Do You Really Need a Home Energy Monitor?

Nov 23, 2023

Whole-home energy monitors can potentially measure how much electricity your home uses down to the individual circuits and even single devices, thus allowing you to identify ways to save. With electricity rates rising nationwide and climate change driving conversations about consumption, efficiency, and how people get their energy, these monitors have appeal. According to the manufacturers and some of the independent experts we spoke with, many households save an average of nearly 10% on their power bills in the year after installing a monitor, with more engaged people saving up to twice that.

So why, after planning to test these monitors and make a recommendation, did we come away questioning their overall value for our readers? It's not because they don't work—we identified three models that we’d suggest to anyone going forward with a purchase. It's because they may not be necessary. That finding felt like the most urgent information for us to convey. Our conclusion became apparent as source after source outlined simple, tried-and-true steps anyone can take to lower electricity bills without the use of an energy monitor. It came into greater focus as sources emphasized how smart devices, often capable of reporting and limiting their own energy use, could integrate with Amazon Alexa, Apple HomeKit, or Google Home to form their own suite of information for both active and automated energy management. With smart tech integrating into more devices and even into circuit breaker panels, energy monitors may become a thing of the past. Here, we aim to help you determine whether a monitor or other energy-saving technology is your better choice today.

Sense, one of the earliest monitors available, uses machine learning to identify individual appliances and their electricity usage.

Sense's monitors employ machine learning—and a million measurements per second—to try to identify individual appliances and their power draw, teasing out their unique "signatures" from your home's main power feeds. The version that we’d suggest anyone consider first is the company's base model, but Sense also offers two upgrades, one that adds the ability to measure solar-panel output (if you have panels, of course) and another that can directly monitor two sub-circuits, "perfect for large loads, like HVAC systems and EV chargers or hard-to-detect variable motors, like heat pumps," as the company's marketing language says. The aim of the machine learning is simple: Although your utility company can tell you how much electricity you use each month, a monitor can give you more granular data on where your electricity is being used, potentially allowing you to identify areas where you can be more efficient (the data comes to you via smartphone and web apps). Sense told us that its customers realize an average savings of roughly 10% in the year after the monitor is installed, with active users often seeing 20%; these figures are in line with what we heard from the makers of other monitors we investigated. But machine learning is very difficult to implement well—which Sense was open about—and though most customers rate the company's monitors highly, about 15% report that even after lengthy use, their monitor hasn't been able to ID many devices.

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Generac's PWRview W2 monitor, based on the earlier Neurio W1, also uses machine learning to identify devices, and it costs less than the Sense.

*At the time of publishing, the price was $190.

Generac's PWRview W2 machine-learning monitor is based on the earlier W1 from Neurio, another pioneer in the field that Generac acquired in 2019. Generac gave savings estimates similar to those that Sense provided when we spoke, again pointing to active users’ ability to cut their bills by as much as 20%. Also like the Sense monitors, the PWRview is agnostic—it can work in almost any electrical panel. And it usually costs less than the Sense devices. As part of Generac's broader green-energy ecosystem, which includes solar panels and solar-storage batteries, the PWRview may offer the most advantages to people who already use Generac products.

Emporia's Gen 2 Vue monitor doesn't employ machine learning, but you can add extra sensors to directly measure what up to 16 individual circuits are using.

Unlike the other monitors we’d suggest, Emporia Energy's Gen 2 Vue monitor doesn't use machine learning to identify individual electrical loads, instead relying on owner interaction to identify individual loads and potential areas for saving: You can switch devices on and off while watching the monitor's real-time load measurements, or you can use the Vue app's integrations with various smart plugs, thermostats, and lighting to see how much power they use. That approach may appeal to you, and the company also offers upgraded models (or the equivalent retrofits) that add eight or 16 circuit-level sensors so that you can directly see what each circuit in your home is using on top of how much power is being drawn off your mains.

