Why does my utility bill show I am producing less than my SolarEdge dashboard shows?

A customer recently asked this question, concerned that the utility was not giving her full credit for what she was producing.

The quick answer is that not all of the energy the array produces is exported to the utility grid. Thus the amount shown on her utility bill was only the amount of energy produced less the amount consumed in her home.

For a fuller explanation, read on...

Solar Array & Utility Interconnection.jpg

There are a few numbers to consider when evaluating your solar array:

  • the energy you consume in your home or business,
  • the energy you import from the utility,
  • the energy your solar array produces, and
  • the energy you export to the utility grid.

The energy you consume is the total energy required to run all the electrical appliances in your home or business, whether you had a solar array or not, regardless of the source (the utility or your solar array).

The other three numbers vary depending on a number of factors including your demand, the time of day, and how clear or cloudy the weather is.

When your solar array is producing energy, all of that energy goes to powering your home or business, first. If your array is producing more than you need, then the excess charges a battery system, if you have one, and the remainder is sold to the utility. That is the amount of energy you export.

During times when your consumption is greater than the energy produced by the array, such as late in the day, at night or during cloudy periods, your system will import the energy needed from the grid to meet the consumption demand.

Some utilities show only the net amount you import on your bill. If you export more to the grid than you import. the bill usually shows zero, and the utility keeps track of the amount you exported for later credit.

Other utilities will show the amount you imported separate from the amount of energy you exported. These utilities provide a transparency that many customer prefer.

This customer asked why the export amount shown on the utility bill was lower than the total production for her solar array. In her case, almost half of what she produced during the billing period was exported to the grid. The rest was consumed in her home.

Feel free to follow up with comments or send any questions to us via the Contact Us link at the top right of this page.

Product Review: SolarEdge Consumption Meter

Your SolarEdge inverter and the SolarEdge monitoring portal dashboard provide you with information regarding your energy production. These do not show you the energy you are exporting to your electrical utility, nor detail your consumption.

Some utilities will provide you the amount of energy you imported from and exported to the grid during the billing period. Other utilities only provide the net amount you imported from their grid or zero, if you exported more than you imported.

If you are like some of our solar customers, you’d like to have your own source of this information to compare to your bill.

Below is a review of the first of three solutions for you to consider.

NOTE: As always, it is best to read multiple independent reviews before deciding on one of these products.

 

SolarEdge provides a consumption meter that adds the ability to track

  • the energy you import from the utility,
  • the energy you export to the utility,
  • your total energy consumption regardless of the source of the energy, and
  • your self-consumption, the amount of energy you consumed that your array produced.

The advantages of the SolarEdge option are

  • it is fully integrated into the SolarEdge monitoring portal, displaying the above information on the dashboard (see the illustrations below),
  • it interfaces seamlessly with your SolarEdge inverter, and
  • there is the ability to add or remove information from the graphs for clarity.

The diagram below shows a view of a full month of production at a glance including Consumption (in red), Solar Production (in green) and Self-consumption (in blue). The graph below shows energy imported (from the grid) and exported (to the grid).

 SolarEdge dashboard view with Consumption Meter

SolarEdge dashboard view with Consumption Meter

If you want to look at a single day at a time, you can see more detail. There are numerous options for displaying this data, even adding and removing categories of data. The information at the top of this image show that, of all the energy produced, 73% was self-consumption and 27% was exported to the grid. Of total consumption, 25% was produced by the array and 75% was imported from the grid.

The graph below shows information in 15-minute intervals. For the data shown here, it was a rainy day, so production was rather spotty. At times production was greater than consumption (green area higher than the red and blue). Early and late in the day, consumption rose well above production.

 Daily consumption meter detail.

Daily consumption meter detail.

The disadvantages of the SolarEdge option are

  • it does not show what devices in your home are consuming energy,
  • the SolarEdge Meter takes up some wall space near your inverter,
  • the only app interface provided is the SolarEdge Monitoring app,* and
  • installation and configuration really should be performed by an electrician or solar professional.

Feel free to contact us using the link at the top right above.

Rob Walsman
Solar Asset Manager

Net Metering and You

Net Metering and You

Net metering allows you to save money directly following the completion of your installation. Once your panels start feeding energy into the grid, you receive credit for it and you only pay for net energy consumed.