So, how much power do you have to save with a Kill-A-Watt to offset the impact of creating the meter?

It would be fun to try it out on a bunch of things,
(like answering my question about cost of storing stuff on top of the refrigerator),
but I haven't found anyplace near me that has them for loan,
and the idea of getting a gizmo that will be used a few times and then
spend most of it's life in a drawer leaves me cold.

He, tricky and interesting question....

I think it depends.

A good thing about Kill-A-Watt, is it can change a persons focus. And that's probably the main thing, because if people get more focused on saving the environment, we actually achieve an important thing.

On a more practical, it also depends. If the Kill-A-Watt investigations in your house, find a freezer with abnormal power consumption, then the Kill-A-Watt served it's purpose. In my case, I do have a very old freezer, and I was setteled for upgrading. But my Kill-A-Watt, showed this freezer got a significant lower power consumption, than its rating. Thus I didnt abused the environment, by buying a new freezer.

Just share it around. I've had over 20 people borrow my watt meter, I'm sure its saved more than it cost.

The thing is a simple tool, like all others. How much value you get out of it, depends on how much you use it, what sort of problems it solves, and the amount of money/time it saves.

Use it once and throw it in a drawer.... and it's probably not worth the cost.

I agree with dragmor. I have one and have used it quite a bit. The more people you pass it around to though the greater its impact. Surely if it even changes one persons outlook on power consumption than it is worth the manufacturing cost (both environmental and economic).

Thanks to my eye-opener I save 400 kWh per year at home, and 3000 kWh at my job. That's almost 750 euros over here and around 2200 kg of CO2. It was a major factor on my route to energy enlightenment.

I noticed that the Ottawa Public Library has a bunch of these available for people to borrow. There's probably others doing that as well.

That's one way to keep the impact low!

I find it commendable that you would take such a minute tool as a Kill-A-Watt into the overall environmental equation, really, yet I cant help but feel it’s a bit contra productive since you might just end up needing that very same tool in order to establish the power draw of various components and products.

Cheers

These meters are useful for more than just one-time power surveys.

For instance, if you leave one in-line with your computer's AC cord after measuring typical idle/load wattage figures, it can serve as a sort of load-level indicator, showing at a glance how busy the system is, whether you might have left a background process running inadvertently that's hogging a lot of CPU time (and power), etc. It will show exactly how much energy is saved through various software changes, like AMD Cool'n'Quiet or Intel Speedstep, enabling the various ACPI sleep/idle modes, or even installing a Flash-blocking browser plugin (background Flash animations can hog a surprisingly large amount of power... I like the FlashBlock option for Firefox that runs them only when clicked on).

I have a Kill-a-Watt semi-permanently attached to the AC->DC supply feeding my 12V battery system. It's kinda neat watching it gradually fall down to zero as the sun comes up, and solar panels take up an increasing proportion of the DC load.

I still haven't found an answer to the question I posed initially, but have found a site that might be working towards an answer. (Or at least where an answer should be.)

Wattzon is a project to generate a database of embodied energy in various devices.

http://www.wattzon.com

Further question: If, as some suggested here, one leaves a Kill-A-Watt in circuit for long term monitoring, how much power does the Kill-A-Watt meter use itself?

I realize that it probably isn't much (probably have to use it a long time to come close to the amount of embodied energy). Partially this is a matter of principle. If the purpose is to change focus, "go green", environmentalism, then that focus/education/view should reasonably encompass the impact of the tools and efforts used in an effort towards reducing impact. So products touting greenness should be up front about their energy use (both embodied and while they are in use), as well as materials, lifespan, etc.

Thus, systems like tweet a watt, google power meter, etc. should include information about how much energy the monitoring itself takes.

Another example: Makers and reviewers of these supposedly green surge protectors which switch off other outlets by monitoring the state of one device should be up front about the costs of these devices. Most of them don't point out that the switching/sensing circuit introduces a standby (vampire) load (in addition to that of the master device). A plain old power strip uses less energy (when it is off, everything is off). (The ones that sense one device and turn off the rest have place - for convenience, or where the users won't use a switch. But should be up front about the downsides.)

