To model your interconnected mini-grid in Odyssey you have three options depending on your agreement with the DisCo region and desired plan:
- Modeling a mini-grid that consumes from and optionally exports electricity to an unreliable grid
- Modeling an islanded mini-grid with no grid consumption or export
- Modeling a mini-grid with designated grid feed-in/export periods using HOMER Pro
Option 1: Modeling an unreliable grid
If you are planning to interconnect your system to the main grid and expect the grid availability to be unreliable, you can include the grid component from the schematic. In the component, you can specify whether both purchasing electricity and selling back to the grid are allowed. If you are planning to sell electricity to the grid, electricity revenues are calculated using a net-metering scheme, which calculates the grid electricity expenditure at the end of the net-metering payment frequency (monthly or annually). This figure can be negative if your revenues from selling electricity are higher than the costs from consuming electricity.
You can also specify if the grid is unreliable (not available 24 hours a day), and how many hours it is available during the daytime (6:00 - 18:00) and nighttime (18:00 - 6:00). The specified Daytime Availability and/or Nighttime Availability hours are distributed randomly over the 12-hour period to simulate grid unreliability.
Option 2: Modeling an islanded system
You can model an islanded system in Odyssey using HOMER by not including the Grid component from the design schematic at the top of the page. This is a good option if you don't want to consider/rely on grid power in generation system sizing.
If you are modeling an islanded system, do not drag the Grid component down into your Generation Design. Proceed to Step 6. Enable/disable HOMER Optimization.
Option 3: Modeling a designated grid feed-in/export schedule using HOMER Pro Desktop application
You may use the HOMER Pro desktop application if you have agreed upon a more detailed grid export agreement with the DisCo. This would be the best option if you have agreed upon time slots where the DisCo has agreed to feed-in electricity to or receive electricity from the mini-grid.