##

Saving the Earth via choice of light bulb

- 1 15-W fluorescent fixture produces as much
light as 1 75-W Incan bulb.

- The fluorescent bulb lasts for 10,000 hours
- the Incan bulb lasts for 1000 hours

- The fluorescent bulb costs $15.00 (which is why
no one buys them)
- The Incan bulb costs $0.75 (which is why everyone
buys them)

Now lets calculate the total cost over the lifetime of
the fluorescent bulb assuming a cost rate of 10 cents
per KWH.

- Fluorescent bulb = 10,000 hours * 15 Watts =
150 KWH * 10 cents per KWH = $15 + the cost of the
bulb total cost = 30$

- Incan bulb = 1,000 hours * 75 Watts = 75 KWH *
10 cents per KWH = $7.50 + the cost of the
bulb total cost = $8.25

- Now multiply this by 10 = $82.50

So, over a 10,000 hour period, the fluorescent bulb
has a total cost of $30 and the Incands have a total
cost of $82.50.
You just saved 50 bucks as well as 600 KWH of energy.

Clearly always use fluorescent bulbs if you are
interested in saving energy and money.

Previous Lecture