Monitor your home energy use
HAVING A SMARTHOME IS NOT JUST ABOUT COOL TECH, IT’S ALSO ABOUT THE WAYS IN WHICH WE CAN MAKE TECH MORE ENERGY EFFICIENT.
A BIG FOCUS in smarthome technology is smarter, more e cient use of electricity, to reduce power bills, as well as environmental impact. Energy monitoring systems can help identify appliances and usage trends that consume a lot of power, and provide the data needed to make e ective changes.
ENERGY MONITORING BENEFITS
While solar and battery storage systems such as the Tesla Powerwall are o en touted as methods to reduce electricity costs, simple reducing consumption can be just as e ective. Of course, knowing how much you actually use day to day, and even minute to minute, is key. To make it easier, there is a range of products available that can track energy usage and bring the information together in an easy-to-understand dashboard. Going a step further, it’s possible to remotely shut down energy-hogging devices, and set goals and alarms for consumption.
While many users have at rate energy prices, time of use metering is becoming more popular. By tracking when and what is using the most power in peak times, usage times can be changed to save money without even needing to reduce overall consumption.
Another large consumer of power is idle load from electronic devices. While more modern appliances generally drop idle power to very low levels, some older equipment draws a surprisingly large amount of electricity even when o . is adds up over time, and identifying and reducing idle draw is a great way to save money. Energy monitoring is also a great way to better understand where power is owing in a solar or battery storage setup.
EFERGY
www.efergy.com Featuring a large range of products designed to track and display energy usage, Efergy is a great starting point for smarthome power monitoring. Getting hands on, we installed and tested some of the most popular devices as part of our guide to smarter home energy monitoring. Using the Efergy platform, everything from whole home power to individual appliances can be tracked. Also included is a free online platform, which provides a simple graphical dashboard, that gives an instant view of power use, as well as enabling detailed consideration of trends over time. It’s even possible to remotely control individual appliances with Wi-Fi-connected power tracking switches.
OTHER OPTIONS
While one of the best, Efergy is not the only monitoring system available. e popular Belkin WeMo range ( includes a power monitoring and remote control wall switch called Insight, which can log consumption from a particular socket. It doesn’t have the main feed line electricity meter level of data logging, though, but can be easier to tie in with other smarthome functionality. Power Tracker ( www.powertracker.com.au) and SMA ( www.sma-australia.com.au) are two more companies that both o er a range of networked and internet-connected power tracking products. Another basic option for those getting started are power meters such as the MS6116 from jaycar.com.au, which cost under $25 and track usage on a single power point, with no online connectivity.
PRODUCTS
Efergy has a huge range of products designed to monitor power use in di erent scenarios. ese are available in a range of ready-to-go kits, as well as being sold individually. While some use an internet-connected hub as a central connection point, others work directly with a monitoring display or smartphone.
SENSORS
e Efergy system uses non-contact CT sensors to monitor how much power is owing through a live cable. ese work as a transformer, where AC current in the wire induces a current in the sensor, which is then measured, and transmitted wirelessly back to a hub. e basic kit of a sensor, transmitter and hub costs $149.95, and adding extra sensors cost $69 each. Just the hub costs $79.95. Starter kits for solar system monitoring ($229.95) and three phase ($169.95) are also available. A power monitoring Engage Socket product is coming soon to allow data collection from individual appliances.
DISPLAYS
While all the data can be viewed online or via smartphone app, Efergy also has two portable wireless displays. ese can receive and display the power use directly in real time, to make monitoring super quick, without the need for internet access. e displays are available separately, or as part of di erent starter kits.
e Elite Classic costs $99.95 (and comes with a CT sensor and transmitter) and displays real-time data on a large screen, with activatable backlight. It’s mains or battery powered (12-month life), and can record and display 12 months of historical kWh usage data. e display can also be set up to calculate and show the power cost, based on your rates, as well as show CO2 produced. It can be set to sound an alarm if a pre-set consumption target is exceeded. e Elite Classic doesn’t need a hub or internet connection to operate either, but its data can’t be automatically logged elsewhere. is is a great option for those who want a simple readout and basic historical power use data (such as solar monitoring), without any extra complexities.
e e2 Classic ($129.95) o ers the same functionality, with a few extra features. For a start, it can monitor and store up to 24 months of data. Using Efergy’s elink 2.3 so ware, the recorded information can be downloaded to a computer and viewed as graphs, or outputted as a spreadsheet for further analysis.
EFERGY EGO
e Engage systems are great for whole-house or circuit monitoring, but not to see how much your home theatre gear is using when turned o . e Efergy Ego is Wi-Fi-enabled device that plugs between your appliance and the wall socket, and records the power usage. Even more importantly, it can be remotely turned on and o to cut any parasitic idle electricity use. e switch also has smarthome uses, such as remotely turning on an appliance. We tested it by tracking the power used by a fridge, AV equipment, and activated an electric kettle each morning so it was boiled and ready for a morning co ee. e Ego is controlled and monitored via a free Android or iOS smartphone app.