Depends. A single watt saved could suffice, if it is from a device that is on 24/7 and will be kept a long time. Say you find out that your intercom is using unnecessary idle power. And there's an easy fix for that. If that intercom were to be in use for 20 years (independ of who lives there), then that's 175kW of unnecessary power. It will most definitely not need 175kW to produce a Kill-A-Watt. As such, your purchase would have paid off even if you'd never use it again.

But I don't know mate, I think you're reaching a paranoid stage of greeness.

Kill-A-Watts are mass-produced, as such, technically speaking, the more of them are produced, the smaller the CO2-footprint of a single individual unit, because the vast majority of energy is used by the factory.
Also, the impact of you personally not buying one is so irrelevant, that it wouldn't matter anyway. The manufacturer is not gonna "notice" that and will produce one less.

Now, if you'd convince thousands of people to not buy Kill-A-Watts because of their potential CO2-footprint, it would have a bad impact because if just a handful of these people would save a few dozen watts after checking their consumption, the accumulated impact over years of saving will be much greater than that little bit of CO2-footprint a few thousand Kill-A-Watts have.

And, most importantly: people have to make a living. If too many people stop buying a certain product, the manufacturer will stop producing it. But he and the people he once employed still have to earn their livelihood, so they have to find other jobs. To be really sure, you would need to calculate the probability that the new jobs they're getting have less environmental impact than their jobs at the Kill-A-Watt factory.

To sum it up: just buy one.

If you use the Kill-A-Watt to save power, then great! After you are done with it -- pass it along to a friend, or pass it around at your church/club/family; or donate it to the local technology teacher (at high school, or college), or even the local library might be interested in loaning it out to the community.

We gotta' start saving a lot of energy, and we have to start somewhere. If we talk ourselves out of trying to solve problems before we even start, then we are guaranteed to fail.

Reasonable point. Around here the power savings would have to be a little more to make it pay for itself (monetarily), but still as you say they don't have to be huge if you allow a long enough time.

It would be interesting to find out how much a "typical" or average user of a Kill-A-Watt meter saves in the medium to long term. (i.e., after the initial fever of testing things or turning things off.)



"Just because I'm paranoid doesn't mean they aren't out to get me"



The energy used by the factory is part of the embodied energy (along with that used in making the parts and packaging, shipping the parts and the final device, warehousing, marketing it, recycling, etc.). One may be able to improve efficiency, but you can't make it go to zero unless you stop making them.



Of course that is illogical - by that reasoning, one shouldn't vote, and likewise by that reasoning beaches contain no sand. (if I take away one grain of sand, it is still a beach. Therefore I can repeat that operation, and still have a beach. There are only finitely many grains of sand on a beach. Therefore after removing all the sand I still have a beach.)

(Actually, I would just as soon anybody who is swayed by that reasoning doesn't vote - since that means that the people who understand the flaws in that argument will have more influince.

Nobody made a greater mistake than he who did nothing
because he could only do a little.
-Edmund Burke

Consider also Superrationality - people may think like me and act like me, whether I communicate with them or not.
http://en.wikipedia.org/wiki/Superrationality

And of course gathering information is an early step towards influencing.



Not buying the meters does not preclude using them. If we persuade thousands of people to borrow one of the meters instead of buying it, then not only have they saved energy (assuming that use of a Kill-A-Watt results in energy savings for the average user - which seems a reasonable assumption, but worth checking), but we have also cut down on energy to create those meters, reduced clutter of gadgets in their homes, reduced the need to recycle the meters eventually, and the users will recoup their investment even faster because they don't have to recoup the full cost of the meter.



Speaking of paranoia.

We've been saving energy for a long time. Had florescent lights in our house since the 60s. Ditto additional insulation. Never had AC. ...

But interesting to see new options, etc.

(Actually I did buy a Kill-A-Watt a few months ago (after asking around at the local public utility, library, tool library, environmental groups, etc., and not finding anyplace to borrow one), finally now the city library to make a bunch available for loan. Waited a long time - just didn't wait long enough. C'est la vie.)

Been thinking that putting together a website listing the places one can borrow a wattmeter (arranged by geographic area) might be a useful/handy resource.

Better yet, we should push to have our electricity meters replaced (during the routine maintenance) with units that relay the info to a meter on the inside of the house (or on our computer) so that we can see ALL the use and cost, etc. This will help us track down the hidden/phantom consumption, like door bell transformers, etc.

