|
Light Bulb Cost Adjusted for Inflation |
 |
 |
 |
|
Written by Administrator
|
|
Wednesday, 09 March 2011 19:56 |
 I previously wrote up a comparison of four different types of light bulbs and their relative costs and benefits. That analysis did not, however, take into account inflation over the replacement cycle. So I've developed a new interactive chart which considers the impact of inflation on the cost of bulbs and electricity to determine how they will stack up in real life. Refer to the previous article for other attributes of the different types of bulbs beyond monetary cost.
First let us assume a constant inflation rate of 2% (compounded annually), which is on the low to average side. We will also assume that each light bulb is lit for five hours per night, every night of the year. And our initial electricity cost will be 10 cents per kilowatt-hour. You can adjust these assumptions to see how the total costs change. For example, what happens if the Fed's "quantitative easing" causes inflation to rise to 10% annually? What happens if you reduce your usage to 4 hours per night?
| | Incandescent | ESL | CFL | LED |
| Lifespan (hours) | 2,000 | 10,000 | 10,000 | 50,000 |
| Lifespan (years) |
|
|
|
|
| Electricty (Watts) | 40 | 12 | 10 | 8 |
| Initial Bulb Purchase Price | $0.60 | $13.00 | $3.00 | $18.00 |
| KWh Used Over 50k Hours* | 2,000 | 600 | 500 | 400 |
| Bulbs Needed to Last 50k Hours* | 25 | 5 | 5 | 1 |
| Bulb Expense Over 1 Years* |
|
|
|
|
| Electricity Cost Over 1 Years* |
|
|
|
|
| Total Cost After 1 Years* |
|
|
|
|
| Savings Over Incandescent Bulb |
|
|
|
|
*The lifespan of a single LED bulb
There are several conclusions to draw from this. Firstly, even with 0% inflation (or even mild deflation), LED bulbs will save you money over the life of the bulb. As the inflation rate increases, both the total dollar figure and the percentage savings increases significantly. Interestingly, the less you use a particular light fixture, the more important it is to upgrade to a more efficient type. This might be counter-intuitive since it may seem like if something is used very little, its efficiency isn't as important. However, the longer the inefficient bulb lasts, the more it will cost throughout its lifespan since inflation will impact it more than if it had expired quickly. That said, if you only use a fixture 1 hour per day, then the LED lifespan of 137 years will likely far outlast your own, so you probably won't care too much about the savings to be had after you expire. This just about enters the realm of legacy planning. Nonetheless, the principle remains that if you have lots of fixtures that you use for less time each, it is even more important to suffer the upgrade cost than if you have fewer fixtures used more often. Over time, the savings will be substantial. Moreover, the cost will be well-defined and future budget planning will be more predictable. Certainly if you're anticipating higher inflation in the future, upgrading your light bulbs now will pay significant dividends as rates increase.
|
|
Last Updated ( Thursday, 16 June 2011 01:48 )
|
