Electrical bills seem to be too high

[voyager]

We had our solar panels installed in November of 2014.
The installation was of 16ea 280watt panels giving us what I figure as a 4.5 Kw installation.
We are grandfathered into a net metering account with HELCO, the electrical supplier here on Big Island.

For the first year or so, we almost never had an electrical bill from HELCO for more than the minimum charge for being connected to the net ~$20/mo.
Then, for the last year, year and a half or so, our bills began to climb.

I just compared HELCO's numbers for what our installation has produced to what The Enphase website says our installation has produced.
For the last year, February, 2017 through February, 2018, Enphase says our installation has produced 6,228 KwH.
HELCO's latest bill shows our production for reading dates 3/13/2017 thru 3/13/2018 as being 4,907 KwH.
That is a 1,321KwH discrepancy between the two reports.

Am I missing something.
Or, is HELCO missing something?

To my thinking, the two numbers should be reasonably close to each other.
I have heard something somewhere about smart meters having some problems with accuracy.

Any info that might explain this, or confirm the discrepancy being due to inaccuracies would be appreciated.

[J.P.M.]

First, does your POCO report what you produced or what you drew from them ?

How do they know what your system produced. ?

After that:

What has the Enphase system shown for production for comparable calendar periods over the last 3.5 years ?

Any substantial changes in annual yr./yr. production greater than, say, ~ 5-10 % or so ?

Has the way the POCO charges you for power changed ? Lots has been happening in tariff reform over the last few years.

After that, Any changes in your appliances ? Has your usage gone up/down from lifestyle changes ?

All the appliances operating nominally ?

Any appliances left on unknowingly ? A 150 Watt bulb/appliance left on will burn ~ 1,321 kWh/yr.

Any trees and shading over ~ the last 3.5 yrs. ?

If you can't make sense of it on your own, and if you, like most folks, have a system under warranty, call the installer. That's part of what you paid for.

[ButchDeal]

Poco does not know what you produced. They just know what you sent to them. Inverters know what you produced.
the difference is your self consumption in the home.

[voyager]

Thanks for your responses guys.

This is getting more complicated than I had expected.
I've pulled all the electrical bills for 2014 through 2017.
Plus, the 1st bill for 2018, .the one that brought the question to the forefront of my mind again.
These bill run from before the solar installation was made to the present.
I've been making scans of the bills.

It seems that there is no direct correlation between the bills and Enphase's production numbers.
Plus, seasonal weather variables will need to be accounted for.
The last year and a half to 2 years have been cloudier and wetter than the first two.
Then. HELCO seems to do an occasional adjustment to the billing, sometimes more is owed, sometimes a credit is given.
The present bill may be one of those adjustments.

Enphase has an online graphical type of record of production by day, week, month and year since the installation went online.
I probably should get NWS records of the solar intensities for our area, if their is such a thing available.

I am attaching a redacted PDF copy of our December 2017 bill.

December 2017.pdf

Does it contain enough information to compare to Enphase's output info?

Are solar radiation intensity records available and accessible?

Is it possible that Enphase's information is available in a form other than the graphical form found online?

Am I simply playing Don Quixote?

[J.P.M.]

Thanks for your responses guys.

This is getting more complicated than I had expected.
I've pulled all the electrical bills for 2014 through 2017.
Plus, the 1st bill for 2018, .the one that brought the question to the forefront of my mind again.
These bill run from before the solar installation was made to the present.
I've been making scans of the bills.

It seems that there is no direct correlation between the bills and Enphase's production numbers.
Plus, seasonal weather variables will need to be accounted for.
The last year and a half to 2 years have been cloudier and wetter than the first two.
Then. HELCO seems to do an occasional adjustment to the billing, sometimes more is owed, sometimes a credit is given.
The present bill may be one of those adjustments.

Enphase has an online graphical type of record of production by day, week, month and year since the installation went online.
I probably should get NWS records of the solar intensities for our area, if their is such a thing available.

I am attaching a redacted PDF copy of our December 2017 bill.

[ATTACH]n373104[/ATTACH]

Does it contain enough information to compare to Enphase's output info?

Are solar radiation intensity records available and accessible?

Is it possible that Enphase's information is available in a form other than the graphical form found online?

Am I simply playing Don Quixote?

You need to learn and understand more about how your system works and also how you are billed for power. Until you do learn more your confusion will continue. Little of it is a straight line process.

The solar generation process, and what a system produces is, just like the weather, a chaotic process. Best loose analogy may be that a system's long production estimates will tend to follow local climate over the long term and daily output will tend to follow the weather. Climate's what you expect and weather's what you get. This is not an exact science.