INSTALLATION
While units such as the Ego can be simply plugged in, the CT sensors have to be clipped over wires. As a non-contact technology, these can be installed without an electrician, but it’s highly recommended to use a professional. In our case, we got help from a relative with an electrician’s licence. For those living in strata titled units or townhouses, special permission may be needed, and the distance from transmitter to receiver hub may be too far for reliable transmission.
CT SENSORS
Installation procedure will vary a lot depending on the type of electrical meter and panel. Our system is particularly ancient, but that did allow for easy access to the underlying rat’s nest of wiring. e sensors come with installation instructions, but they don’t match all power meter types. If in doubt, Efergy themselves can help identify the correct wire. For extra monitoring, we clipped CT sensors onto our main feed line, o peak line, and the one lighting circuit. From there, the separate wall socket consumption can be calculated.
e actual installation is as simple as clipping the CT sensor onto the live feed wire, running the cable clear and plugging it into the transmitter. Our hub was on the opposite side of the house to the meter, so we found that leaving the transmitter in the electrical box itself shielded the wireless signal and caused an unreliable connection. Since the units are waterproof, we mounted them under the electrical box with double-sided tape. A drilled hole allows the wires to exit the meter without blocking the electrical panel door.
Another more complex option (speak to an electrician) is to mount the CT sensor on a wire behind a single power outlet. is then allows tracking of the usage from one particular device, such as a fridge.
ENGAGE HUB
is little unit plugs into your router and receives the signals from the CT sensor transmitters, and logs them. It needs mains wall power, as well as a single Ethernet connection and internet access. A er creating an account, the monitoring system walks you through connecting the transmitters. In our case, the auto-search picked them up and started logging data right away. To make sure the data was accurate, we red up a high draw load (an electric kettle) and watched the power draw spike immediately.
ELITE CLASSIC DISPLAY
We set up and tested the LCD as if it was installed independently to the monitoring system. is mimics use by a household that just wants an easy-to-read power meter, with some data tracking, not an internet-connected system. e transmitter and CT sensor included with the Elite Classic is the same as the others used in the Engage system, so installation was as simple as clipping it onto the main feed wire. Getting the two connected just involves pressing the link button on the display, and turning on the transmitter. e screen is rated for a 70m range, but we mounted the transmitter outside of the power meter.
AS A NON-CONTACT TECHNOLOGY, THESE CAN BE INSTALLED WITHOUT AN ELECTRICIAN, BUT IT’S HIGHLY RECOMMENDED TO USE A PROFESSIONAL.
MONITORING AND RESULTS
To get a better idea of individual device power usage, extra CT sensors can be installed on di erent circuits, or the one sensor can be moved around. For example, sensors could be used to monitor the lighting circuit, hot water system, kitchen appliance circuit, air conditioner circuit and more.
COST AND CO TRACKING
e Efergy online dashboard allows you to enter an electricity price in cents per kWh. From there, it can calculate how much your energy use has cost each day, month or from a specific date. You can nd the per kWh price on your bill, though some have multiple tari levels depending on overall use. In such a case, dividing your total power use in kWh by the usage charges will give the average kWh price. Be aware that the supply charge is a separate value to usage.
e Efergy system can also calculate CO2 emitted, and uses a default value of 0.5kg per kWh. While this is a decent starting point, for a more accurate number, try contacting your energy supplier.
ANALYSING THE DATA
e Efergy dashboard includes a simple graph with selectable options that makes it easy to compare power cost, kWh usage and CO2 emissions, over a period of a day, a week and a year. For those who like to play with the numbers in more detail, the system can also generate a report in CSV format. is can be set to a data resolution of as little as every minute, and cover a selected month. It also includes the raw data from all sensors tied into your account. A good starting point (a er recording some baseline data) is to try turning o power points for TVs and other devices when not in use, and compare overall power use information.
EFERGY EGO
Unfortunately, the Ego system does not mesh into the Engage power monitoring, and instead uses its own app. Setup involves plugging in the Ego unit, and connecting to it via the app. is turned out to be a complex process, as the automatic connection did not work. Instead, it was necessary to manually add the Ego switch. Afterwards, it was necessary to reset the phone before it would run stably.
e Ego app allows data collection and realtime viewing in a similar fashion to the Engage dashboard. You can input your electricity price per kWh, and calculate costs and CO2 emissions. Historical data can be viewed on a daily, weekly or monthly time scale. You can also compare di erent switches, set up on/o timers, and have the Ego learn to disable idle power draw.
Using Ego, we tracked a whole range of di erent appliances to get a better idea of their power use. A notable discovery was that the washing machine draws ~30w when not in use, which adds up to a very signi cant $60 a year added to the power bill. One large overall consumer of electricity was the fridge, which chewed through 518kWh a year. Interestingly, sliding it out about 5cm and removing items on top that impeded cooling airflow dropped the usage by 14.3%, saving 74 kWh, or $17 a year. Every little bit counts!
A GOOD STARTING POINT (AFTER RECORDING SOME BASELINE DATA) IS TO TRY TURNING OFF POWER POINTS FOR TVS AND OTHER DEBICES WHEN NOT IN USE, AND COMPARE POWER USE.