Sense, one of the earliest monitors available, uses machine learning to identify individual appliances and their electricity usage.

Generac's PWRview W2 monitor, based on the earlier Neurio W1, also uses machine learning to identify devices, and it costs less than the Sense.

*At the time of publishing, the price was $190.

Emporia's Gen 2 Vue monitor doesn't employ machine learning, but you can add extra sensors to directly measure what up to 16 individual circuits are using.

To write this guide, we relied on the expertise of others as well as our healthy skepticism of the value of these devices—a skepticism that has gained nuance but hasn't changed. We spoke with senior executives and product managers at three leading monitor manufacturers, conversed with three senior researchers at the National Renewable Energy Laboratory and the Pacific Northwest National Laboratory who have studied energy monitors, and talked with the founder of the respected energy-tech clearinghouse EnergySage and a writer there who has evaluated many of these devices. We also read as many of the academic or otherwise independent studies of energy monitors as we could find. Wirecutter's smart-home writers and editors provided valuable knowledge and insights into the energy-monitoring capabilities of many other electronics we recommend, and our information-security experts reviewed these devices’ policies regarding personal data protection.

All of that research gave us a well-informed foundation for analysis of this field. If we are able to conclude our long-term testing of any of these devices—with seasonal variability, it takes more than a full year to truly measure whether and how a given monitor can make a difference—we’ll update this guide with our findings.

Whole-home energy monitors are small devices that are installed in the circuit breaker panel of a house or apartment and intended to provide what's called load disaggregation: They aim to trace, via current transformers attached to your electrical mains, which devices in your home are drawing power and how much they’re drawing. They can then provide more granular information on a household's energy consumption than a typical monthly electricity bill offers. Your power utility may simply tell you how much electricity you used over the month, or it may offer a rough breakdown or localized comparison of your usage and some suggestions for how to reduce it. By contrast, a whole-home energy monitor can, in theory, help you identify individual appliances and optimize their performance, reduce or eliminate so-called vampire loads (devices that consume high amounts of electricity even when they’re "off"), and find devices that you may have forgotten were running. "Discovering the overlooked space heater in the basement" is a trope in energy-monitor marketing. As is "Your mileage may vary."

The goal, and it's a worthy one, is to help you save on your electricity use and cost. And the energy-monitor manufacturers we spoke to—Sense, Generac (with its PWRview), and Emporia (with its Gen 2 Vue)—were convincing and consistent in their claims of savings. A typical customer, according to the companies’ data, will save between 7% and 10% on their energy bill in the year after installing a monitor, and some will save twice that.

What's unclear is whether a given monitor is crucial to the savings. Some of the savings the monitor manufacturers gave as examples came from simply identifying and rectifying obvious inefficiencies, like finding the proverbial space heater or shutting off a light bulb that had been left on, unnoticed, in the attic. Maximum savings, according to the manufacturers, was tied to having solar power, an electric vehicle, and a utility that applies time-of-use rates (meaning, you pay more per kilowatt during peak-demand hours, rather than a flat rate), as well as taking advantage of those circumstances to maximize savings by using excess solar power in the home and charging the EV from the solar panels when the utility's time-of-use rates were unfavorable. In addition, the independent experts and manufacturers we interviewed all said that the highest savings are likely to be realized by the most engaged users, "the person that's kind of a tinkerer, that wants to know more about their energy use and wants to do something about it," in Pacific Northwest National Laboratory senior researcher Josh Butzbaugh's words. If that doesn't describe you—if you suspect that you’d be more annoyed than motivated by a device that's constantly sending you data and suggestions—you’re unlikely to get the most out of an energy monitor.