Smartmeters are coming to my neighborhood in the next few weeks via PG&E. So, I will be able to track use by time of day via their website. Should be interesting. Don't know if it'll reveal anything wild.

Smartmeters are a nice tool to see the consumption averaged over time, but without per-circuit monitoring it will only do so much. A kill-a-watt will give you both instant and average power usage readings on a device, which can then be used to calculate cost in a meaningful manner.

I would say that the potential savings in using a kill-a-watt to properly survey what uses too much power in your house easily offsets the power used to create the meter, and when you're done with it, why dont you lend it out to friends who also needs one? That way you reduce the footprint even more.

I don't know - unfortunately that is fairly similar to the "smart" meter systems which various utilities are trying, and which sound really nasty from a reliability and security standpoint.

Replacing something simple and reliable (electro-mechanical electricity meters do not need replacement often, designs have been well tested), with something complicated (and therefore subject to problems).

"There are two ways to construct a software design.
One is to make it so simple that there are obviously no deficiencies,
the other is to make it so complicated that there are no obvious deficiencies."
-C.A.R. Hoare

Electronic meters would probably involve more toxic substances than the old mechanical meters. Might also be harder to recycle?
How is the lifetime on the electronic meters - do they last as long? Longer? (Also have all the overhead for the communications, the in home display, the data centers, etc. vs. the overhead of meter reader. Are the impact of all those taken into account when figuring the "savings?")

More potential for monitoring/invasion of privacy. (e.g., Those with access to the feed can get pretty good idea of when people are at home, when they aren't, and can potentially do for whole neighborhoods. Would be great for burglars. Hopefully such information would be encrypted, hope it holds up better to crackers than some of the other encryption schemes, and that the encryption is field upgradeable but only over a secure medium, so that when it is cracked they can fix it, rather than having to wait decades until they replace the meters again, or letting anybody who can crack the encryption reprogram your meter.)

Looks like (as often happens with computer systems) they are trying to make the meters fancy, and therefor they have big problems. (Which will become our big problems.)
http://www.theregister.co.uk/2010/01/15 ... ypto_flaw/
http://www.theregister.co.uk/2009/06/12 ... ity_risks/

(Just like voting machines, web browsers/botnets, etc. - yuck!)


I can see where it could be interesting to have a readout on electricity use. But for folks who are already pretty careful about their energy use I wonder how much difference it would make. (Law of diminishing returns.)

After you get past the initial coolness phase - is it just one more blinking electric readout around. How would one use a whole house display to help change usage habits? (Did they test them long enough to see about lasting changes - or is it just a temporary thing.)


An idea I have been toying with is a thermostat that would show you the cost ($), greenhouse gas emissions and amount of fuel used (oil, gas, etc.). If you change the thermostat setting it would display an estimate of how much the change will cost (in the above metrics). (Rather like the current gas mileage display that some automobiles now have. Or like having your mother automatically say "oil costs money, put on a sweater.") Giving immediate feedback when one is making an energy use decision might be helpful in shaping that decision.

With a whole house usage display it isn't as clear how one would use it to help change behavior (any more than the usual looking at the little graph on the electric bill and seeing how usage is going.)

Digital meters are already the standard. They communicate with the electric company digitally via the power lines. No meter reader comes to your house.

I understand your concerns -- believe me I do. I just think you are being myopic by focusing on the very things that would help us consumers try to control our run away energy use. Heating and cooling are by far bigger energy consumers. Transportation, food production, water use, are all miles more important than the odd electronic device that measures electricity use. Cell phones, televisions, DVD players, electronic games, computers, even greeting cards, probably swamp the embedded energy in a Kill-A-Watt. And if the house meter gets replaced anyway, then were is the harm of using it to educate the consumer?

A couple of other comm methods exists:
- low power rf in a mesh network to an aggregator. Then backhauled to the power company. (PG&E uses this in subdivisions)
- A variant of Wifi to an aggregator.

I'm not sure what Silicon Valley Power is going to use, but it will come with free wifi for all living in Santa Clara.

Wibla - my trusty kill-a-watt has been very helpful. I've cut my electric bill by 40-50% by finding gross users (old fridge = ugly) as well as understanding which devices have great idle/standby power and which don't.