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how is "Surplus Electricity Going To Utility" calculated?

asked 2017-12-05 03:48:46 -0500

oat's avatar

updated 2017-12-05 15:12:34 -0500

May I ask how Surplus Electricity Going To Utility is calculated as reported in the Electric Loads Satisfied table in the html file ?

May I also ask why Net Electricity From Utility is not equal to Electricity Coming From Utility minus Total On-Site Electric Sources?

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Please tag with the specific software you're using if appropriate (energyplus here), and do not include greetings (thank you, hello, etc), per our convention. Thanks!

Julien Marrec's avatar Julien Marrec  ( 2017-12-05 09:05:06 -0500 )edit

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answered 2017-12-05 08:56:55 -0500

updated 2017-12-05 09:02:10 -0500

At times your On-Site production is exporting to the grid because it is higher than the demand it needs to cover.

So in all, you bought from the Utility 1,436,312 kWh, but you also exported 6,236 kWh, so the Net is difference between the two, so 1,430,075 kWh.

If you didn't have On Site production, you would have bought 1,430,075 kWh + 284,130 kWh = 1,714,205 kWh.

Check out the Engineering Reference for Whole-Facility Electric Service

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Thanks, Julien. The table shown above is for a scenario in which we have "on-site production" through PV, if that is correct. So, should the net purchased electricity in this case be "1,430,075 = 1,714,205 - 284,130" (in kWh)?

oat's avatar oat  ( 2017-12-15 23:40:35 -0500 )edit

@oat: the equation you wrote is exactly the same as in my answer, except the 284,130 was moved from the left to the right of the equal sign ;)

Julien Marrec's avatar Julien Marrec  ( 2017-12-19 03:41:51 -0500 )edit

Yes, Julien, you are right. I think I misread your comment and thought you were saying that 1,714,205 is the number for "you would have bought".

oat's avatar oat  ( 2017-12-19 06:19:48 -0500 )edit

If that solves your problem, remember to mark the answer as accepted so the thread can be identified as resolved. Thanks

Julien Marrec's avatar Julien Marrec  ( 2017-12-19 08:16:08 -0500 )edit

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Asked: 2017-12-05 03:48:46 -0500

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Last updated: Dec 05 '17