Efergy E2 Energy Monitor

I recently received the below email from Lyn Chapman of Chapman Specialty Equipment & Inspection.  It seems that the Efergy E2 is made by a U.K. company and Lyn is based in Ontario, so I'm not sure how it would perform in the U.S., but it definitely looks like a good product has the potential to be a good product (see my update below for clarification).


I was asked to conduct an independent evaluation of energy monitoring products for my company. I looked at numerous products and purchased the Black and Decker whole house Energy Monitor (which uses the same technology as the Energy Owl) , the TED 5000, and the Efergy E2. Here in Ontario we quickly found ourselves dead in the water with the Black & Decker unit as the majority of meters used by the various utilities are not compatible with the technology utilized for the device.

The TED 5000 is a good product but we found issues with the powerline communication system used with the devices. This required us to come up with solutions to make it work which included spending additional money on noise filters, installing dedicated breakers for the MTU's and locating the gateway close to the utility panel.  We then encountered the expense of running cable to the modem from the gateway location and this also limited the communication range of the remote monitor.  On the issue of the remote monitor, the first one sent to us was defective and would not work at all.  While the replacement monitor does work, it does not communicate everywhere in the building that we would like.  We were also unable to get the Google Earth feature to work.  TED support advised us that their Google Earth feature is not supported by all ISP's in Canada so we would have to sort that out with our individual ISP. In Ontario, the TED 5000 units have to be installed with a permit and then inspected by the Electrical Safety Authority, all at additional expense.  While we landed our TED 5000 with 4 pairs of Ct's and the remote monitor here for around $520.00,  by the time we had it installed and working,  we were over $1200. deep.

The Efergy E2 is also a good product and we found that it was capable of doing everything we needed including the collection of historical data and making graphs. The unit was quick and easy to  program, easy to install, and the wireless radio communication worked flawlessly. There was nothing else to buy, no permit to purchase, no electrical contractor to involve, just 30 minutes of my time and we were in business. We now have over 40 of the E2 units in service at our various client locations, all without a single glitch.  We have been purchasing our units from a company in Florida  at

It is worthy of note that I was on a training course with Schneider Electric in Toronto a few months ago and an Engineer in the class from New York was expressing his concerns to me over the communication problems he had been experiencing with his Energy Detective. I told him about our experience with the Efergy.  After returning to the United States, he purchased and installed four E2's from Florida for his own use and that of his family. He has been absolutely delighted with the Efergy E2's he purchased.

I am advising you of this information as I believe that you would do your readers a great service by including the Efergy E2 in your product line up of energy monitors. These are difficult economic times and the Efergy E2 sells for about half the price of an Energy Detective. When it comes to monitoring energy, the E2 does a fantastic job.  I typically install an E2 in our client locations in less than 30 minutes including programming.  The Efergy E2 is also available for 3 phase installations.


***Updated - 4/17/10 - I had a reader write me with the following comment: "I looked up the install info for the Elite and Elite 2 Efergy systems. They don't have a voltage connection and therefore do not sense voltage. Voltage is entered in the display. These are really current meters that don't measure kw or even volt X amps. The accuracy will be very bad with motor and transformer loads. Also inaccurate with voltage changes. The TED and also the ECM-1240 family (Brultech) are true kWh monitors."

And it seems that he is right.  I found the install instructions on Efergy's website here.  The instructions state:


Press and hold Mode Button for two seconds. Default voltage is set at 240V. Use BWD and FWD buttons to change the voltage. Press MODE Button to save your setting and move into currency selection setting.

And so if your voltage never varies, you will have accurate power consumption data, but if your voltage does have a problem.  How does the Efergy unit differentiate between 240 V loads and 120 V loads?  For example, most U.S. homes have both.  Your toaster or TV runs on 120 V, but most electric clothes dryers and AC units run on 240 V loads.  If you have to manually enter voltage into the Efergy unit, how can it determine total power consumption if you have your AC unit (240 V) and your TV (120 V) operating at the same time?  The Efergy unit will read total current flowing through your wires, but the total power consumption it tells you will either be too high (if you entered 240 V into the unit) or too low (if you entered 120 V into the unit).

