Incandescent lighting:
The most common “traditional” type of light bulbs used in most homes are standard incandescent globes. These emit radiation evenly and continuously over a range of frequencies far larger than is visible to our eyes. A considerable amount of energy is thus wasted because we can’t see most of the radiation being emitted. A large amount of this invisible, wasted energy is given off in the form of heat. Halogen lighting is one of the most power hungry types of incandescent lighting because the light emitting filament is heated to extremely high temperatures. Incandescent lighting is very similar in nature to the light from the sun. Incandescent lighting thus appears more “natural” to most people. Typical incandescent bulbs for home use require 40-100W of power to operate, but halogen bulbs can have power ratings of 300-500W!

Fluorescent Lighting: 
Fluorescent lights use about one sixth of the power of an incandescent bulb to produce the same amount of light. The two most popular types are the older "neon tubes”, and the modern small “energy saver” bulbs. They last about six times longer than normal incandescent bulbs as well. Fluorescent bulbs don’t emit light evenly at all frequencies (colours) across the visible spectrum the way incandescent lights do. Light is simultaneously emitted only in three or four distinct narrow bands of colour which your eye combines into one colour. This can be problematic when illuminating certain coloured objects. Another problem which affects older types of fluorescent lighting is they flicker quite distinctly. Some people may find fluorescent lighting irritating for these two reasons. Fluorescent bulbs use 8-40W of power.

Light Emitting Diodes (LED’s):
Modern LED’s are becoming more and more powerful and are fast approaching the point where they can be used in normal domestic lighting applications. They can’t quite yet match fluorescent lighting in terms of amount of light emitted for a given amount of electricity consumed but they are currently very close. The main benefit of LED’s is their very long life. They typically last almost ten times longer than energy saver fluorescent globes. LED’s emit colours  accross the visible spectrum very unevenly with a typical large peak at the blue end of the spectrum and a second lesser peak at the yellow/red part of the spectrum and a large dip between the two. This results in the same problem as fluorescent lighting where certain coloured objects become difficult to see and the colour of the light appears unnatural and irritating to some people. A single LED typically uses 1-3W of electrical power. In order to produce enough light, more than one LED is normally used in a bulb, so their power consumption is typically about the same as fluorescent lighting for the same amount of light.

Surviving a Power Failure

The big problem with regards to domestic lighting is that you are literally left stumbling around in the dark when the power fails at night. Even simple routine activities such as eating become a challenge. One needs some form of alternative power source to provide light in at least the most commonly used rooms in the house if the mains power fails regularly.

Energy Saving Tips

Convert to low energy bulbs where ever practical. Especially try and replace halogen bulbs where possible. Low energy bulbs will also make it practical to use battery power as an alternative power source during power failures (incandescent bulbs use up the battery capacity six times faster).

Switch off lighting when it is not required. Day/night sensors can ensure that outside area lighting is switched off automatically when the ambient light becomes bright enough. This can save some energy if you are not normally present to switch those lights off when that happens. Only switch on lights in rooms when you are in them.

Suitable Alternative Sources of Power

Battery power: You can provide adequate power to five 11W low energy bulbs for 10hrs using a single standard deep cycle lead acid battery without discharging the battery too deeply.  If you wanted to power more lights or other appliances, the running time available would reduce accordingly, unless you added more batteries of course.  

Solar Panels: If you charge your batteries using a solar panel instead of using mains power, then you will achieve a permanent reduction in demand on the country’s electrical power capacity. Solar panels also enable you to endure power failures that persist longer than a day because your battery will charge as soon as the sun comes out again even if the power doesn’t return.  Some inverters and solar regulators have built in mains chargers as well which will charge the batteries from the mains in the event of poor weather.

Generators: Of course virtually any requirement for alternative electrical power can be satisfied using the appropriate generator

Wind Turbines:  If you live in windy rural area, a wind turbine is an ideal source of alternative power.