Electric Use Meter Advice

[Sanitary Stache]

I am embarking on a goal to track and budget my families carbon foot print in order to reduce it by 80% over the next year, and continue reductions year on year until I am a carbon sink rather than a carbon producer.

I want to measure my electricity usage and am going to start with broad strokes (the house meter) and hope to find ways to refine.  For instance, I want to know how much electricity the refrigerator uses.  I am looking for a simple kW/hr meter.  I imagine a product that live between the plug and the outlet, but I suspect (based on cursory internet searches) that there are more sophisticated options available. 

I don't want to spend much money on this, and I don't want to introduce a new electric load to do it. 

What should I be looking at?  Should I try to measure each high energy user individually, should I try to break it out based on my electric panel's circuits? Should I work with approximations instead of data?

Has anyone done this? Is there a blogger out there that is laying this out in an entertaining way?

the scope of my carbon foot print reduction is everything that is part of my life, so I anticipate expanding my data collection and analysis as the years go by.  If this process is similar to how I learned to budget and track money, I expect to be proficient at identifying and reducing my carbon foot print in about 3 years.

[NorCal]

There’s a couple routes you can choose at varying price points. I do recommend paying a bit more for a house energy monitor instead of just looking outlet by outlet. You’ll find some random things you wouldn’t find otherwise. For example, I learned that my Radon fan is one of the largest energy users in the house, and I can cut $40/yr from my electric bill by buying a more efficient model (pending more research on how much air I need the fan to move). I never would have figured this out with a kill-a-watt meter.

The Emporia power meters look good, and seem reasonably priced. I wanted one of these. However, I ended up with the Sense (more expensive), as my house has multiple sub-panels, and the Emporia doesn’t work well in that situation.

Kasa also makes smart plugs that measure power use. These are great for measuring single devices like a refrigerator. I also combine them with my Sense for other functionality. For example, I schedule some vampire load devices to turn off at night, and I get an alert if my sump pump ever turns on. These are a bit pricey at sticker price, but they do have frequent Sales on them at Amazon.

[uniwelder]

I won a kill-a-watt at a home show ten years ago. It plugs in directly at the wall outlet and measured electrical usage of a single device. As the previous poster mentioned, it’s limited in that many devices you’d care about can’t be measured this way, like your hvac blower or water heater, etc. It is great for the fridge or window AC or dehumidifier. I found out it costs me $0.50/day to run my dehumidifier in the basement. Wish it wasn’t necessary, but until some major waterproofing happens, that’s how it’s gotta be.

[bill1827]

I've been doing this for years, starting off with plugin energy meters and a whole house meter, then migrating to measuring every circuit.

I've used the early Arduino based Open Energy Monitor design, Brultech ECM1240s, a Brultech GEM (https://www.brultech.com/greeneye/) and Iotawatts (https://iotawatt.com/).

The OEM system is no longer produced, it has been replaced by a Raspberry Pi based unit which is better in some ways as it includes an Emoncms instance for logging and displaying data, but worse in that it only has 2 inputs; you can send data from other sources to the Emoncms instance though.

The Brultechs are good reliable monitors, but a bit pricy and needs additional resources for logging.

My favourite is the Iotawatt; it's relatively affordable and has 14 inputs. They store data on the Iotawatt but you can send the data to other loggers. It supports EmonCMS, InfluxDB and PVOutput.

All these systems will consume some power, but it's only a few watts.

Apparently the Emporia meter doesn't log locally but in the cloud. That's a big NO from me!

Logging per circuit is the best way to go, I think. It's quite easy to identify individual devices and check their consumption, if you have enough granularity in your circuits.

My system uses an Emonpi for logging incoming mains and running EmonCMS, a Brultech gem for monitoring individual circuits, 22 in this case. An Iotawatt monitoring 6 PV related sources and another remote Iotawatt monitoring 7 circuits in a pump house.

[Sanitary Stache]

The number of words I don't know in that reply is intimidating. I assume my house is much more simple that your system. 

I like the idea of monitoring each circuit to start. Thanks for the links and the words to learn.

[jeromedawg]

Definitely start with a kill-a-watt at least for the appliances/devices that are standard 3-prong and 2-prong. https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU

For measuring specific items that are on a circuit, I'm sure there are other brands out there but there is this: https://www.amazon.com/Emporia-Monitor-Circuit-Electricity-Metering/dp/B08G37ML2R - I would want to hire out the installation of something like this, however. 

[habanero]

I want to measure my electricity usage and am going to start with broad strokes (the house meter) and hope to find ways to refine.  For instance, I want to know how much electricity the refrigerator uses.  I am looking for a simple kW/hr meter.  I imagine a product that live between the plug and the outlet, but I suspect (based on cursory internet searches) that there are more sophisticated options available. 

