I recently had solar installed along with the Sense Monitor; so far, I really like the Sense.
I got my bill last month and it said I didn’t net any power back to the SCE, but they said they most likely haven’t converted me over to the Solar Net Metering Account and would do so.
Being skeptical, I took a look at my Sense readout and noticed something odd. I was hoping I can get an explanation here to help me understand what’s going on.
From the picture of the last 3 days, It looks like I’m generating a good amount of solar power; 30+ on the first two days and ~25 on the third day when i got cloudy in the afternoon. My usage seems relatively constant with spikes occuring when my 2 fridges kick on. We used the oven to bake dinner on the 22nd and that used a lot of power.
My question is why isn’t the solar lowering my consumption from SCE? I would think that as the array started to generate power, my dependancy on SCE would reduce. And when the array generated more power than my home usage, I would get a negative reading for my usage.
Is something strange going on here with my setup? I just wanted to make sure before another month goes by and I’ve wasted sunny days not backing.
Sense visualization shows ALL house consumption vs. ALL solar production, even though Sense really only meters net usage at the CTs on your mains. It secretly adds the solar back on for visualization and all downstream usage graphs.
ps: I have solar and prefer seeing it this way since I can get my net meter readings directly from my meter - I would rather see full usage and full production.
That view will not show you the net usage. It is showing all solar production, in yellow … and all consumption in red. To see or compare total production vs consumption… go to TRENDS tab, the usage. From there you can look at the data for a day, a week, month or even define the billing period. The Sense data and your power company will never be exact, but I have found it to be dang close.
Thanks for the quick replies. What I don’t get is why why consumption from SCE isn’t being reduced during the day and going negative as power flows from the panels through my box and finally back into the grid.
I was totally expecting my consumption to gradually diminish as the array starts producing power.
Here’s the trends, usage page. It shows the same Trend as the power page.
It’s working perfectly… the graph will not show net. The yellow is solar. The green is consumed. The difference is net. Look at the info below the graph… Usage = 1c. Solar = 3… so you sent 2 to the grid.
If you click on each… it will report kWH produced and consumed, the difference is the net. (Now… in settings , my home… you may need to fill in your approx cost per kWH for the cost to be relevant. (Florida is about 12 cents)
Okay, thanks for the clarification; Sense doesn’t show net energy usage.
This leads me to wonder how sense is actually working with solar. I thought the clamps measure the flow of electricity. So if the incoming solar current was higher than the distributed usage in the home, I would expect the current to flow back through the clamps on the two main hot wires.
How is sense measuring total energy usage when there is incoming power from the solar array? Is it doing the math behind the scenes? If so wouldn’t a net energy usage graph be more intuitive to the end user.
@ketchup318. I believe that most customers are concerned with total energy consumption and total solar production. The monitor does indeed do math to display those characteristics. Most of us would find it harder to visualize actual consumption if the monitor displayed net usage. Most utilities have customer web interfaces that can show you your net consumption at a glance. The actual consumption C/T’s measure bi-directionally so true consumption and solar can be determined. Hope that answers your questions.
As to “how” I don’t know - I just know it works. I also know the accuracy of production and consumption data beats the Enphase Enlighten data that I also have from my Solar installation hands down. My Enlighten app does have a net power graph - but have to say it is not very good.
As for a net energy graph - in my opinion, it might make a nice addition - but not as a replacement to the info available now. Keep in mind that Solar is an optional add on so not every user has it. The primary purpose of sense is to try to track and manage individual usage loads. Anyway there is a section here on this forum to request new features - give it a shot.
I don’t know your background, but I prefer to see the two independent variables displayed in a graph rather rather than seeing a combined function of both (net power), especially since my utility and power meter only show net metered usage. Much easier to take aim at Total Usage when you can see all of it.
One thought to bear in mind - if the meter to your house is NOT a bidirectional meter, then current flowing EITHER way will register as power you consumed…
I have a solar inverter that provides 100% power to my house regardless of if its coming from utility or from DC being generated by solar panels. So it keeps a balance, the more solar DC produced less AC requested from the Grid.
When Solar DC exceeds house loads it is transformed to AC and exported back to the Grid through the same AC Input to the Inverter (reverse direction)
I installed the SENSE CTs on the AC output of the inverter so it detects all the loads and its working fine. I was thinking about upgrading my SENSE to “solar” but installing the CTs on the AC Input of the Inverter. This would allow me to know how much of my total output is coming from the utility…
Buy what would happen when flow is reversed because im exporting to the grid?? Is that flow going to be reported as negative? CTs work bidirectional?
