We all know the story, you need to be able to measure something before you can set about implementing changes. It’s no different for your home’s power consumption, so lets get measuring and saving.
Gladly we can point out right from the start that there is no subscription here as efergy commit to making this a free service for life. You can also get your data out too, but more on that later.
Installation & Setup
The box includes a CT Clamp, Transmitter, Receiver, Mains adaptor and Ethernet cable. Installing the kit is a 20 minute job. The Current Transformer clamp goes in your meter box and plugs into its battery powered transmitter.
You’ll need to hunt for 3 x AA batteries for the clamp transmitter as these aren’t included. Luckily we had some spare rechargeable cells. Efergy quote a battery life of between 18 and 26 months for the clamp transmitter.
The clamp uses 433MHz to communicate with the receiver and efergy say they are moving to the OpenThings open protocol for these comms in future.
The mains powered receiver needs to be plugged into an Ethernet port somewhere on your wired home network. Most people would prefer WiFi these days though and if you don’t have a wired LAN then you’ll need to site it next to your router which may not be the most convenient location to receive the signal from the clamp. For us though our Node Zero lies right behind the meter box so is ideal for reception and plugs straight into our network switch.
Once everything is connected and you have 3 green lights it’s off to your browser to follow the setup instructions on screen. The hardware is auto-discovered and updated to the latest firmware. A few clicks and you are done.
Using the System
As well as your real-time current usage there are daily, weekly, monthly and average costs graphs available. You can input your unit price for the best approximation of the cost of your power consumption and also set a monthly budget amount too. The data can be viewed in £’s, kWh or CO2.
If your Internet goes down the hub will retain approximately 30 days worth of your data (in one minute intervals) to sync up when the connection is restored. Data storage on the Cloud is quoted as ‘unlimited’.
The clamps range is 50mA to 200A (90-600V) and we asked efergy how accurate its measurements are and they told us…
The clamp is 95-99% accurate. With higher power levels the accuracy is higher. We have made third party tests that shows this accuracy levels. We also have an optical sensor that measures the optical pulses from the meters, showing an accuracy of 98-99%.
Even if this method of measurement isn’t great at measuring smaller loads, this is mainly about spotting relative trends and making changes like spotting you need an immersion heater timer.
Solar PV Monitoring
Efergy say the engage hub is also ideal if you have a PV Solar installation. A separate clamp can be ordered and placed on the cable coming from the solar inverter. This then measures the output from your system and shows it on the graph too helping you see if you are using the power your PV system is generating most efficiently.
Efery have a couple of useful ways of using your data. Firstly you can export a csv file of values to download to your PC or Mac.
Alternatively if you like to get your hands dirty with a bit of coding you can use this open API that employs a (revokeable) token to query the Cloud for your measurements.
Efergy tell us there is currently a “mayor mobile company” in the UK that is carrying out trials with this system and it’s being installed by utility companies for smart meters too.
All About the Bass(line)
Currently the lowest our house goes (when all is quiet over-night) is around 650 watts. That’s the constant baseline consumption from things like the fridge, freezer and other devices plugged in and running or on standby.
To find the worst culprits here you can use something like this to measure the consumption of individual appliances.
There’s a new engage socket (pictured right) thats coming in Q3 2016 that will monitor individual appliances (up to 5 sockets on one hub) that should be priced around £15.
It has also given us the impetus to go and buy more of these great LED Bulbs to swap over more of the most used rooms in the house. We still have around 50 of those evil 50w incandescent GU10’s halogens to replace though and even with the recent price drop that’s still over £400 worth of bulbs required.
Seeing is Believing
All this stuff helps concentrate the mind. The day after I installed the system I was looking into my tariff on my electricity suppliers website and realised I could do a lot better. A quick call and I had saved over £200 for the year…
Electricity price dropped 12.3% + £30 credit to my account just by calling existing supplier. Over £200 saved annually. #GetPhoningPeople
— Automated Home (@ottomate) May 4, 2016
Efergy make several other energy monitors, here’s a good comparison chart of the features. They tell us they are committed to developing the engage hub with an upgraded Cloud service due in Q3 this year which will add the ability to use multiple tariffs and will lead to new versions of the mobile apps too.
Even without these promised enhancements we can heartily recommend the efergy engage hub as a convenient way to measure (and hence improve) your home’s energy consumption.
Available now for around £40