# Understanding Production Usage To/From Grid

Hi all. My setup: I recently got a solar system (16KW nominal) for my home and got the Sense with Solar setup as part of the installation. The inverters are at the array, and 240v comes back to the house and is connected to the utility incoming 240v service – they called it grid-intertie. The inverters sync with the utility grid, so I can’t run on just solar with the grid being present (no batteries or other power conversion boxes). Sensors are on the incoming solar lines and the incoming utility lines and the Sense box is powered by one of the 240v breakers with a 3rd set of sensors. My WA state utility meter is a net meter, with separate totals for kWh used from the utility and generated kWh returned to the grid. We don’t have Time of Use in WA state, and my utility will give me a 1 kWh credit for each kWh produced over what I consume that I will be used at other times (though I’ve never had a case where I’ve generated more than consumed in a day). My house is all electric, 2 water heaters, electric furnace/stove/oven/dryer, and I charge an EV 1-2 times per week – yeah I know this is a tall order, especially in western WA.

Looking at the Trends / Solar / Usage part of the Sense app, I’m trying to fully understand the Production/Usage/To Grid/From Grid fields and how they are computed.

For example, if I generate 5 kW of electricity constantly for an hour and during that same hour I consume 5kW of electricity constantly for an hour, then would this be what I should expect to see:

Production = 5kWh (read from Solar sensors)
Usage = 5kWh (read from main electrical box sensors)
To Grid = 0kWh (since I am consuming the same amount as producing)
From Grid = 0kWh (since I am producing as much as I am consuming)

Another example. If I generate 2kWh for 20 mins and consume 4kWh over that same 20 mins, then generate 2kWh for the next 20 mins and consume 2kWh over that next 20 mins, then generate 10 kWh for the next 20 mins and consume 5kWh over than final 20 mins. Then, for the 1 hour statistics, I should expect to see:
Production = 14kWh (2+2+10)
Usage = 11kWh (4+2+5)
To Grid = 5kWh
From Grid = 2kWh

That is, Production total is irrespective of whether it’s immediately used or if it is sent back to the grid. And Usage total is irrespective of whether the power used comes from solar or utility.

Is my understanding correct? Thanks.
Mark

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Your understanding and examples are correct. Welcome to the world of Sense.

Excellent, thank you for the confirmation of my understanding.

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