Experts we interviewed all emphasized two other keys to maximizing savings: making permanent behavioral changes (like being better about fully shutting off devices by unplugging them or shutting off the power strip or smart plug they’re connected to) and, even more effective and reliable, taking advantage of smart devices to make your behavioral changes automatic and permanent (such as scheduling your water heater to shut down in the middle of the day and overnight, when the need for hot water is likely to be low). Upgrading your old appliances to more efficient ones, like replacing an aging HVAC system with a heat pump, and taking simple and inexpensive weatherization steps, like sealing your windows, can also deliver big permanent savings, and your energy utility may help pay for them, said Butzbaugh and fellow PNNL senior researcher Ebony Mayhorn. (Check with your electricity provider; these programs vary, but eligibility is often tied to income.)

That's the big question. And the answer, in a word, is no. Simply being more mindful of energy wastefulness can help you cut your bill. Do you really need a push notification to shut the lights off when you leave a room?

One of our most convincing (if unsurprising) findings: Just a few investments in smart technology can make a huge difference. In one of the broadest studies we looked at (PDF), conducted by Lockheed Martin Energy for the New York State Energy Research and Development Authority, 50 homes were equipped with whole-home energy monitors (aka home energy monitoring systems, or HEMS, in the industry terminology). The conclusion was that investing in three smart technologies should produce the lion's share of annual energy savings; smart thermostats were named as the most impactful by far, followed by smart outlets or plugs and smart LED light bulbs or light switches. (The links go to Wirecutter guides to those topics, if you’d like to read more about how those technologies can help you save on energy. For advice on how to maximize their savings potential, see our advice on how to choose between smart switches, outlets, and bulbs and how to use smart lighting better. We’ve also covered the singular efficiency potential of smart thermostats, too, but we wouldn't be Wirecutter if we hadn't raised a serious eyebrow and identified exceptions. And though heat pumps are not simple or inexpensive upgrades, the extraordinary promise of heat pumps for HVAC efficiency can't be overstated—staff writer Thom Dunn dove deep.)

The NYSERDA study suggests that you can get up to a 16% annual energy reduction by installing smart thermostats, outlets, and lighting together. The common denominator is automation: Because these things can cycle off, according to a schedule, when they’re not needed or can shut themselves off when a room is unoccupied, the savings are not dependent on you or your housemates adjusting your daily behavior. Keith Marett, Generac's president of clean energy services, echoed the NYSERDA study when he told us, "This is exactly what we see in the data. The biggest thing people should be looking at is their thermostat. If they have an old, dumb thermostat, replace it with a smart thermostat."

Relying on an energy monitor to identify potential savings, by contrast, means consistently engaging with it. The available evidence shows that owners don't do so for long, and that much of the savings can be attributed to the most active users—a point that both the manufacturers and the independent experts we spoke with agreed on.

Shawn McLaughlin, founder and CEO of Emporia Energy, which makes the Gen 2 Vue monitor, said, "The novelty of the product, staring at that data, has some short-term benefits to behavior, but we believe that at about the three-month mark it starts to wane. The activity, the engagement with the app, starts to go down."

Mike Phillips, co-founder and CEO of Sense, described and shared several studies backing up the savings claim of roughly 7% to 10% but added that "what's really underlying that is the people that really use the app to actively look for savings get about twice that, but only about half of the people do it."

Bethany Sparn, a senior researcher at the National Renewable Energy Laboratory who has been looking at energy monitors since 2010, said, "I’m a huge energy geek, and I still don't know that I have time to sit around and look at my data." She later added, "There's been lots of studies where people responded to feedback, changed their behavior, but it's not persistent. It's just too easy to fall back into the patterns that you’re most comfortable with. That's why you were in those patterns to begin with."

In various ways, Keith Marett of Generac and Ebony Mayhorn and Josh Butzbaugh, senior researchers at the Pacific Northwest National Laboratory, expressed the same concerns: that energy monitors enjoy a short "honeymoon" when first installed, followed by a dropoff in owner interest, and that the sheer amount of data these monitors produce can be paralyzing. (As Sense's Phillips noted: "What we’ve found is that the more data you give a consumer, the more confusing it gets for them. It's more about the insights that you give the homeowner.")

