Compact Florescent Lightbulbs

Item: Switch to Compact Florescent Lightbulbs
Category: Energy Savings
Level of Difficulty: Easy
Cost: $2.00 per light bulb
Est. Annual Savings: $9.20 per bulb
Est. Return on Investment: 2625% over 5 years
Est. Payback: 2.6 months for each bulb with modest usage

OK. Low hanging fruit is always nice, so we'll start with this one...

Converting the modest usage light bulbs in your home to Compact Florescent Light bulbs (hereafter known as CFLs) is simple, low cost, environmentally friendly, and is an easy way for individuals to take a step towards energy independence for the United States.

I'm not going to suggest that you switch every bulb in your house to a CFL right away, because the truth is that some of them you just don't use enough to warrant replacing the current bulb before it burns out on its own (think of the bulb in that crawlspace where you store holiday decorations). However, once a bulb DOES burnout, you should always replace it with a CFL.

Take note of the lightbulbs in your house that get significant use. These probably include bulbs in your living rooms, bedrooms, bathrooms, hallways, and kitchen. Of particular interest are the multi-bulb fixtures - like overhead lights, bathroom vanity lighting, and lights in ceiling fans - and high use single bulbs. Do you have an outside light that you ALWAYS leave on? Get a count of all of these lights.

Once you have a count, you know how many CFLs that you are going to need. When buying CFCs, it is important to note that there are three main types of CFLs:
1. Cool Light
2. Soft Light
3. Day Light

Cool Light Bulbs tend to have the "weakest" feel to the quality of light. Soft Light is similar to Soft White light bulbs that you may already be used to. Day Light is the "sharpest" light of the three.

In general, the Day Light bulbs can be annoying to look at directly, and you may only want to use them in places where the light generated from these are diffused through a lamp shade (or by other means).

Home Depot (and presumably Lowe's) has each of these types of light demonstrated for you in the section of the store where these are sold. The lightbulbs are color coded to these types of lights so that you can easily select the bulbs that you want.

CFLs are also sold in "Equivalent Watts" so that consumers can try to compare apples to apples when it comes to replacing their existing lightbulbs. If you are replacing a 100 watt soft white regular lightbulb, you may want to consider the 100 Watt equivalent Soft Light CFL.

An additional benefit of switching to CFLs is that you can place 100-watt equivalent lightbulbs in light sockets that are only rated for 60-watts or lower. The watts refers to the electrical load that the light is rated to carry. Since CFLs use between 20 - 25% of the electricity that a traidtional lightbulb uses, you can upgrade the light in these outlets, get more light and STILL save money.

So how much can you save per lightbulb replaced? The answer is "It depends". It depends on how much you use the lightbulb you are replacing. Here's a quick way to estimate how much you can save in electricity on each lightbulb you replace.

Calculate Total Watts used per year
Example:
8 60 watt bulbs used an average of 4 hours a day (8 * 60 * 4 * 365 = 700,800)
6 100 watt bulbs used an average of 4 hours a day (6 * 100 * 4 * 365 = 876,000)
6 75 watt bulbs used an average of 4 hours a day (6 * 75 * 4 * 365 = 657,000)

Cost of electricity per kWh (Kilwatt hour): $0.105
Cost of electricty per year for those 20 bulbs: 2233800/1000 * $0.105 = $234.55
Cost of electricity if using equivalent CFCs is about 78% less at: $50.82
Total Savings for those 20 bulbs: $183.73 or ($9.20 per bulb per year)

A few things to keep in mind. This is the AVERAGE saved per bulb per year. The bulbs you use more often save you more and the bulbs you use less often save you less. Some other things to consider. Your savings are affected by the season...since CFLs don't generate nearly the same heat that regular lightbulbs do, the lightbulbs DON'T help to heat your house in the winter (which would reduce the electricity you spend to heat your home). However, this is offset by the lightbulbs NOT heating your house in the summer (which requires your AC to work harder and costs electricity). In other words, you will notice your savings more in the summer than you do in the winter.

The Daylight CFLs (most expensive) cost about $2/bulb when not on sale.
The Incandescent 60 watt lightbulbs cost about $.25 each (but don't last as long).

Assuming the incandescents DID last as long, you are paying an additional $1.75 to save $46 ($9.20 per year for 5 years). You also save on the cost of all of the incandescent replacements you would have needed and the time and effort required to replace them when they burn out.

Estimated Passive income generated by switching each moderately used lightbulb over 5 years: about $45

My assumptions, in case you want to adjust to your situation:
Cost of a single regular 60 watt lightbulb at Home Depot: $.25
Cost of a single regular 13 watt CFL at Home Depot: $2.00
Estimated Life of regular bulb: 1,000 hours
Estimated Life of a CFL: 7,000 - 10,000 hours
Estimated Electricity Usage of a regular 60 watt bulb:
Estimated Electricity Usage of a CFL 60 watt equivalent: 13 watts
Cost of Electricity: $0.105 per kWh