But in addition to the light, a lot of heat is produced. Actually, only around 3% of the energy is converted into light. Nevertheless, we have been using this light source for 150 years. Its use is questioned now only because of the development of more efficient light sources like diodes and energy saving bulbs.
Energy saving light bulbs
Energy saving bulbs are either compact fluorescent tubes or LED bulbs. In both cases, the light is produced by electron jumps within atoms. This leads directly to light emission. This works because, according to the laws of physics, eletrons hold a specific amount of energy corresponding to their position. When they jump to a different position where they hold less energy, the difference in energy is emitted as light. The electrons are made to jump by applying an eletrical tension. No heat is produced during the electron jumps; only light. That is why this technique is more efficient than light emission through an annealing wire. What a great idea!