14 December 2005

Significant: The insignificance lessens.

My Brazilian apartmentmate and I are trying to figure out how to economize a bit next semester. Every one knows the electricity bill can be huge, especially in the winter. But really how much are you saving if you take a slightly colder shower, or turn off the heat and use an electric blanket?

First let's assume a 10 cent per kilowatt hour rate. Now we need a tasty example. How about heating up some pão (bread) for café de manhã (light morning breakfast). I am using Portuguese because I'm using my appliances here in Brazil as an example. As I see it there are four methods of heating up my pão.

The Oven. We have a tiny one, but for all the heat it loses making the handle untouchable, I'm going to assume it is pretty inefficient. I'll assume 1 kW/hr. Time to cook: 15 minutes. Total cost: 2.5 cents

The Microwave. I would cook on high power so, 1.4 kW/hr. Time to cook: 30 seconds. Total cost: 0.12 cents

The Light Bulb. Standard 60W bulb gives .06 kW/hr. Time to cook: 30 minutes. Total cost: 0.3 cents

The Rio Sun. According to a solar car site, about 1 kW/hr on a square meter on a sunny day with the sun directly overhead... but that is a mute point since it is free.

I've order the above by the quality of preparation each cooking method gives me. Over the course of my stay here in Rio, had I used the microwave every morning instead of the oven, I would have saved $4.28 (180 days * [oven tc - microwave tc]). My time here has no value, therefore the oven is the winner!

Edit (12/16): Yeah, so my oven is gas... I guess I'll need to revise my calculations.

1 comment:

Amanda said...

If you are talking about the heat during the winter you first have to ask yourself if your heating is gas or electric. Currently if it is gas you are screwed. You are the man that does the looking up and calculations but i know that gas prices are at an all time high so therefore if your gas is electric, like it is at my apartment (HURRAY), than you can have it on as long and as much as you want and it is still cheaper than everyother person in C-ville. So check to see if you have gas or eletric heat before you start throwing around your money and your opinions. =)