in Greener Homes on 17 June 2012
Put your energy into measuring electricity consumption
EVERY time you press down on your toaster, it costs you money. But how much? And how does that compare to your second fridge? Or the air conditioner?
Something’s been missing in between our power points and our utility bills. Most of us don’t know how much electricity we’re consuming, let alone which of our gadgets take most of the load.
Five years ago, Sam Sabey started tinkering with a way to show electricity consumption in real time, working on the principle that we can’t change what we don’t measure. The project began at the Melbourne HackerSpace, a weekly gathering for tech hardware enthusiasts.
Mr Sabey’s hobby has now become a business, called Smart Energy Groups. His product – the SEGmeter – is a set of current sensors that detect the electricity flowing through the different circuits in your home. It sends the information to a web platform, which displays it in all manner of graphs and charts.
“It’s the ultimate energy saving gadget,” he says. “The data tells a story – it’s a wonderful tool to help make the invisible visible.”
Earlier this year, Mr Sabey and his family moved house. With the SEGmeter, he discovered that their new home was consuming 400 watts in the middle of the night. One of the main culprits was the air conditioner, which drew 60 watts, even when it was switched off.
“It’s about understanding when and where we’re using electricity,” he says. “Every house is different and they don’t come with an energy efficiency manual.”
A SEGmeter for householders with 6 different channels, costs about $1000, including installation. Mr Sabey says it’s best suited for big electricity users who want to reduce their bills, and also for houses with solar panels, because it reveals the split between production and consumption.
Some of his findings are quirky: “I now know that when my wife cooks herself bacon and eggs for breakfast on our induction stovetop it costs 6 cents,” he says.
Others are more significant: his solar hot water booster was running too long during the night, because the temperature setting was unnecessarily high.
“It’s a really good way to show you where your energy blackspots are – things such as my hot water unit. Some of them will be really low-hanging fruit, but they can be difficult to find without ongoing monitoring,” he says. “It’s also a gentle reminder to check how you’re going, because behaviours can improve and they can also slip back.”
Mr Reefman says that while the expensive meters will help households save money in the long run, there are cheaper alternatives. Simple in-home displays are available from electronics stores and eco-retailers for around $100.
Until now, smart meters haven’t delivered useful information to householders, but that seems set to change. Electricity distributor Jemena is trialling a web portal that will display its customers’ electricity data online. But, like the simple in-home displays, it will show total consumption, not a breakdown of what uses what.
If you want to measure individual appliances, you can try a Power-Mate, an Australian-made gizmo that plugs in between the socket and an appliance and tells you exactly how much juice it’s guzzling.
Illustration by Robin Cowcher