Let me be very clear. This is an article about saving money. It is a cost analysis of alternative lighting options for the home. This is not an article about morality, social responsibility, climate change, natural or man-made global warming, or whether or not Al Gore invented pants! I am passing no judgments on you nor anyone else based on what you choose to use. Got it? Good. Let’s begin…

I’m not going to mention the obvious actions of cutting off unused lights and appliances and messing with your thermostat to save on energy. Let’s look at how the technology of lighting options can help reduce your energy costs.

How to Save Money with the Best Light BulbCFLs and LEDs: Compact Florescent Lights and Light Emitting Diodes. OK, these are a little obvious for cutting back on energy, but do they save you money when you consider their higher costs? That’s a more difficult question to answer because you have to factor in the following variables:

Buy in price: How much does the bulb cost compared to the incandescent bulbs?

Expected life: How long should you expect the bulb to last before it dies?

Energy use: How much energy will it consume in a given time period (watts)?

Subsidies: Are there government subsidies or tax breaks for these where you live?

Energy cost: How much does your energy use cost you?

Disposal cost: Remember, CFLs are considered hazardous materials because they contain mercury vapor and must be disposed of properly.

We need to run these numbers for all of your lighting options and get a cost per time period so we can compare apples to apples.

I’m going to make up some acronyms to shorten our formula below:

pp = Purchase Price

ppk = Price Per kWh

blbh = Bulb Lifetime Burn Hours

dc = Disposal Cost

s = subsidies

We’ll use this formula to give us cost per hour:

(pp + (ppk * blbh) + dc — s) / blbh

Keep in mind, there’s not just one answer to this, and this month’s answer could very well be different from next month’s answer considering lighting prices and energy prices are always changing. Plus, if you have coupons or your local store has sales, that will factor in as well. Also, geographic location and legal jurisdictions impact the cost as these variables are different all over the world. It might be more cost effective in say, Los Angeles, CA than in, say, Chattanooga, TN.

Here’s how to figure the more complicated variables before you plug them into the formula.

Energy use pricing is a little complicated, so here’s how you figure that value. Get your most recent electric bill. If it doesn’t directly state the cost per kilowatt hour (kWh), then it should at least tell you how many kilowatt hours you’ve used. It may not even be labeled as kWh and may be simply something like “Amount Used,” like on my electric bill. Once you find that, get the total on your bill for just energy use. Some bills are broken down by electricity used, maybe a fuel surcharge, maybe some taxes and fees. Any line items that are constant and not changing based on your energy usage, don’t count those. Anything related to your energy usage, add it all up. Then, divide that cost by total kWh used. That’s your cost per kWh. If you calculated correctly, it should be around $0.04 to $0.10 or so, at least in the United States. Here’s a link that’ll give you a ballpark figure by US state.

You can also just call your local electric company and ask.

Disposal Cost: Read the directions that came with your CFLs or potentially call your electric company and ask it about the proper disposal of CFLs. Add that to your purchase price. Also, remember that if you break a CFL, it’s considered a hazardous waste zone and all sorts of ridiculous measures must take place, including evacuating your home immediately because of the mercury vapor. Some jurisdictions will require you to actually call in a real life Hazmat team. No kidding! It’s crazy! Call your local utility to find out.

Bulb Lifetime Burn Hours: This is usually printed on the packaging that your bulb comes come in, but that’s sales material and how often have you seen completely honest sales material? Surprisingly, according to ConsumerReports.org, they’re fairly accurate in their reporting in this case.

Subsidies: Call your electric company and see if it’s aware of any subsidies or tax breaks you can get for using CFLs, LEDs, or any other alternative lighting. Depending on where you live, you may get some breaks.

Once you’ve run the numbers in the formula above for all types of lighting options, then you’ll have numbers that can be directly compared and you’ll know which one is cheapest. Be warned: this may be a shocker to a lot of people, because the cheapest isn’t always the most “environmentally friendly” option. As I said, this article is about finding the cheapest alternative. Use your own judgment on whether you want to use a more expensive option, assuming, of course, that your cheapest option is not the friendliest to the environment. Also, don’t forget, CFLs are hazardous when broken, so assume that you’ll break about one or two percent of them and factor that cost in, but that’s an article for another day for another purpose.

What kind of lighting are you using and what cost results did you get from the formula here? Let us know in the comments below.