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Measuring the Energy You Use?
centdollarman asks: "Everyone keeps talking about how energy is being wasted here and there. Energy bills keep soaring for me, and now I'm back to paper and pencil: just taking notice of the power meter values. Mine is nice, as it has a cute LED that blinks at 1/1000 of a KWh. However, there has to be a better way to do this, and I've started searching the web for someway to count my usage, automatically. Of course, this is easier said than done. It would also be nice to have some way to (cheaply!) measure the power consumption of a single device."
So, for the energy conscious among us: how are you measuring the power you use?
http://www.thinkgeek.com/gadgets/electronic/7657/
The Datacentre we have our kit in has these small LED based ammeters on each of the power strips.
E nergy_Devices.html?gclid=CJ2il5S3r4cCFTpsEAod3n1L- Q8 3,1324,1328&mid=4084
:)
Very handy for figuring out where our power budget is going.
Google provides the following in quick order
http://www.energyoptimizersdirect.co.uk/acatalog/
http://www.blackbox.com/Catalog/Detail.aspx?cid=1
Enjoy
Help! help!, the termites are eating my DRAM!!!
I agree with some other comments about conserving energy as a good way for going and stopping your bills from going up... as for a way of measuring you can see that kill-a-watt device some people have shown, it seems like a good idea. One issue is that it doesn't really tell you how much power things like lights and your oven use though (because they don't have standard plugs - at least not here).
The only way I can think of doing that, although it would be a hastle, would be to switch off all items in your house and verify that with your little light not blinking, then switch your oven on and time how long it takes you to use a Watt/hour. Then switch that off and see about the lights you would normally have one. This would give you some ideas on how much these things use. As a way of reducing the amount of power that they use you could get energy efficient bulbs (they cost more innitially but less in the long term) and if you need to replace your oven you can look for the most energy efficient one you can find (and if gas or electric is cheaper in your area angle your purchase towards that).
There are also good savings to be made by changing your fridge/freezer and your washing machine to something more efficient (If you live in England we already have a rating service for these, buy only A rated things and you'll save - if not then you'll have to do some investigating on your own)
*''I can't believe it's not a hyperlink.''
I love my kill-a-watt but I've been thinking of picking up a Watt's Up? for the datalogging capabilities. But the price is silly, I should just build one.
Anyway, a clamp-on ammeter should be in your toolkit. (Get a DC-capable model and watch motherboard/peripheral power draw inside your PC!) Instead of slicing open an extension cord, consider an AC line splitter to make your measurements with. The 10-winding side makes small measurements more accurate, and it looks more professional if you end up using it on the job.
Every little bit helps.
I hate statements like this because they aren't logical. I'm not saying that it isn't logical to save energy, only that a shotgun approach is not the most logical method. If you want to save energy it would probably help to look at the items in your house that use significant amounts of power. While it may make you feel good to turn off a 40W light, it isn't going to make nearly as much difference compared to raising the temperature of your refrigerator, using your washing or drying machine less, using your microwave less, using your hairdryer less, using your oven less, or raising the temperature of your thermostat (or decreasing for the winter). Each of the latter is a KW magnitude device.
The best way to save energy is to prioritize. Work on thermal insulation and sealed windows will probably pay back twice the energy savings to what the energy nannies around the world recommending you turn off your lights, TV, and computer. The reason should be obvious for those with electrical heating: since electrical energy will eventually become thermal energy, does it make a damn bit of difference heating a home by electric heaters or by your TV, stereo, computer, and lights? Why limit them if your thermostat is at the same setting? Local effects? Then buy a fan (and the same argument still applies).
What would be the effect of limiting your lights, TV, and computer use if you have electrical heating? Your heating system would have to compensate and operate longer to reach the setpoint on the thermostat. In effect, if you live in a cold place there is no purpose to reduce other electrical loads unless they overcompensate for your heating. In a hot place, it makes sense to limit your other loads, but prioritizing will have a larger effect.
But since we are talking strictly about energy usage, household electrical power really is just a drop in a large bucket. Your car will be at least 200 KW thermal, and local industries will outpower residential electrical usage by over a 2 to 1 factor even in rural communities. I came from a town of 30,000 people. Residential areas used from 30-60 MW. One local mine used 50 MW (open pit mine with ore crusher). Another local silicon manufacturing plant used from 30-60 MW.
Every time a watt-hour (3600 Joules) is consumed, an LED blinks. What is your problem?
http://outcampaign.org/
For my house, A/C is by far the biggest chomper of energy. During the summer months my electric bill gets as high as $270, and during the winter it gets as low as $70. Not only that, but on hot (97 degrees f) days my upstairs never gets cooler than about 78f.
It's a fairly new house, so I can't simply replace the upstairs unit, but I think it's clear that they didn't install a large enough one. What can I do? Put another powered roof ventilator in? Add more insulation in the attic? Put a radiant barrier on the underside of my roof?
This website helps to answer these questions. It provides some analysis of the different scenarios. Dunno if the analysis is accurate or not...
Even if you do understand the above, don't try it. Oh sure, if you want to be nice to the power company, it will provide some useful information, but p(t) = v(t)*i(t) does not mean that P_av = V_av*I_av, or even P_rms = V_rms*I_rms unless voltage happens to be a linear function of current. (or vice versa.) In which case you don't even need to measure both.
If you don't know what you're doing, a real laboratory instrument will be much, much less accurate than an inexpensive device specifically intended as a power analyzer.
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