***Update - 9/3/10 - My original issue was solved, so I crossed out the text, but it is important to note that in U.S. installations, you must set voltage to 120-130 V!

***Update - 4/28/10 - Thanks to the help from Lyn and Juan from Energy Monitoring Technologies I have the Efergy InstallationSupplement-US & Canada.  In US installations, the Efergy unit uses 2 current transformers to measure current on both legs of the residential electrical service.  When a 240 V load is operating, it is merely pulling power from each of the 120V leg and adding the current from those two lines together in its logic.  For instance, your 240 V appliance may see 5 Amps at 240 V (1.2 kW) , but the Efergy meter will be recording two, 120V/5A loads (120*5 + 120*5 = 1.2 kW).  For all intensive purposes, it doesn't matter if a meter measures 4 Amps at 120 V or 2 Amps at 240 V, the math will come out the same.

But conservation isn't the only area where  a problem can occur.  Clean energy installations could also pose an issue.  The voltage on a solar panel array will fluctuate throughout the day based on how the inverter regulates the Maximum Power Point.  Basically, the inverter will fluctuate the solar array's voltage output so the power is alway at its maximum.  If the voltage fluctuates, the Efergy unit is going to be unreliable!

***Update - 4/20/10 - Thanks to some helpful comments below (thanks Lyn, Suzi, Juan, others) I'm not so worried about the accuracy of the Efergy meter, but I would like to hear about people who have tested the Efergy's accuracy against their residential meter or used it to monitor a solar panel installation.  See Lyn's comments below about where he sets his voltage setting at.

enjoyed our post? let others know: 


