You’ve gone solar! It’s an exciting time and you have made a great financial decision. When you first get your solar system up and running and get your first utility bill, it can sometimes be confusing. You see numbers on your meter, numbers on your utility bill, and numbers on your inverter or monitoring system. How do you make sense of it all? In this blog we will use an example to explain the difference between these numbers and how to better understand your utility bill with your new solar system.
Inverter or Monitoring System
Our customers first interaction with their solar production is usually by looking at the inverter directly, or monitoring their solar systems production via an online monitoring systems. The numbers you are seeing from the inverter reflect only the production from the solar system. The inverter numbers do not show how much power you’ve used nor do they show the amount of power that you’ve fed back to the grid. The number you see on your inverter is total solar production in kWh for the day, week, month, or year. These are exciting numbers to watch, however you will not see these numbers on your utility bill or on your utility meter, because both of those sources only interact with power that you’ve used from the grid, or power you’ve pushed back on the grid for credit.
If you are one to read your own utility meter, you will notice that once your net meter is installed, you will see the meter cycling through different numbers. You will see a number with DEL and a number with REC. The meter is always in the perspective of the utility.
DEL stands for electricity delivered to you from the utility.
REC stands for electricity the utility has received from you (the excess solar power that you’ve produced but not yet consumed).
These are lifetime numbers so if you want to know your total DEL or REC for that year or month, you will have to look at your numbers from a previous utility bill. Below is an example of a utility bill and how to calculate and understand your electricity consumed (DEL), electricity generated (REC) and your electricity credit (DEL – REC).
Below is an example of a utility bill for a net metered customer. It begins with the electricity consumed. It shows the actual meter reading from June 24th (838 kWh) and July 25th (1400 kWh). The difference is the electricity consumed over the course of the month of July (562 kWh). On the meter, the electricity consumed shows up as DEL which stands for delivered. The electricity delivered from SaskPower to you.
1400 kWh – 838 kWh = 562 kWh
Next is the electricity generated. This is not the total amount of electricity your solar system has produced. This is the electricity that has been fed back to the grid – the additional electricity that was produced by your solar system. It shows the actual meter reading on the generation side from June 24th (1337 kWh) and July 25th (1917 kWh). The difference is the electricity that was fed back to the grid over the course of the month of July (580 kWh).
1917 kWh – 1337 kWh = 580 kWh
Below that you see Previous generated electricity – this is the balance of your net metering credit from the past month. Net electrical consumption/generation is the new balance. So in the case of this bill, the difference between the electricity consumed and electricity generated is the amount of change in the credit amount.
Electricity generated (580 kWh) – Electricity consumed (562 kWh) = 18 kWh
Previous generated electricity (499 kWh) + difference between consumed/generated (18 kWh) = 517 kWh which is the new credit total with the utility.
Total Power Used in the Home
Understanding how much electricity your home actually used in a particular month or year given all of the information and numbers described above can be a bit tricky. Check out our video to understand how to read your new power bills: Understanding your utility bill with solar.