Virtual Power Waste － Standby Power

Recently, I saw an article talking about how to save electricity bill by unplugging appliances after use. It shows that a large number of appliances continuously consume power even though they are switched off. This power consumption is called “standby power”. Therefore, I found some information about this topic. Here is a good website discussing standby power (http://standby.lbl.gov/standby.html), it gives measurement results of standby power of many residential appliances, explains how standby power come from, and provides some useful suggestions to cut down the standby power. However, seeing is believing, I decided to measure some appliances that are assumed to consume more standby power than others appliances in my house. The following is the measurement results:

 

It is surprising that two LCDs with the same panel size consume tremendously different standby power (almost 5 times). Perhaps standby power is unrelated to the panel size; this is different from what I thought before. In addition, my electronic fan consumes more standby power than I expected. Maybe traditional mechanical-controlled fans consume less standby power. I think I should consider how much standby power is consumed when we want to by new appliances next time. Otherwise, adopting suggestions from the above website are possible ways to save our wallet.

Many ways to reducing electricity use

Steps	Business	Residential
Turned off extra lights	80%	78%
Raised the temperature setting of air conditioning	51%	38%
Postponed use of large appliance or equipment	42%	N.A.
Unplugged appliances or electronics when not in use	40%	42%
Pre-cooled rooms prior to peak times	36%	50%
Closed draped or blinds	24%	21%
Rewarded employees for energy conservation during peak times	9%	N.A.
Postponed laundry or dishwashing	N.A.	80%
Cooked in microwave or grill instead of oven	N.A.	23%

Source: Connecticut Light & Power

Traditional rice cooker v.s. Microwave

The debate has been going on in our office since someone brought a rice cooker to reheat the lunch in addition to the microwave ovens we used to use. Bringing in lunch boxes has really been a trend since people are so concerned about safety eating out side and also avoiding the fatty fast food.

Which is better for reheating food, Microwave or rice cooker? Which one use less electricity? People on the rice cooker side said that they get more even and thorough heating, saving in energy too. Microwave guys say they use less time and hence less energy. Rice cooker guys also say the radiation is a concern.

To find out the answer, our smart tech brought in a power meter. So the competition was really heated up. For a lunch box near a pound taken out from a cooler, it turned out to be a 4 minute microwave heating that consumed 0.081 KWh comparing to an 8 minutes rice cooker heating of 0.11KWh. Do we have a winner?

Our smart tech added that is was not really fare to conclude the winner. He said the rice cooker is designed to let the temperature rise to very high at the end of the cooking process which is the most effective part of heating up the food, and then let the heat transfer to the food after the automatic switch shuts off. That why we need to let the food stay in the cooker for 10 minutes before we take out the rice to eat. In other words, we can let the rice cooker to cook only one minute and allow it to go through switching off  and let the high heat transfer happen. That’s the most efficient use of energy. But of course, the process takes much longer, not really practical when people are in line waiting to use it. When at home, this is the proper way to uses less electricity.

So, do we have a winner?

Switch off coffee machine when it’s not used. Don’t use it for keep warming coffee

Do you know where to start in the house to save electricity? If you have a coffee machine and keep it for warming coffee, TURN IN OFF!! Adjust your drinking habit to save a few buck is definitely worth while. Most people don’t drink a cup of coffee every few minutes or even every hour. Very few coffee machines have thermostat except the expensive ones.

 A lot of people use electrical water pot that keeps water close to boiling, its time to switch to thermos bottle. That’s a real electricity hog. Although it has a thermostat but it is on most of the time.

How to save energy from my daily life?

 How much electricity does my computer use? How much do I pay for using it? I am more and more concerned since I leave it on more and more. I do more and more download while I am away, and keep it on for my PS3 to access it. My electrical bill is going up but I am not sure that comes from the computer.

I looked for the power consumption everywhere but they all gave me estimate based on my usage in a day. If I use the number 85 watts for 24 hours, that a lot! My computer do go high and low, and goes to suspend sometimes. They all advise to shut it down while not using it. Sure. But I really want to know how much do I pay for the convenience I got.

Is there some data how much exactly a computer use for reference?