Dear Sir: Could you please send a quote for the Efergy e2 to be used in a 3 phase 380VAC 60Hz to me. Please include all charges for transportation to my address in Chile. Thank you very much, LEANDRO
As the Efergy E2 was designed for single phase two wire installations that are the norm in the UK, one has to understand the American electrical system. In the UK, the e2 would only need one CT, as all of the power would come through the single power wire, and flow back through the neutral. At any one point on the wire, you can meter the actual current. In the US, most houses have two power wires and a neutral. Power can come from either leg, and flow back through the neutral, or flow back through the other leg in the event of a 240V device. This is called Split Phase. A single CT cannot measure this power source. For US installations, two CTs are required. Any power that does not flow through one will flow through the other. However, it is important to set the voltage to 120V. The more sophisticated energy meters such as the Shark 200 units, which we have installed for commercial clients, are utility grade, highly accurate and gather a wide range of data such as power factor, power quality and reactive power. They are directly connected to the supply to gather the actual voltage readings. This level of data is not important for consumers. If you live in a developing country where voltage levels are all over the place, you probably won't get as accurate measurements but for for the US and most places, the measurements will be as accurate as any consumer needs, and at a fraction of the cost of utility grade devices. One issue to be aware of, though - if you are using the meter to measure a single load at 240V, you need only one CT and should set the voltage to 240V. If you need to mount the unit at the meter base outside, use a weatherproof plastic box for the transmitter as this will not interfere with the wireless signal. This setup will give you a range of at least 50 feet. As far as needing a permit, I would think that permits are for "electrical connections" made in a panel. As the CTs are not electrically connected to the supply, there is no electrical work being performed and so no permit is required. If you do have a grid interactive renewable energy source such as solar, this meter will not netmeter and so will be inaccurate. Current flowing in both directions will be seen as consumption. I would wait on the next version which will be netmetering capable.
Chris, for US installations the Efergy does come with two CTs.
Hi All, Any idea how big is the Canadian Energy monitor market.
I found this note at the bottom of a product info page on a site that it selling the E2: "NOTE: This unit includes two transformers clips so you can monitor 110/120 and 220/240 volt units. You can also have a three phase unit with three transformers." I'm not sure if this addresses the concern in the update above, but it might. I live in Tempe, AZ and I also was unable to use the Black & Decker Power Monitor due to incompatibility with my meter, which is less than 1 year old and "smart". My utility is Salt River Project, or SRP. I'm hesitant to spend >$200 for the TED 5000, so I'm eager to hear more about the E2.
Chris, we are the manufacture of the PowerCost Monitor by Blue Line Innovations and the Power Monitor by Black & Decker. I just wanted to clarify your comment regarding compatibility of the Black & Decker Power Monitor in Ontario. Both of these products use a universal passive optical sensor attached to the outside of the electricity meter to acquire the data. The sensor is indeed compatible with older electromechanical/disk meters as well as new digital/smart meters. Overall these products are compatible with approximately 90% of all homes in North America. The one notable incompatible meter is the Landis+Gyr Focus meter as this meter turns its signal off after 24 hours of use. In Ontario specifically due to the presence of the Landis+Gyr Focus meter compatibility drops to approximately 70% of all homes in Ontario. For a complete listing of meter compatibility please see The PowerCost Monitor is now available at The Source and the Power Monitor by Black & Decker is avaiable at Canadian Tire. Thanks for your interest in this category of energy monitoring products. Sincerely; Peter Porteous CEO Blue Line Innovations
Suzi, can you please clarify one of your comments. You said no electrical permits were required but the Efergy appears to connect inside the breaker panel. In my community any work in a breaker panel requires a certified electrician. Is this correct? Thanks. J.S.
Hi Derek: Perhaps I can provide some assistance to you as I am the technical support rep for Energy Monitoring Systems Canada. You have a complete misunderstanding as to how the Efergy connects to the utility suppy and how it works. All Efergy products use current transformers (sensors) that clamp around the main supply conductors within your home or apartment. Typically, this would be the #3AWG conductors for a 100 amp service or 3/0 AWG conductors for a 200 amp service that go to the main breaker or disconnect for your service panel inside. For the record, this is exactly the same method used by the Energy Detective. With the Efergy, unlike the TED 5000 there are no MTU's to connect to breakers, no powerline communication issues, and no electrical permit is required. (Except in Australia) Best of all, if you have a service panel in a finished area in your home or apartment, you can just leave the Efergy transmitter inside the service panel and put the cover back on. Since the efergy meter is wireless, and uses burst communication values, there can be up to 30 units taking independent readings inside a single apartment building utility distribution room. The Efergy receiver is also portable, so the customer can take the meter in their hand throughout their home or apartment to see what different things consume by switching them on and off. A full array of historical data is also collected and can be analysed using the powerful graphing software that is included with each Efergy E2. The TED is a good product which I have installed, used, and studied myself. The Efergy E2 is an amazing product that works first time, everytime, without communication issues and sells for about half the price of a TED. During these difficult economic times, bang for buck, my money is on the E2. Should you have any further questions, please do not hesitate to contact me directly. Sincerely, Suzi Beck You may also wish to look at some of our recent customer testimonials with regards to the efergy E2 and energy saving tips at
So the Efergy system connects to a meter wire. From my own experience, I could not use this product in my apartment in California (no access to meter), or at my previous home in Ontario, Canada (no wires off the meter, slapped right onto a brick wall on side of house. Is the transmitter weather-proof? It would have to survive snow and rain at my previous residence, and survive neighbourhood kids just grabbing it and running off with it. For businesses with a meter in a better location, I could see it working better. The monitor also appears to have a USB connection to upload data, no web interface/dedicated server. (I may be wrong, haven't fully checked out their whole webpage for other possible options) If I had the choice, I'd still go with the TED5000 if I were to move back up there. I have no electical experience, but I was able to install the TED in my apartment circuit panel in under 10 minutes. I like the monitor box on my kitchen counter, but rarely view it. Since the Google PowerMeter feature, I haven't used TED's internal web server either. I get weekly emails from Google with my usage, which is so pretty :) What is the Google Earth stuff about, never saw anything needed from Google Earth to get it working. (something else I've missed in recent firmware??)
Hi Guys, I am writing from efergy the manufacturer of the e2. Firstly, Thanks Chris for the initial article, you are doing a great job in helping us raise awareness across the pond. It’s a great, well written article. Secondly, it’s great to see so many people taking interest in the e2. It’s a really good thread on here. If there is any more information that anybody needs on any of our products then don’t fail to contact us.


Post new comment

Subscribe to Comments for "Efergy E2 Energy Monitor"