Energy-monitor manufacturers try to counter waning interest with push notifications, and some of those alerts provide truly useful analysis of the data along with suggestions for energy savings—for example, you might get alerts, based on increased energy usage, indicating that a particular appliance is beginning to fail and will need replacing soon, or that your overall energy usage has suddenly spiked. And every manufacturer we spoke with noted that monitor owners often find creative alternative uses for monitor data. Phillips and McLaughlin both mentioned that they and others have set up notifications from their monitors to track when their garage door opens and closes as a way to oversee family comings and goings. (Grant Clauser, Wirecutter's editor of smart-tech coverage, noted that a smart garage-door controller or even a smart motion sensor can do the same for less money.) Marett told us that many customers watch for an energy spike in the afternoon—indicated by the turning on of lights and video game consoles—to know that their kids have arrived home safe from school.

A range of products are already available that can perform energy monitors’ data-gathering function and add control, coordination, and automation on top of it.

The manufacturers and independent experts we spoke with all mentioned another potential use for monitors: identifying vampire or phantom loads, where devices and appliances are drawing power even when they’re not in active use. But our sources had opposite takes on the practical value of this knowledge. Generac's Keith Marett said, "We see a lot of homes, when it's first installed, their baseline vampire loads are hovering around two kilowatts. That's massive." And it is. But the question is, how many of those vampire loads can realistically be eliminated? Fully shutting off a device means physically unplugging it, shutting off the power strip it's connected to, or installing a smart plug or outlet and using that to shut off the power remotely. The NREL's Bethany Sparn is skeptical that people are likely to do so, and also of the potential for automated, scheduled shutoffs to make much difference: "It's hard to find things that you would really want to turn off on a set schedule that wouldn't impact the use of the device." Sparn also noted that device and appliance manufacturers have made great strides in efficiency in recent years: "The things that used to be a big problem with vampire loads have really improved," she said. "It's a good thing, but it also means there's less opportunity."

Most significantly, another common observation cropped up in our research and interviews: The proliferation of smart technologies and standards like Matter may soon render whole-home energy monitors obsolete or at least peripheral. From the simplest devices (smart outlets or plugs) to smart appliances (refrigerators, washing machines, and the like) to smart electrical panels that can monitor an entire home and let the homeowner control and schedule individual circuits’ usage, a range of products are already available that can perform energy monitors’ data-gathering function and add control, coordination, and automation on top of it.

Ebony Mayhorn, who has been studying energy monitors for well over a decade at the Pacific Northwest National Laboratory, summarized her view on them this way: "I always just saw this as a bridging technology between where we are right now … and what we’re looking toward, where devices and appliances are smarter and they can talk to each other and they can report their own energy consumption. This is kind of a middle technology."

We reached out to seven energy-monitor manufacturers for this guide, and we heard back from and spoke with three of them: Emporia Energy, Generac (whose monitor is based on technology developed by Neurio, which Generac purchased in 2019), and Sense. We didn't hear back from the makers of the Curb, Engage, Eyedro, and Smappee monitors—and there are plenty of other monitors available that we didn't consider in depth. That said, all of these monitors use the same basic technology, and we don't have reason to be especially skeptical of any particular model. But the three we spent the most time with also happen to be some of the most established in the category, with what seemed like the strongest customer support at the time of our research, and they emerged as the energy monitors we would consider first for our own homes or as a recommendation to anyone on the hunt for one.

Sense, one of the earliest monitors available, uses machine learning to identify individual appliances and their electricity usage.

Sense was one of the earliest companies to make a whole-home energy monitor. Its devices use machine learning, taking a million measurements per second of your home's power usage in an effort to identify individual appliances and disaggregate their energy draw—to tell you, in short, that your fridge is using X amount of power, that your dryer is using Y amount, and that some other device is using crazy amounts of electricity and should be tracked down and dealt with. (Always-on swimming-pool and malfunctioning drinking-water and irrigation pumps came up in our research as examples.) The standard Sense Energy Monitor is for use in homes without solar, and is our first suggestion; the Sense Flex lets you monitor your whole-house load as well as two circuits directly via additional sensors, while the Sense Solar can monitor both your utility-supplied mains and your solar panels’ output.