As you are an engineer, engineer it. Make an educated assumption of the biggest consumers and check your assumptions. Dont know how you run your home but by far the biggest sources of energy consumption are heating / cooling - whichever is relevant and hot water. The rest is gonna be pretty minor in comparison. I live in an all-electric household in a cold climate and during winter my energy consumption is 3-5x what it is in the summer so it's not rocket science to figure out what the main use is.

For stuff that's plugged in constantly it's fairly simple - run a meter for a day or two and see what it is. Alternatively measure your entire household for say a week when noone is in there, that's a pretty good guesstimate for background consumption. It will most likely be fairly low. Repeat while you live there, the delta between the two is what your daily life consumes.

[secondcor521]

^ I thought electric clothes dryers and electric stoves were also fairly big users of electricity.

Some old desktop computers can be moderate users as well.  Newer ones with newer OS power saving features mostly address it.

[habanero]

^ I thought electric clothes dryers and electric stoves were also fairly big users of electricity.

Some old desktop computers can be moderate users as well.  Newer ones with newer OS power saving features mostly address it.

Yeah, but the being at home doing daily life vs not being at home gives a fairly decent data point for background vs active consumption. Also, energy use cases vary quite a bit from location to location. I live in a rather cold climate so say half of the year any energy use in the home finds use as heating, the alternative would in my case be heating with direct electricity so the energy usage during the cold months is of less relevance to us. If the house were devoid of stuff using electricity we would turn on the heat much earlier than is currently the case. This is one of my main beefs with electricity savings in places that predominatly use electricity as the energy source - you can pretty much discard usage in the cold months as it provides heating you need anyway. Even when it gets pretty freakin' cold outside our energy usage "only" doubles or triples, the rest of the year it's extra heat we don't need so wasteful, but in the winter months it has actual use as a heating source.

[NorCal]

So I installed my Sense home energy monitor in late June.  It's detected most of the devices in my household now, and I have pretty good data for September.  Here's the breakdown of my usage in September.  Note that we barely ran the AC at all this month, so HVAC is only a small piece of the equation.  Also note that the "Always On" load has overlap with other categories, so it doesn't sum to 100%.

-"Always On" devices:  23.2%
-Other: 22.9% (this is largely the bit of Air Conditioner we used, as Sense hasn't yet detected the AC)
-Refrigerator: 15.8%
-Radon Fan: 7.7%
-Hot Water Heater: 4.1% (we have a gas water heater, but this is the electricity for the electric power vent)
-Office Power strip: 3.7% (mostly the internet router, and a little bit for the printer)
-Dryer: 3.5%
-Chest Freezer: 3.3%
-Stove: 3.2%
-Desktop Computer: 3.1%
-TV: 2.3%
-Dishwasher: 2.2%
-Oven: 1.9%
-Coffee Maker: 1.4%
-Microwave: 0.8%
-Garage Lights: 0.6%
-Washing Machine: 0.6%
+ A bunch of smaller devices that use 0.1% or less

What surprised me is that there are some things like the dryer that use a TON of electricity while in use, but it doesn't add up to much over a month.  However, there are small things that are always-on that take up way more than I expected when you look at a long period of time. 

Now when I back into my full annual bill, I have a pretty solid breakdown of where the money goes.  This is broken out by dollars, and the hot water heater and furnace are gas.

Hot Water Heater: 24% (this is high because of an inefficient hot water recirculating system)
Furnace: 22%
Air Conditioning: 13%
Everything Else: 40% (this is essentially everything listed above)

This list is part of why I recommend the whole house monitor.  I have a really good idea of where all my money goes, and a lot of it is counter-intuitive.  I would have assumed that the AC was the biggest energy user, when it really isn't.  I'm now having someone out to take a look at the hot water heater, as I'll likely get my best returns on finding efficiencies there.

[yachi]

Hot Water Heater: 24% (this is high because of an inefficient hot water recirculating system)
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I'm now having someone out to take a look at the hot water heater, as I'll likely get my best returns on finding efficiencies there.

Have you evaluated how much water the recirculating system saves you?  I assume the alternative is to run your hot water sink or shower until it warms up.  Unless you have a massive house, I can't imagine it's more than a 5 minute wait at 1.5 gpm?  In my area of abundant low-cost water, a hot water recirculating loop with a pump is a cushy comfort so you don't have to wait, rather than an effective water-saving device.  Does it at least turn itself off at night?

[NorCal]

Hot Water Heater: 24% (this is high because of an inefficient hot water recirculating system)
.
.
.
I'm now having someone out to take a look at the hot water heater, as I'll likely get my best returns on finding efficiencies there.

