Part 2 in our series on managing and monitoring energy production and consumption in your home, apartment, or flat.
David Allen, the noted author and personal productivity guru, once wrote: “Your ability to generate power is directly proportional to your ability to relax.” Now, I am an Allen fan and enjoyed reading his 2001 book, Getting Things Done: The Art of Stress-Free Productivity, but was he foretelling a kicked-back lifestyle for today’s zero net energy homeowners, their rooftops resplendent in rows of azure-hued solar panels?
Probably not, given the singular focus of Allen’s lifehacker book on reorganizing the myriad tasks in our personal and professional lives into manageable, stress-free workflows. What is decidedly true, however, is that a rooftop solar panel installation is probably one of the lowest-maintenance components of today’s high-performance homes. That is not to say you should install them and forget them, however. They should be appropriately managed and monitored to ensure they continue performing the power-production jobs you hired them for.
Largely attributable to sophisticated software embedded in many solar installations and anytime access through mobile apps, you may never need to ascend a ladder to monitor the health of your photovoltaic panels. That is certainly the case in our lab home, where we deployed a grid-tied, 7.75 kW system that was fully enabled for remote management and monitoring. The rooftop installation consisted of 33 Trina Solar photovoltaic panels—secured to our standing-seam Galvalume metal roof via an aluminum racking system—and connected with microinverters from Enphase Energy. To enable remote management and monitoring of the system, we installed the Enphase Envoy, a networked gateway that enables real-time communication with the Enphase Enlighten suite of software and apps.
In such a microinverter-based system, each solar panel is paired with a dedicated microinverter box that is typically installed directly beneath the panel. The microinverter’s primary job is local conversion of the direct current (DC) produced by the panel to home-compatible alternating current (AC). In our case, we used the Enphase M215 microinverters, devices ready to communicate with the Enphase Envoy gateway straight out of their boxes.
As Enphase has evolved their solar system installer-oriented Enlighten Manager and the more homeowner-centric MyEnlighten monitoring software over time, it has become increasingly powerful and sophisticated. While we have not had an opportunity to test-drive similar software from other manufacturers, we can testify that the Enphase mobile apps for iOS and Android are exceedingly user-friendly and designed from the ground up for mobile, touch-screen usage, but they can work equally well in a traditional browser.
To tap into the most comprehensive set of data around your arrays, the Enlighten Manger would be the tool of choice. In fact, in all likelihood, your Enphase system installer used a more advanced version of this tool during the installation and configuration of your arrays, and installers can also use the same software to remotely troubleshoot issues that may arise at your site.
While the software can provide real-time snapshots on the performance of the entire system, the capability to drill down into the individual microinverters—and by association the current and historical data originating from its paired solar panel—can be quite valuable. Need to understand how a single solar panel performed for a specific date or date range since it was installed? Enlighten Manager can replay the power production metric (in watts) through a minute-by-minute animation, or read out total energy production (in kilowatt hours).
Another aspect of Enlighten Manager we appreciated is the ability to graphically depict power or energy production for a given date range, either across the entire system or for a given solar panel. Clicking on any area in the chart reveals a pop-up with the metric for that point in time.
By contrast, the MyEnlighten app is designed to provide energy production information on the system as a whole, and most homeowners may find this is the only app they need in order to keep tabs on the health of their installation. The Overview tab can display production metrics for any given day since the system was installed, and includes a numerical view of the day’s production, a graphical representation of the arrays, and a bar chart with energy production depicted in 15-minute increments throughout the day.
Through the Production tab, the particularly-powerful matrix view can be accessed by selecting among the Months, Days, or Hours sub-tabs. Each cell in the matrix is shaded in gradations of blue, ranging from dark blue (for the lowest energy production levels) to light blue (for the highest energy production levels). Touching or clicking any cell reveals the total production in kilowatt hours for that time period, plus a corresponding bar chart at the bottom. For example, using the Days tab in the iOS app on an iPad, it is possible to display energy production for 11 months, with each cell in the matrix representing a single day. And on the smartphone version, we were able to display 24 months of daily data, again with each day’s cell clickable to glean energy production data.
Alternatively, you can use the graph view in MyEnlighten to instead display a bar graph, again by selecting among the Months, Days, or Hours sub-tabs. As you would expect, this generates a primary bar chart, and a secondary matrix view appears at the bottom for easily navigating between the respective months, days, or hours.
MyEnlighten can also be configured to associate your solar installation with a specific weather station from the extensive Weather Underground network, and then that weather station’s temperature readings and weather conditions are integrated into the MyEnlighten interface. Once that association is made, it is possible to view real-time weather conditions on the Overview tab as well as the historical high and low temperatures from any date or time selected in MyEnlighten. Hyperlinks enable clicking straight into the respective weather station’s dedicated page on the Weather Underground Web site.
Tools such as Enlighten Manager and MyEnlighten are excellent additions to your home-front management tool kit and quite highly evolved, enabling at-a-glance system health, access to drill-down performance data, and much more. One downside, however, is that this class of tools can only provide insights on your rooftop energy production—they have no visibility into your home’s energy consumption metrics. In a later installment of this ongoing series, we will delve into whole-house energy monitors, hard-wired tools that can measure and track both local energy production and consumption.