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Electric Bills Not Matching Reporting (Not even close)

Electric Bills Not Matching Reporting (Not even close)

On the app over the last month I have an offset of 98% and somehow my electric bill came to $35 and we ate 200kWh of our credits.

My issue is that the electric company only sees what we overproduce so when I call and ask them to check if the meters bad, they just give me the run down on how the system works.

Here are my total numbers since the beginning of the system (April 2019):

4649kWh - Home Usage
6020kWh - Solar Energy

2755kWh - From Grid
4127kWh - To Grid

Seeing these numbers, how do I owe on my electric bill and not have credits?

edwardneal2222 | 5 augusti 2019

I would recommend you call both Tesla and your utility to find out whats going on. If I am not mistaken Tesla does not read posts here and without knowing the specifics of your system install agreement and you utilities NET metering plan and billing methods no one here will be able to give you a specific answer.

Tampalacrosse | 9 augusti 2019

Okay so what threw me off is "Home Usage" not the actual home usage, I really don't even understand what the point of this is. Duke said we used 1720kWh and Tesla Home Usage says 1270kWh.

Does anyone know what the point of the Home Usage section is?

Ben in CT | 9 augusti 2019

The first response is absolutely correct: you need to get out there and understand your net metering agreement and figure out exactly how Duke energy records usage and credits. However, your numbers actually make perfect sense: The numbers reported by the Tesla app are the actual numbers, both for home usage and solar production (you should be able to verify the latter by checking your inverter). Duke is only reporting NET numbers -- they have no visibility to anything that your panels produce and your home consumes immediately. So, over the period in question, your system produced a net surplus of (6020kWh solar production - 4649kWh home usage ) 1371kWh. Duke, from what they saw flowing through their meter (only the amounts that were excess to your immediate production / consumption) was ALSO a surplus of 1372kWh (4127kWh from your house -2755kWh to your house). HOW that excess production and credits are handled is a function of your net metering agreement -- and you probably have a periodic true up built in there somewhere when you may have lost some credits or had them paid out in a statement credit. Now, the "monthly" numbers are NEVER going to tie out unless the reporting periods are exactly the same, and unless the Tesla app someday gives you the capability to display a custom reporting period, they probably won't ever coincide with the dates on your electric bill. As far as the $35 goes, check your bill for flat rate charges, fees, taxes, etc. I pay Eversource $9.65 every month for the privilege of being connected to their wires, whether my solar covers my production or not.

Tampalacrosse | 9 augusti 2019

Hey Ben, Thank you for your reply. The Inverter numbers match perfect to the Tesla reporting however the home usage is what took me for a spin as it does not actually record/let you see the full picture. My Duke bill for July was the billing period of July 1-July 31. As Duke states "The solar app reports only what was generated from solar and consumption from Solar- and NOT what was used from Duke Energy."

From Tesla:
Hope this email finds you well. Here is the information you requested regarding system production.

July - Solar Production

7/2019

1,279.530

Consumption for July

07/2019: 1296.3

From Duke:
As requested, here is a follow up of our conversation. On the July bill, it shows there was 216kwh remaining to carry to August bill. On the August bill, it shows 953kwh used from Duke, and 512kwh given back from solar. The solar app reports only what was generated from solar and consumption from Solar- and NOT what was used from Duke Energy. With efforts of making sure that the bill was calculated correctly, we completed this equation together…. 1279 (the amount generated) – 512 (unused excess energy) = 767kwh of solar used in the home… We then add 767 to 953 = 1720 (the total amount of energy used in the home. If you were not on solar the amount of energy charged would be 1720 kwh. Now, if the total amount of generation went towards the total consumption, 1720-1279= difference would be 441.. Then subtracting the kwh from July (441-216) = 225kwh billed net difference.

For more details on Net Metering Billing- Please reference https://www.duke-energy.com/home/products/renewable-energy/generate-your...

Patrick | 11 augusti 2019

Tampa - just commented on the other related thread before seeing this one.

If your July generation really was 1.28 MWh and consumption was 1.29 then your system is likely running well. Assuming that data is correct, Duke would have provided the difference of roughly 0.01 MWh or 10 kWH of energy in July, and should have subtracted that amount from your running net-metering balance.

I didn’t try to follow the math in their email but the numbers don’t seem to add up....

FWIW - We have found it difficult to reconcile our actual generation and consumption numbers with those shown on the Duke statement for any given month and we gave up trying. All we know for sure is our generation roughly matches our consumption on an annual basis (like your July data indicates, if correct) and we are rarely charged for pulling any extra energy from Duke.

We’re not using a Tesla system in this home so I can’t comment on the accuracy of their data here, but they use the same Neurio monitoring technology internally. Our Neurio data is accurate.

Tampalacrosse | 13 augusti 2019

Patrick - Yes thats how I thought it worked until Duke explained (or at least claims) the Tesla app can only see what energy is used from Solar, not what the actual home uses. I called Tesla and they confirmed that is accurate. Which is why I asked, whats the point of home usage if it cant get me what the actual home usage is?

Tampalacrosse | 13 augusti 2019

I should add to this thread I am solar only, no powerwalls.

Patrick | 14 augusti 2019

That’s definitely how it works.

Now I’m confused - thought you were referring to the Tesla app used with Powerwalls. Not sure which app you are referring to, but many inverter monitoring apps do not measure actual home energy consumption. That’s why we installed the Neurio monitor which accurately measures both generation and consumption.

Tampalacrosse | 19 augusti 2019

So Tesla reached out looks like its a registration issue thats being escalated to tier 2 support now. I will add updates here incase anyone else runs into this issue in the future and can save themselves months of phone calls.