Have you evaluated how much water the recirculating system saves you?  I assume the alternative is to run your hot water sink or shower until it warms up.  Unless you have a massive house, I can't imagine it's more than a 5 minute wait at 1.5 gpm?  In my area of abundant low-cost water, a hot water recirculating loop with a pump is a cushy comfort so you don't have to wait, rather than an effective water-saving device.  Does it at least turn itself off at night?

I made this discovery about a week ago, and I am actually having someone look at it today.

I've put the recirculator on a smart plug, and it's on a pretty tight schedule.  The problem is, hot water rises and cold water falls, so the system continues flowing even when the pump is off.  I've insulated the pipes I can, but that doesn't make a difference, as the majority of the pipes are in the walls.

There's a valve I can manually turn to stop the water flow, and I've used this with my energy monitor to confirm that about 50% of the energy use is due to the recirculating system.

When the system is deactivated, it is 3-4 minutes for hot water, but the hot water is much more tepid than when the system is on.  Enough so that a shower is uncomfortable.  Water usage is also a big thing here in Colorado.

There does need to be room for efficiencies here, but I've reached the limit of my DIY research, so it's time to have a professional to look at it.  Similar to the OP, I have a long-term plan to cut my carbon footprint.  I'd like to see if a high-efficiency hybrid system would be appropriate that I could offset with solar panels. 

I would love it if there was a valve I could install to stop the water flow, and put it on a timer.  I'm not aware of any such device on the market though.

[Sanitary Stache]

I would love it if there was a valve I could install to stop the water flow, and put it on a timer.  I'm not aware of any such device on the market though.

Part of bill1827's post makes me think they know how to do this with a solenoid valve. I wonder if one can be wired to a switch. Then you could have a timer and a manual override in a pretty simple package.

[brandon1827]

Something that you may be able to take advantage of (if your local power provider offers it) is a home energy audit. Many power companies have a person (or persons) who will come to your home free of charge and do an energy audit; which involves testing your meter for accuracy, doing infrared testing inside the home to locate any areas of loss, talking with you about ways to reduce your consumption, etc. I work at an electric cooperative and this is a service we provide our members. Many who are frustrated by seemingly not being able to adequately affect their bill by finding ways to lower their usage find the energy audit eye opening. So many things go into it; appliance usage, home insulation, windows, thermostat settings, heating/cooling unit efficiency, etc. that it may be able to help you achieve what you're trying to achieve.

[yachi]

Hot Water Heater: 24% (this is high because of an inefficient hot water recirculating system)
.
.
.
I'm now having someone out to take a look at the hot water heater, as I'll likely get my best returns on finding efficiencies there.

Have you evaluated how much water the recirculating system saves you?  I assume the alternative is to run your hot water sink or shower until it warms up.  Unless you have a massive house, I can't imagine it's more than a 5 minute wait at 1.5 gpm?  In my area of abundant low-cost water, a hot water recirculating loop with a pump is a cushy comfort so you don't have to wait, rather than an effective water-saving device.  Does it at least turn itself off at night?

I made this discovery about a week ago, and I am actually having someone look at it today.

I've put the recirculator on a smart plug, and it's on a pretty tight schedule.  The problem is, hot water rises and cold water falls, so the system continues flowing even when the pump is off.  I've insulated the pipes I can, but that doesn't make a difference, as the majority of the pipes are in the walls.

There's a valve I can manually turn to stop the water flow, and I've used this with my energy monitor to confirm that about 50% of the energy use is due to the recirculating system.

When the system is deactivated, it is 3-4 minutes for hot water, but the hot water is much more tepid than when the system is on.  Enough so that a shower is uncomfortable.  Water usage is also a big thing here in Colorado.

There does need to be room for efficiencies here, but I've reached the limit of my DIY research, so it's time to have a professional to look at it.  Similar to the OP, I have a long-term plan to cut my carbon footprint.  I'd like to see if a high-efficiency hybrid system would be appropriate that I could offset with solar panels. 

I would love it if there was a valve I could install to stop the water flow, and put it on a timer.  I'm not aware of any such device on the market though.

Timer-controlled solenoid valves could be used, but you would have to be very careful with how the valve is controlled.  You don't want the recirculation pump running against a closed valve.  The other thing that could improve the system is an aquastat to control the pump being on or off based on the temperature in the return line. 

The shower never getting up to temperature when the pump is off is concerning.  Here's a schematic of a typical hot water loop.  The pump is on the return line, and when the faucet is turned on, all the flow comes from the top of the tank through the mixing valve.  There's a check valve preventing it from coming the other way - there is a chance that check valve isn't working or isn't the correct type that would lead to some uncontrolled mixing of hot and cold water.  See a discussion here.