Going Solar - Enphase Envoy

Part V - Enphase Envoy - the brains of the outfit

The Enphase Envoy, in my case, the Envoy-S Metered, keeps an eye on the IQ7+ micro-inverters. It also communicates back to base somewhere on the cloud. In addition, it can also measure the amount of power your solar array produces and the amount of power you consume. All in all, this is a piece of equipment that deserves its own blog post.

With all the analysis that went into the solar array, it is obvious that I would want to keep a close eye on it once it is in operation. And nothing helps me do that more than the Enphase Envoy-S Metered. I was offered and took an option that usually costs an extra $300 but it was offered at no extra charge. I am not quite sure what this included but may have something to do with panel level monitoring.

The Envoy comes with current transformers that can monitor both the production and consumption. The difference between the two values gives you the net power you get or feed back into the grid. The Envoy comes with 2 current transformers but can take up to 6. With a 3 phase supply I needed all of them.

The bottom edge of the Envoy shows a series of terminals for the the connections. On the left is the power supply connection – 3 phases and neutral. This may also let the micro-inverters on all three phases to communicate with the Envoy without needing a coupler. Then come the 3 production and the 3 consumption current transformer connections. The last set of connections is for DRM/DRED. The wiring diagram for the Envoy is straight out of the instruction manual.

The photo above shows one of the six current transformers. There is wide range of current transformers available from Enphase. This one is rated at 100A.

The current transformers come with a long blue/white twisted pair wire to connect to the production/consumption connections on the Envoy. The other 'end' is clipped around the right wires on the main electrical board. On the left, the current transformers have been wired into the Envoy and are dangling down. On the right, the current transformers have been clipped on to the right wires.

Once installed, the installer uses an app to setup it up so that the Envoy can connect to your home WiFi. The consumption meters can be installed to monitor the load after the input from the solar array or monitor the load including the output of the solar array. The second is the more common option and this is configured into the web application by the installer. Once the WiFi is configured, the Envoy starts sending detailed information back to Enphase on the cloud. It can also be used by Enphase to upgrade the software. You can monitor how your array is doing by logging on to the the MyEnlighten web pages. Your installer will set up your user id and password. Optionally, instead of WiFi, the Envoy can use a LAN connection or a GSM modem to connect to the cloud.

The main page shows the amount of power generated by the solar array and consumed by the whole house for the day. You also get a detailed graph for the day showing the production and consumption in 15 minute intervals. Kudos to Enphase for that graph that encompasses all that information. The dark blue bar shows the excess power you are generating being fed back to the grid, the light blue the power generated that you are consuming locally, the dark orange for the consumption when you draw power from the grid and light orange for the consumption that was generated by your solar array - all that information clearly shown in a single detailed graph.

There is a more detailed panel level monitoring available. Even though I have specifically asked for it during the quote, I have not yet received it. It lists all the equipment monitored by the Envoy. Besides the inverter, it also lists the production and consumption 'meters' (these are not real pieces of equipment, just modules inside the Envoy) and the Q relay isolating the solar array from the mains. Each micro-inverter is listed along with its serial number, the wattage at that instant and the power generated over a day. This allows you to monitor the performance down to the panel level. As usual, your installer will put a schematic diagram of your panel layout. Clicking on the micro-inverter in the list takes your to the panel schematic and zooms in to the exact panel. This should provide you with the last bit of information - which micro-inverter+solar-panel is where on your roof.

As mentioned before, the connectors to the right are the DRM/DRED ports. This is expected to be used in future. DRM stands for Demand Response Management and DRED stands for Demand Response Enabling Device. When installed and configured, it will allow your power company to selectively shutdown your production or consumption (with your permission, of course!). This means they can slow down or shut your Aircon for instance to help them handle any system-wide load. They can also slow down or shut down the amount of power you are pushing back into the grid.

The Envoy also has a local web server. The IP address could be deduced from your router. There is an endless amount information that can be gleaned down to panel level performance. As a starting point check out this web page to get started. Do read the comments below the blog post - they have a lot more additional info. I am already working on a program that shows the performance of my solar array for a day, down to the panel level.

The Envoy can be queried to get the current status and some cumulative statistics. If you are after historical data, you can use the Enphase API. This is free for low volumes.