Until you understand your POCO's billing system in some detail, you will not get a firm grasp on how it's foibles and intricacies will interact with your system's generation (and the weather) and your usage patterns to produce a bill. There are ways to what you and many folks seem to want, but none of them are as straight forward or simple as might be desired.

Your bill looks pretty straight forward. I'd learn what each billing item is, where it comes from, what it means and what can make each item change. For example "Customer charge" of $10.50 is probably a per month base charge and may change with a rate adjustment. "Base fuel energy" is probably based on your net monthly use in kWh times some per kWh rate for the actual commodity (the electricity). "Non fuel energy" may be some form of per kWh charge to maintain the systems that get the power from where it's generated to where it's used (lines, power poles, substations, admin., etc.). Some of those charges may be per cust. while others may be on a per kWh delivered basis.

Understanding how you are billed will go a long way down the road to understanding how and why billing changes month/month.

You have kWh 3 numbers: What your system generates, what the POCO sends you, and what you send back to the POCO. What you generate and what you send back to the POCO are different numbers. As Butch writes, the POCO has no clue about what your system is generating. They only know what they send you and what you send back to them. Your Enphase meter and the POCO meter do not communicate.

If you want to compare your system's output with that of nearby systems check out something called "PVOutput" (PVOutput.org). Look for systems near you with similar orientations (Different orientations will give different per kW system size outputs).

Solar irradiance records are usually not available. Models exist ( see something called the "TMY manual"), but that data is NOT for the most part record data. Most of it is synthetic and modeled. See the manual for details, but remember, it is not a record of past data of the type and format you may have come to believe.

Not for me to say if you are playing Don Quixote, but if you take the time and make the effort to understand, you'll clear up a lot of your confusion. Whether or not the effort is worth the payoff is something only you can determine. The answers are there for those who look. You can get to understand and nail your bill within a few pennies if you choose.

This isn't a knock, but Most folks don't understand the effort required to do it right and correctly, or that there is not a one line answer.

[voyager]

Thanks people.
Your responses have helped to clear up my thinking on how to go about this.
I have found HELCO's PDF explaining their net metering billings.

I have also found out how to get a spreadsheet summary of Enphase's daily production on a monthly basis.
That should also give me a very good idea as to how the solar radiation has varied on a daily basis.
After downloading all 36 of the spreadsheets, I should be able to generate a graph that will show any trend towards lower output.

The previous month's billing [Nov 2017], as shown on the attached bill, of $90+ is about 1/2 of what we were paying monthly before having the solar installation made.
Our bills seem to have been creeping upwards for over a year now.

After we added the solar array we were getting the minimum $20+ monthly bills regularly.
Now it is a rarity when we do.
If we add more panels, we'll lose our NET metering status.
The newer replacement metering systems are not as generous in their compensation of the array owner.

I am considering cutting the cord by adding a few more panels, and batteries to our setup.

Before doing something like that, I need to have a more complete understanding of how the present situation is working.

Our panels are 280 watt Solarworld panels.
I assume they are good quality panels and should not have lost much efficiency in the 3 years they have been in use.

[J.P.M.]

Thanks people.
Your responses have helped to clear up my thinking on how to go about this.
I have found HELCO's PDF explaining their net metering billings.

I have also found out how to get a spreadsheet summary of Enphase's daily production on a monthly basis.
That should also give me a very good idea as to how the solar radiation has varied on a daily basis.
After downloading all 36 of the spreadsheets, I should be able to generate a graph that will show any trend towards lower output.

The previous month's billing [Nov 2017], as shown on the attached bill, of $90+ is about 1/2 of what we were paying monthly before having the solar installation made.
Our bills seem to have been creeping upwards for over a year now.

After we added the solar array we were getting the minimum $20+ monthly bills regularly.
Now it is a rarity when we do.
If we add more panels, we'll lose our NET metering status.
The newer replacement metering systems are not as generous in their compensation of the array owner.

I am considering cutting the cord by adding a few more panels, and batteries to our setup.

Before doing something like that, I need to have a more complete understanding of how the present situation is working.

Our panels are 280 watt Solarworld panels.
I assume they are good quality panels and should not have lost much efficiency in the 3 years they have been in use.

Going off grid is always an option. However, most folks don't know that doing so will increase the per kWh cost of power by maybe an order of magnitude or so. On top of that, most folks have no idea of the lifestyle changes that are usually and commonly necessary.

Bottom line: Look before you leap, then look some more and don't believe all the rose colored scenarios you'll read about from those with stuff to sell you. It ain't all sweetness and light - not to mention another part time job maintaining your own electrical system.

[voyager]

Just to update this thread.
After happenings discussed in my other threads, HELCO installed a new meter before we moved back into our home after the evacuation.
Our usage is now much more reasonable.
I think we were victims of "smart meter error" over charges.
It's too late to chase it down now.
But, we will watch it closely in the future.