12 of 20 - Energy Storage Operating Modes - Feed-In-Priority

Created by Victor Herrera, Modified on Thu, Jun 9, 2022 at 1:36 PM by Victor Herrera

Please first review the article Energy Storage Operating Modes in order to determine which main mode will be best for you.

Note: Either Feed-In-Priority or Self-use must be turned on but they cannot both be turned on at the same time

Feed In Priority

When this mode is turned on, the system will prioritize selling power to the grid. This means that the battery will not charge or discharge unless Time Charging is turned on and configured properly. Feed In Priority mode is best for people with large PV systems relative to power consumption and battery size. The point of this mode is to sell as much power as possible to the grid and only use the battery for small windows of time or for when the grid power is lost.

This how to set up the system for Feed In Priority mode and achieve peak-rate shaving:

Press the Enter button and then use the Down button to scroll to "Advanced Settings" and then press Enter
The password is 0010 - press Down, Down, Up, and then Enter
Scroll down to "Storage Energy Set" and press Enter - press the Down button once more to "Storage Mode Select" and then press Enter again
Use the Down button to highlight "Feed-In-Priority" and then press Enter, then highlight ON and press Enter
There are two options: "Allow Charge from Grid" and "Time Charge" - first select "Time Charge"
1. Use the Up, Down, and Enter buttons to navigate and make changes
2. "Optimal Income" should say "Run" next to it - if this is set to "Stop" then the parameters in this menu will not be enforced by the system
3. The charge and discharge limits determine how much power the battery is allowed to use or charge with during the time windows that you set. If you set it to the maximum, the system will discharge up to 6kW until the battery is drained to the Overdischarge SOC or the end of the "discharge" time window is reached. Most people will want to keep the charge limit at maximum to ensure that the battery is always charging as quickly as it can when it is charging. The discharge limit is how you can control how much battery power you use on a regular basis.
  1. Maximum limits for BYD B-Box HV:
    1. Charge Limit: 14.3A
    2. Discharge Limit: 12.0A
  2. Maximum limits for LG RESU10H:
    1. Charge Limit: 15A
    2. Discharge Limit: 13.8A
4. Note: the charge and discharge windows cannot overlap with each other
5. Set the Charge Time in 24-hour format (in Hour-Minute to Hour-Minute format)
  1. During this window, the battery will accept a charge
  2. Most likely, this will be set up for hours in which there is sun. If you are using grid power and not PV to recharge your battery, then you would likely set the charge window to match up with the cheapest rate for utility power.
    1. Example: 07:00 --- 14:00
  3. Total time will be displayed on the right in Hours-Minutes
  4. For peak-rate shaving while not using grid-power to charge you should set the Charge Time to be when the sun is shining, so 6AM to 4PM (06:00 -- 16:00) or whenever the peak rate window begins.
6. Set the Discharge Time in 24-hour format
  1. During this window, the battery will discharge power continuously at whatever rate you set it to. The system is not smart enough to vary the discharge rate to match the consumption. Therefore, it is recommended to first determine about how much power is consumed during the hours at which the battery will be discharging. This determines how much power should be allowed to leave the battery during the discharge window.
  2. For peak rate shaving, set the discharge window to match the peak-rate hours
    1. For example: if the peak rate window is between 5 and 9PM then the Discharge Time should be set to 17:00 -- 21:00
  3. Total Time will be displayed on the right in Hours-Minutes
Press Escape and then when "Save and Send" is highlighted, press Enter
It is very important to properly configure backflow power. Please review the article Export Power Set on how to do this.
The system is now set up for Time Charging Mode and will discharge energy during the programmed hours
On the inverter screen there is an arrow between the inverter and battery - this indicates power flow between the two
1. Arrow pointing towards the battery means the battery is accepting a charge
2. Arrow pointing away from the battery means the battery is discharging energy Energy (kW) will be shown above the arrow

The total amount of kWh that can be obtained from a single full charge will increase as the discharge rate decreases.

Therefore, if the battery is being discharged at a rate of 1 kW then it will last for nearly ten hours and close to 10 kWh will be generated from one full charge.