Like all whole-home energy monitors, the Sense units use a pair of current transformers—simple, passive devices that clamp around your home's electrical mains—to accomplish this. And that brings up a general piece of advice: Hire a licensed electrician to install whatever whole-home energy monitor you buy. The mains are always live and carry high-amperage electricity—more than enough to kill. Every manufacturer we spoke with or looked into recommends using an electrician rather than installing the device yourself, and some require that. If you need more convincing, you can find dozens of DIY energy-monitor installations on YouTube—it looks pretty advanced.

Over time, the Sense monitor uses the unique electrical signatures of various appliances, devices, and light bulbs to deliver a granular picture of where you’re using electricity and how much each device is using. Its web, Android, and iOS apps receive data via Wi-Fi (2.4 GHz only) or Bluetooth and give real-time energy monitoring, historical usage, and individual device usage, plus usage in broader categories like "always on" and "other"—the latter meaning devices the machine learning hasn't fully identified. ("Is Sense telling me I have three fridges because I have three fridges, or because it sees three things that have small compressors in them?" is how the NREL's Sparn put it.)

Hire a licensed electrician to install whatever whole-home energy monitor you buy.

That raises the chief complaint we’ve seen from owners about energy monitors that employ machine learning to disaggregate electrical loads: It's a slow and often never-completed process. Sense says its monitor typically identifies a handful of devices in its first month, and 20 to 30 in its first year, but owner experiences vary. Many people report great success; a small but significant percentage (about 15% judging from Amazon reviews) report that even after lengthy use, the monitor has identified few devices, reducing its utility as an energy-saver. EnergySage founder and CEO Vikram Aggarwal installed a monitor that uses machine learning—he did not name the maker, and Sense is not the only one to employ this method—and described his experience thus: "So far it's been a little bit disappointing. The accuracy is not there. It still doesn't tell me, 10 months after installation, where literally 30% to 40% of my electric bill is coming from."

In our interview, Sense CEO Mike Phillips was up front about this concern. "Detecting devices just from their signals is an insanely hard technical problem," he said. "We can't do it perfectly." And though he and many of his customers wish it weren't the case, you can't "train" the monitor yourself: "We have to see all the devices in the home and how they compete with each other in the signature space," Phillips explained. "Just flipping on and off a light five times is not enough."

As of June 2022, the Sense monitor integrates with Philips Hue smart light bulbs and with smart plugs from Wemo and TP-Link—allowing control via the Sense app. It also has some Alexa and Google Assistant abilities and utilizes the IFTTT protocol to add further smart capabilities, including integration with Amazon Alexa, Apple HomeKit, and Google Home.

In addition to the baseline Sense monitor, the company offers the Sense Flex, which adds two individual circuit-level current transformers (letting you directly monitor, for example, your HVAC and washer and dryer usage), and the Sense Solar, which adds two current transformers to monitor your solar production and optimize its usage—sending excess power to the grid or to a storage battery or EV charger, as makes the most sense. Phillips added that Schneider Electric's Wiser Energy monitor "is basically a Schneider-branded version of the same product"—and it typically costs a bit less.

Generac's PWRview W2 monitor, based on the earlier Neurio W1, also uses machine learning to identify devices, and it costs less than the Sense.

*At the time of publishing, the price was $190.

