Is there any way to get the Power Meter on the Sense app and/or Webapp to plot negative values that arise due to PV flow into the grid?
I have a need to use the “Solar” meter plug for tracking of specific device power use, so I can’t add a Solar input meter. It would be nice if the Power Meter displayed both positive and negative power flow.
I am new to this forum. I searched for something related to this, but did not find anything that gave me an idea of how I might accomplish this.
Help me understand the use case. So you want to use a Sense attached to your house mains when you have solar, while using your auxiliary CTs (Flex Sensors) for direct circuit monitoring (DCM), not on your solar feedin ? That would mean that Sense would be showing Net Usage that would go negative, without the ability to show Total Usage, and of course, screw with all the solar and total usage energy usage in the Trends.
FYI - I have a second Sense set up like you are contemplating, but only use it for two 240V DCM readings, one for one of my EVs and one for my entire floor heating circuit with 4 different loops. Wondering what you would hope to achieve with seeing the full axis on the Power Meter. Even with that, all the other Trend energy data would be screwed up because it’s all based on non-negative Total Usage, so daily, monthly and yearly usage would only reflect the hours with net positive usage (negative hours are zeroed out). Here’s an interesting example from my second DCM Sense:
My current Sense setup:
Sense Flex, four CTs.
Two CTs on Mains.
One CT on a 120v hot tub.
One CT on one leg of a 240V EV Charger.
I want to have a DCM on those two devices (hot tub and EV Charger).
PV+battery backup feeding a charge controller and an inverter. This has all the requisite rapid disconnect, critical loads panel, etc. All the trappings.
The Solar system watches everything going into and out of the solar, and watches the grid recharge the battery in the winter if we don’t produce enough solar to fully recharge the battery. What it can’t see is anything not on the critical loads panel.
There are several circuits not on the critical loads panel. In particular the hot tub and the EV charger (there are a few others as well, but they’re not as important), so I don’t have any insight into what they’re doing except through the utility’s flakey reporting or through something like the Sense DCM. The PV system’s tracking doesn’t see anything not on the critical loads and the Sense mostly doesn’t see anything on the critical loads.
Sense can read the circuits on the critical loads IF there’s a draw from the grid (at night after the battery reaches its minimum SOC, for example), but I suspect it cannot see anything during the day when power feeds from PV to the critical loads.
With your response, I’m wondering if Sense is the wrong solution and if I should look for a system with more CTs so I can clip a few around the critical loads as well as the main panel. I was just hoping to also get the machine learning ability that Sense seems to be developing.
My 2c - There are a number of other systems with CTs for many circuits - WelServer, Emporia Energy, plus many smart panels from players like Square D, Leviton and Span. None of those were good options for me because I have about 100 circuits spread across 3 panels. I’m guessing none of those are good options for you either because you likely require customized interpretation of the measurements, not just tons of measurements. I’m guessing that you would be better served by Home Assistant for more customized data integration and visualization. With Home Assistant, you can collect energy data from multiple sources, process it and turn it into the graphs you want, rather than relying on each measurement platforms’ canned set of calculations and graphs. I use Home Assistant to integrate data from my Tesla chargers, my 2 Sense units, from my utility’s net meter and from my Ecobee thermostats to understand how my house is doing. I can share some charts if you are interested.
Big picture is that Home Assistant is an open source (free) home automation platform with hundreds of developer / users contributing code and integrations. I currently use it only for data acquisition and visualization, but not yet for automation (mostly do that in Apple HomeKit). I like HomeKit because it has so many off-the-shelf, ready to go integrations. A few samples:
Shelly and ESPHome offer a wide range of connected sensors, though I use the Sense, Tesla EV, RainForest Automation (Eagle 200) and Ecobee hardware and integrations to pull together all the energy data from my house. You’ll also notice that it is also a meta-platform and can ride on top of HomeKit and SmartThings integration.
Home Assistant Integrations are pre-built to automatically identify and walk you through connecting to each of the platforms / sensors you want to integrate. Once it integrates Home Assistant automatically samples data from all your sources depending on the configuration of each integration (sampling rate is configurable, but defaults are usually pretty good). Home Assistant stores incoming data as entities carrying sensor “state information” and associated attributes over time.
As Home Assistant brings the data in, you can also create calculated state based on functions of the incoming data. Here’s an example where the Tesla EV integration offered up voltage and current, but not instantaneous power and I had to create it.
I have browsed HA’s stuff in the past but hadn’t jumped in because of the lack of use cases that were of high interest to me. However, it looks like it will help solve this question for me.
It’s funny because I have two other projects I’m planning to implement that also suggest setting up a RaspberryPi to run for low-power, always-on use… I guess it’s time to bite the bullet and order one even though they’re pretty deeply backordered.
FYI - Home Assistant recently added a dedicated Energy dashboard that produces views similar to Sense trends, albeit with a more generalized model that includes batteries and with added flexibility since you can use calculations and logic between sensor inputs to generate your inputs to the dashboard…