Knowledge is power: energy monitoring guide
Need help getting the upper hand on your electricity bills or checking that your solar system is working? You should consider an energy monitoring system, says James Martin from Solar Choice.
This article was first published in Issue 141 (Oct-Dec 2017) of Renew magazine.
Do you have a clear picture of what’s drawing electricity in your home right now? If you’re like most Australians, you probably don’t.
Historically, this hasn’t been an issue because electricity bills weren’t a major concern for most households and, in any case, the number of devices was probably small. But these days electricity prices are high and there are likely to be more electricity-consuming devices plugged into the walls of any given home than the occupants can think of off the top of their heads.
Many Australians have turned to solar panels to help them fight rising prices. Rooftop solar is now affordable and commonplace—the Hills Hoist of the 21st century. However, comparatively low solar feed-in tariffs in most places mean that solar homes have less incentive to send solar electricity into the grid and more incentive to use it directly. Despite this fact, many (if not most) solar system owners would be at a loss if you asked them how much energy their system produced yesterday, never mind the proportion that they managed to self-consume. Solar systems have even failed without the homeowner realising until they received their next bill. So monitoring is important!
Types of energy monitoring and management systems
Thankfully, there’s a growing number of products on the market that shed light on household energy consumption and solar generation. These devices take a range of approaches and offer a range of functions, but can generally be classed as either monitoring systems or management systems.
As the name implies, a monitoring system enables the user to ‘see’ what’s happening with their electricity, usually via an app or web-based portal, whereas a management system lets them not only observe but also ‘reach in’ and control which devices switch on at what times. In reality, the line between the two is becoming increasingly blurred as platforms that once offered only monitoring get upgraded to let them do more.
Monitoring and management systems can be lumped into roughly five categories based on how they are physically installed in the home.
Monitoring: what and what level of detail?
When it comes to knowing what’s happening inside your home energy system, different platforms have different capabilities. Below is a breakdown of parameters that a system may be able to monitor, useful to keep in mind for asking questions as you shop around and compare monitoring products.
Note that the time increments for monitoring will vary by the system installed. Some will show data flows in real-time or near real-time, while others may show it in 15-minute or half-hourly chunks. Most systems will show some kind of historic analysis as well, so that you can compare recent data to past data to gain insights and improve your home’s energy effectiveness.
Control: what and how?
The next thing to consider is the system’s control capability: what appliances and devices can be monitored in the home, and how does it manage them? Below are some questions that are useful to ask when trying to decide between products.
- On/off control. Can the system be used to switch things on and off, either at the device or circuit level?
- Remote control options. What are the options for remote control, e.g. on/off switch, timer schedule, algorithm/rule-based?
- Remote adjustments (beyond on/off). If control happens at the device level, are more subtle adjustments to device operation possible, e.g. adjusting the thermostat on an air conditioner?
- Third party control. For a system that has a central hub, will it communicate with third party devices such as smart plugs or other ‘internet of things’ (IoT) appliances?
- Communications protocols. What wireless mediums can be used for control, e.g. Z-Wave, wi-fi?
- Solar diversion. For systems with solar, can certain devices be automatically switched on when excess solar energy is available, e.g. water tank element?
- Charging control. For systems with batteries, can batteries automatically be pre-charged with cheap off-peak grid electricity to meet demand on days when low sunlight levels and high energy usage are anticipated?
Depending on the product, there are a number of other bells and whistles that may come with the system. Some of the potential extras include:
- Notifications and warnings about the home energy system, e.g. if you’re using significantly more energy than usual or if there is a dangerous ground fault in a solar PV system
- Integration with home security systems, electric vehicle charging systems, etc
- Solar or battery sizing recommendations, for homes that don’t already have them.
How does it connect?
One other thing to keep in mind when choosing a monitoring or management system is how it connects to the internet to enable it to log data and be controlled remotely. The two most common ways are standard wi-fi and GSM/mobile phone.
Wi-fi is a popular option because it is ubiquitous in modern homes so likely comes at no additional cost. However, wi-fi connections can be unreliable and troublesome to reestablish in the event of an outage. Wi-fi connections are also less secure than GSM connections, which may raise privacy and safety concerns.
Monitoring/management systems that use GSM connections are generally more reliable and more secure than wi-fi. However, they may come at an additional monthly cost. Be sure to check the specifications of the units you’re considering as well as the terms of sale to know what you’ll be committed to before you make your decision.