Similar to the Sense monitor, Generac's PWRview W2 uses machine learning to identify individual devices and appliances by their unique electrical signatures. Based on the original Neurio W1 monitor—Neurio, another early entrant into the whole-home energy monitor category, was acquired by Generac in 2019—the PWRview aims to let owners disaggregate their electrical loads granularly and thereby identify ways to save. Like the Sense monitor, it is agnostic—it can work in almost any home, and it uses 2.4 GHz Wi-Fi and/or Bluetooth to connect phones and computers to a native app—but unlike the Sense monitor it is part of a suite of energy devices made by Generac, including solar panels and storage batteries. If you already have Generac systems in your home, this monitor is likely to provide smoother integration and greater functionality. It's also about $100 cheaper than the Sense monitor.

The limited number of PWRview reviews are very positive (it's a relatively new model). Comparing it with the Neurio W1 is not apples-to-apples, but we think it's important to note that the Neurio W1 received a higher rate of complaints than the Sense about both its ability to identify devices and the stability and utility of its apps. On the flip side, Generac's customer service in general receives consistently high marks for its rapid responsiveness and overall helpfulness, while Sense's customer support receives a lot of complaints (the limitation to email communication only and a slow response time predominant among them). That's one reason we’re comfortable recommending the PWRview.

The PWRview monitor employs the IFTTT protocol to provide integration with Amazon Alexa, Apple HomeKit, and Google Home for smart-device control. "Kind of a hacker play is what we really focused in on," said Keith Marett, Generac's president of clean energy services (and former CEO of Neurio). Numerous "recipes" for these integrations are available for free download, and if you’re so inclined, you can also code your own.

As with the Sense monitor, for the PWRview additional current transformers are available to monitor individual circuits and/or a solar array. Notably, Generac bought Ecobee, maker of our runner-up smart thermostat, in 2021. Ecobee has direct Amazon Alexa, Apple HomeKit, and Google Home integration, and Generac is "looking to leverage that," Marett said.

Emporia's Gen 2 Vue monitor doesn't employ machine learning, but you can add extra sensors to directly measure what up to 16 individual circuits are using.

Unlike the Sense and PWRview, Emporia Energy's Gen 2 Vue does not employ machine learning. The basic system is simply a whole-home monitor, measuring your overall energy consumption. Identifying which device is drawing how much power is, by design, up to you, via directly measuring how much electricity a given device consumes by switching it on and off, or through the Gen 2 Vue's numerous integrations with smart devices that can report their own energy use. Such devices include Emporia's smart plugs, smart thermostats from Ecobee, Sensi, and Honeywell, and smart lighting from Hue, Leviton, Lutron, and Kara. Further integrations with smart appliances are planned. "People are looking for that phantom load, or wondering how much a specific appliance uses, and they can turn on, say, the microwave and see instantly how much energy it's consuming," said Emporia founder and CEO Shawn McLaughlin. In contrast to the machine-learning approach, "we just felt like hardware was the better way to solve disaggregation," he added, not least because leaving the work of identifying loads to the owner cuts the cost of an energy monitor significantly. The basic Gen 2 Vue costs less than half of what the basic PWRview does, and less than a third of the basic Sense monitor.

You can also buy versions of the Gen 2 Vue that come with eight or 16 circuit-level current transformers, which let you monitor the usage of individual circuits, such as those that power your HVAC, boiler, and laundry room. Or you can add those current transformers later. Consisting of little more than electrical wire, they don't add a ton of cost: Even the 16-transformer bundle costs less than the basic Generac PWRview up front. And installing the individual circuit transformers doesn't involve the mains, so you can just shut off the breaker box and clip them onto circuits, free of electrocution fears. (But again: Hire a licensed electrician to install the mains system, since the mains are always live.) If you’re ready to spend some time flipping appliances, devices, and switches on and off to identify what role they play in your energy usage (and to identify unknown phantom loads by elimination), the Gen 2 Vue is an economical option. Like our other recommendations, it has Android and iOS apps plus a web app, and it needs a 2.4 GHz Wi-Fi network to connect; it lacks Bluetooth support, however.

