# Understanding Solar Production and Usage

Can you post screenshots similar to the pictures I uploaded?
solar
&
dashboard → “view detailed”

Then we can explain using your own data

@dannyterhaar ,
@fred2g did post one screenshot mid way down the topic. I answered based on his data. The bottom line is that he used substantially more electricity than solar was producing in the AM (from grid) and then produced lots of excess electricity in the afternoon and exported to the grid.

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OK, here are screenshots of May 9th. Hope they are clear enough.

From the Solar Page:

and from the Dashboard Page:

I hope it explains what you are looking for. I’m doing all this on a PC, as I do not like nor understand the tablet operation.

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like Kevin said:
On that particular day, your PV system directly (without aid from the grid) powered 56% of your home. So 44% was coming from the grid (when there was not enough solar)
Over the whole day, including what you stored in the grid, your solar generated 120% of what your home used that day.

How do you figure that? Both windows show the same day, and the same production (31.9kWh) and the same usage (26.5kWh).

The data is for the day, 24 hours, so the math should show the same percentage, by my reckoning.

This is giving me a headache.

One visual way to look at it = Total Usage is the sum of the green bars. Power by Solar is the sum green bar length where there is orange bar to support it. And when the orange exceeds the green, you only get to count the length of the green. Because we’e only counting how much of the green is supplied by the orange, divided by the green, you can see that the best you will ever do is 100%. But to do that, the orange has to be equal to, or exceed the green for every hour in the day (not possible, except if you are using batteries to shift excess solar in time).

Once again, this is important, because solar production sent to the grid is often not as valuable as solar production you directly consume, plus is subject to the vagaries of how your utility wants to pay you for it.

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Look at your energy usage & generation between 11:00-12:59

During those 2 hours your house used more electricity than the solar generated.
What you were lacking from SOLAR was provisoned by the grid.
There was no 100% coverage of solar at that point.
Also all energy usage before sunrise and after sunset did not come from solar.
So 100% “powered SOLELY by solar” is impossible unless you have batteries.

Over the whole 24 hours your solar generated 31.9 kWh, while your usage was 26.5kWh
31.9/26.5= 1.20377 with a small rounding is 120.5%

Hopes this explains it.

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Thanks guys - I do think I have it now. It doesn’t seem to me to be a very useful figure - but then I get the same rebate from the utility company as I pay for the power. I understand others do not, so Sense probably tried to make their program cover ALL possibilities.

New instructions based on all this is being written right now, hopefully to help others who cannot see the light.

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