Computer Electricity Use

Peg heard a story on the radio about an elementary student who found that his family could save $1 per day by turning off the family’s computer at night. Not only did he get an A in this science project, but the school system realized that they could save a lot of money by turning off their 500 computers after school. This sounds a little fishy. Our LWVO survey finds that just abut all schools turn off things not in use. Also $1 per day electricity savings seem huge; this is the cost of about 10 kWh. If the turn-off is for 10 hours, their system uses about 1kW.

I decided to check. Here are the data from The Texas Office of Risk Management:

Computer -------------- ----------------------- 250 watts
Monitor ----------------- -----------------------150 watts
Speakers --------------------------------------- 15 watts
Electric stapler ---------------------------------- 25 watts
Scanner ---------------------------------------- 150 watts
HP Laser Jet 4 Printer (Idle) ------------------- 250 watts
(Printing) ---------------1,175 watts

Total 840 watts when idle
1,765 watts when printing

It appears that the student’s estimate may not be far off. However, $1/day = $30/month is almost our entire electric bill.

We don’t have an electric stapler and our scanner is off when not in use. Furthermore, we have an ink-jet printer, which takes mush less energy than a laser. I figure that our system uses maybe 400-450 watts for 16 hours per day or around 200 kWh per month. which is maybe half of our electric bill. Still a lot!!

Opposition to Projects

Several weeks ago I read a story by a Baltimore Sun reporter about two proposed energy projects in Maryland. One is for a third nuclear plant at Calvert Cliffs, on the Eastern shore of Chesapeake Bay. The locals strongly support the project. Their view is that the current nuclear plants have brought good jobs to town and pay large taxes. There is no discernible effect on the health of plant employees as well as the general population. Their case is strengthened by the large reduction in greenhouse gasses associated nuclear energy and the excellent safety record of US nuclear plants. Opposition to the new plant comes from out of town and uses the general anti-nuclear arguments. As of today the project is going ahead.

The second proposed project was a wind farm in Garrett County, the westernmost county in Maryland. The turbines would have been built on state land in this mountainous region. Here the roles were switched. Out-of-towners thought it a great idea, but the locals strongly opposed it. They argued that Garrett County is a tourist region and the towers would spoil the scenery. Also, there was opposition to chopping down trees for the project. In the end the Governor canceled the project.

My reaction was the we will never fight climate change if everybody mounts his particular hobby horse.

Gasoline Usage

It was recently reported that Americans drove six billion fewer miles over a six-month period. There are 245 million motor vehicles in the US, of which 155 million are cars. If we consider both cars and trucks, the average mileage is about 17 mpg. So the average vehicle drove about 24 miles less over the six-month period and saved a little under 1-1/2 gal of gas.

Other statistics:

Americans used about 136 billion gallons of gas last year or about 550 gal/vehicle.
They also used about 7 billion gallons of ethanol.

Today's Columbus Dispatch lists the profits of the five largest oil companies in 2007. The total is about $125 billion. The US has about 150 million cars using an average of about 750 gal. of petrol per year. So the profits come out to about $1/gal.

There are adjustments to be made:

1. The US uses 43% of the world's oil (GAO).
2. These companies sell petrol in other countries.
3. Other companies sell petrol in the US.

Items 1 & 2 lower the profit per gallon and item 3 raises it. I don't have data for 2 & 3, but I find it hard to believe that the profits are less that $0.50/gal.

On Bridges and Cell Phones

Many years ago I spent an afternoon with an historian of bridges. He said that there is a cycle of bridge design. First a bridge collapses. Then a new design or material is introduced. This bridge is built with extreme overdesign to bear loads much in excess of any it might experience. But, as time goes on, standards relax and talented people turn to other fields. Then there is another collapse and the cycle starts over.

Electronic technology seems to follow a very different path. New device follows on new device with ever expanding capability. But reliability suffers (an article in the NY Times this past Sunday pointed out that cell phones and VOIT are much less reliable than land lines).

Both the reliability and obsolescence of electronic devices promote a throw-away economy. It takes energy to make these devices and energy to dispose of them. I suspect that it's not much enrgy in the overall scheme of things, but it rankles a child of the Great Depression and WWII. We were taught to make do. I think that we are better for it.