We asked all the energy-monitor manufacturers about how they handle customer data and device-usage information, and though their approaches vary, we’re satisfied that they take the responsibility seriously. The data that seems to raise the most potential red flags among customers is location data, but the manufacturers are not interested in where you live, per se; instead, knowing your general location allows them to do things like figure out your electricity supplier (via the National Renewable Energy Laboratory's database) and thus identify your local time-of-use rates (for maximizing efficiency via smart devices that can work or charge during off-peak hours). And when solar systems are integrated, knowing your general location helps them predict future solar production via local weather forecasts.

Emporia's Shawn McLaughlin said that all sensor data transmits as encrypted binary code, "literally a bunch of ones and zeroes," under MQTT protocols and within the Cognito security system from Amazon Web Services. "There's no customer information, there's no personal information—all it is is usage data in an encrypted binary package." Emporia's devices all receive a unique token identifier, he added, "so if someone were to hack into one piece of hardware and somehow figure out what that token is and try to use that to access data in the cloud, they’d only be able to get it for that one device."

Generac's Keith Marett said, "We take cybersecurity incredibly seriously," adding that Generac has an entire cybersecurity department. The company does not require your home address when you register your monitor ("We don't need it") but instead uses your zip code and utility to find local time-of-use or flat rates. If you don't want to provide even that much information, you can manually load your own rates, and Marett said that monitor data and account info are kept in totally separate encrypted databases.

Sense CEO Mike Phillips said, "We made a decision as a company from the early days that we are staying on the consumer side of this. We’re not taking people's data and selling it to the highest bidder or anything like that. In fact, our terms of service are that you as a consumer own the data. We get rights to certain things, but we don't have the right to sell it in any personally identifiable way."

We reached out repeatedly to four other energy-monitor manufacturers but never heard back. Any of the following energy monitors could be perfectly good devices, but without the ability to hear about how they work and perform, we couldn't get as far in answering questions as to whether we would recommend them. We remain open to discussing these models, and we hope to have an opportunity to update this guide with input from the makers of these monitors.

The Curb Energy Monitoring devices from Elevation are circuit-level monitors, with the basic model featuring two circuit transformers for the mains and two for hooking to individual circuits of your choosing; the upgrade options feature eight or 16. You can't buy and install a Curb monitor yourself—instead, your purchase includes professional installation. We think that's a smart thing, safety-wise.

Like the Sense and Generac monitors, Smappee's Infinity SMP Series monitors use machine learning to identify major appliances, and you can add circuit-level current transformers for direct measurement of circuits you want to have direct data from, such as those that run your HVAC or EV charger—major users of electricity.

Efergy's Engage monitor is a simple device that, like the Emporia Gen 2 Vue, comes with two mains current transformers. You can add up to five circuit-level transformers for direct measurements of those circuits’ energy draw.

Eyedro's home electricity monitors feature two or four current transformers for the mains or individual circuits, again similar to the Gen 2 Vue.

This article was edited by Harry Sawyers.

Vikram Aggarwal, founder and CEO, Emily Walker, content marketer, and Nick Liberati, communication manager, EnergySage, video interview, May 9, 2022

Bethany Sparn, senior researcher, National Renewable Energy Laboratory, video interview, May 18, 2022

Ebony Mayhorn and Josh Butzbaugh, senior researchers, Pacific Northwest National Laboratory, video interview, May 25, 2022

Keith Marett, president of clean energy services, Generac, video interview, May 13, 2022

Mike Phillips, co-founder and CEO, and Emory Griffith, product manager, Sense, video interview, May 12, 2022

Shawn McLaughlin, founder and CEO, Emporia Energy, video interview, May 17, 2022

Tim Heffernan

Tim Heffernan is a senior staff writer at Wirecutter and a former writer-editor for The Atlantic, Esquire, and others. He has anchored our unequaled coverage of air purifiers and water filters since 2015. In 2018, he established Wirecutter's ongoing collaboration with The New York Times's Smarter Living. When he's not here, he's on his bike.

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