I would be using the “solar” CTs to measure AC From/To the Grid…
@ramon.fardonk the way you described your solar inverter doesn’t sound correct. Your solar inverter converts the DC from the panels to 240V AC and drives that into your main panel. If your house’s electrical load is less then the power produced by the inverter, the extra current flows out back through your meter into the grid; if your house’s electrical load is more than the power produced by the inverter, some additional current will need to flow in from the grid through your meter. Electricity from the grid with not flow in through the inverter to your house’s loads.
The Sense main CTs on your panel’s mains will detect current going in both directions. The Sense solar CTs on your inverter do too, but when the solar is producing power, the current through the solar CTs will always be going one direction, irrespective of your house’s loads at the time. (When solar is not producing, a very small amount of power will be consumed by the inverter itself…this is when the Sense solar CTs will see current flowing in the other direction.)
Regardless of the direction of current flow through the main and solar CTs, Sense will do some quick math under the hood and always display the consumption (house loads) and production (solar generation), each as positive values.
Interesting inverter. It also is a charger (AC to DC for battery changing), and is also a transfer switch (60A for a critical loads sub-panel), and is also an islanding inverter.
How do you have it hooked up? I assume the following:
Grid hooked up to main panel.
Main panel has most house load circuits.
Main panel also has connection to “AC1” of your inverter.
“AC2” of your inverter hooked up to backup generator. (You haven’t mentioned this; you may not have this hooked up.)
“ACout” hooked up to a critical load sub-panel that services the other loads of your house.
Assuming this is how you have it hooked up, I don’t think Sense, with solar, supports this configuration, because there is no single place to monitor the solar AC production, unless you have nothing connected “ACout” and rather only use its AC1”.
If you do have a critical loads sub-panel on “ACout” and you have the Sense solar CTs on “AC1”, then Sense will report solar production being the actual production minus the critical loads consumption…you would not want this. As an example, if the solar/inverter was actually generation 5kW and the criticism load sub-panel was consuming 3kW, the Sense solar CTs on “AC1” would only see and report 2kW; if the solar/inverter was actually generating 1kW and the critical load sub-panel was consuming 3kW, the Sense solar CTs on “AC1” would see and report -2kW…you would not want this.
Thinking about this configuration some more, if you could get the Sense solar CTs to wrap around both “AC1” and “ACout” wires, then Sense solar would report the solar generation correctly.
Anyway, I’ve been assuming you have this inverter hooked up in a particular way that could be wrong. Please describe how you have it hooked up in relation to the grid and all the loads in your home.
How do you have it hooked up? I assume the following:
Grid hooked up to main panel.
Main panel has most house load circuits. - YES
Main panel also has connection to “AC1” of your inverter.- YES
“AC2” of your inverter hooked up to backup generator. (You haven’t mentioned this; you may not have this hooked up.) - YES
“ACout” hooked up to a critical load sub-panel that services the other loads of your house. - YES
SENSE CTs are hooked here at AC Out. Detecting all appliances and showing all Loads.
There is NO AC coming from panels. The Charge Controller MPPTs receive DC from panels and store it in the batteries. So my AC Out comes from, if required, AC In + (XW6848 DCtoAC).
When My DC From panels exceed my Loads, NO AC-In (Grid) is used
Loads (AC Out) are covered, and the remaining DC is converted to AC and send back to the GRID through AC-In… and it becomes a credit to my Bill.
So if i install SENSE Solar CTs at
AC-In… It will count AC that flows there From or To the Grid.
AC-Out (Loads) = (XW DCtoAC) +
(AC-In-Grid If Needed)
AC-InGrid —> Through Solar CTs
—-> XW AC-In —-> Counts Positive?
AC-InGrid <— Through Solar CTs
<—- XW AC-In “DCtoAC” <—- Counts Negative???
< Sent From Mobile >
Ramón Fardonk
[Personal contact information removed by moderator]
If you have the Sense main CTs hooked to “ACout”, then they won’t see any current going to any of the loads in your main electrical panel, rather they’d only see the current going just to the loads from your smaller critical loads electrical panel. You need to have you Sense main CTs in your main electrical panel on the mains to/from the grid, so that they sense any current that is going to any and all of your loads (minus what solar/battery is helping).
Then like I said in my previous response, to get the solar reporting right, you’d need to put the Sense solar CTs around both the “AC1” and “ACout” wires.
Sense then automatically calculates:
"usage" current = main CT current + solar CT current.
"production" current = solar CT current
If you put the Sense solar CTs on “AC1” only, then Sense will only see your solar production minus whatever load your critical sub-panel is consuming at the time.
Yes, both the Sense main and solar CTs can detect positive or negative current. But again, I don’t think you should have the CTs hooked up the way you describe, but rather should have them hooked up the way that I’ve described.
