HOMER Energy Support

Getting Started with HOMER Grid

Last Updated: Feb 28, 2018 04:01PM MST
HOMER Grid is a robust, powerful tool for optimizing the value of behind-the-meter, distributed generation systems, especially when demand charges and energy arbitrage matter. This article is a quick guide to help you get started with your first project.

The quickest way to get up and running with HOMER Grid is with the Wizard. Click ‘Start Wizard’ in the upper right. The Wizard will take you step-by-step through defining a location, electricity consumption, and utility tariff. The Wizard will automatically consider solar and storage and incentives for your system.

1. Setup your project

When you open HOMER Grid, you will find yourself in the ‘Setup’ window. From here, you can define the project location, give the project a name, give your model an author, set some basic descriptions of your model, and set some basic model inputs.

You can set project location by dragging and dropping your location pin, clicking on the map to drop a location pin, or typing an address into the ‘Search Location’ field.

Setting the location give you easy access to the solar and temperature resources (via the ‘Resources’ button above the map) and allows you to quickly find a utility tariff for your location. 

2. Navigation

Navigate HOMER Grid with the tree menu on the left. 

A system schematic will appear as you build your model.

Required Changes will be visible at the bottom of the window, which provide guidance about inputs that you will need to provide as you develop your model.

3. Define your electric load

Imported load data will ensure the most accurate results. You will need twelve months of data, in time-steps from 1-minute to 1 hour.

If you do not have measured interval data to import, HOMER Grid can still help you to create a reasonable electric load. You can use a generic load profile from the OpenEI database, or you can choose from one of the synthetic load profiles, displayed in the thumbnail graphs.

Click Ok to add the electric load to your model.

4. Define/identify your utility tariff

Click the Utility button, located under Components in the tree menu. A tariff is the set of rules and costs for buying and selling electricity from a utility. Your postal code will be used to pre-populate HOMER Grid with potential tariffs. HOMER Grid tariff information comes from Genability, a trusted third-party platform, which offers tariffs throughout many parts of the world. Currently, HOMER Grid contains Genability tariffs for much of North America, Mexico, Canada, and Australia. 

Click the ‘Get Tariffs’ button to see the tariffs available in your area.

Select a tariff and click Ok.

5. Check that your tariff and load match your monthly energy bill
If there are any special rate settings required for your tariff, you will see them listed, and you will need to enter these for your project.

Click on the button, ‘Visualize Bill and Tariff’ to see a bar chart of your monthly electrical bill. The Consumption Rate and Demand Rate heat maps show you during which seasons and what times of the day your energy and demand charges are highest.

Double-check that your energy and demand charges match your current electricity bills by comparing your monthly bills to the stacked bar chart in HOMER Grid that shows energy expenditures per month.

Check that the tariff is approximately represented by the heat maps for consumption and demand rate to the right. Each of the heat maps present an entire year of data, with the day-of-the-year on the horizontal axis, and the hour-of-the-day on the vertical-axis. For each hour of the year, HOMER Grid displays the color from the color bar on the right-side of the heat map. Hover your mouse over the colorful heat maps to see your energy and demand charge for a particular time step.

6. Consider additional tariffs (optional)
You may have the option of other tariffs to serve your load. If you would like to try additional tariffs for your distributed system, you may add a second or third utility tariff. Click the plus symbol and repeat steps 4 and 5.

7. Consider adding solar PV to your system
If you want to see system options with solar PV, navigate to PV, located under Component in the tree menu. You can select a PV module from the Quick Pick dropdown menu, or you can consider many other PV module options by clicking on the Complete Catalog button.

Once you have selected the PV you would like to consider, click “OK” to continue.

8. Sizing and optimization options in HOMER Grid
For many components, such as PV, you have very fine control over how HOMER Grid sizes your system. The HOMER Optimizer will automatically find the most economic size by intelligently calculating hundreds to thousands of systems sizes and combinations. Alternatively, you can specify the sizes to be considered using the “Size your own” option. 

The HOMER Optimizer is calculation-intensive, and if you select this option, you should expect to wait for as long as a few hours for your results. Using size-your-own will not automatically identify the most economic system size, but you will get results faster by limiting the number of sizes that HOMER Grid will consider and analyze. Size-your-own also lets you simulate systems with particular sizes. We recommend using the Optimizer initially in order to fully understand the potential, and then size-your-own to more fully explore potential around systems of most interest.
9. Consider adding storage to your system
To consider storage as part of your system, navigate to Storage, located under Component in the tree menu. Add storage through the Quick Pick drop-down menu (shown here as ‘Generic 1kWh Li-Ion [ASM]’). If you would like more storage options, click the Complete Catalog button. 

Once you have selected the storage you would like to consider, click ‘Ok’ to add the storage to your model.

10. Address any Required Changes
Use the suggestions in the required changes menu at the bottom of the screen to understand what is necessary before you can calculate.

The changes in red are required. The changes in yellow are recommended. The changes in green provide helpful tips.

The required changes shown tell us that we must add a system converter and a solar resource.
When you click “Add a system converter,” a default system converter will be added to your model automatically. You can also add a particular converter component in the tree menu on the left.

When you click “Add solar resource,” the solar GHI resource window will open. You can also navigate to Solar GHI under Resource in the tree menu on the left. Click the Download From Internet… button to quickly download solar data into your model. Choose between the NREL or NASA solar databases for downloaded data and click Ok. You may also choose upload your own solar resource data if you have it available.

11. Last check before you calculate
After ensuring that your model is correct and there are no required changes, click the Results button at the top of the window. HOMER Grid will automatically begin calculating the results for your model. Once it completes the calculations, you will see the results. (Note: If you are using the HOMER Optimizer, it may take as long as a few hours to get results.)

12. Evaluate your results at a high level
The results open at the Optimization Results table, which shows the categorized system architecture combinations and ranks the results from lowest Net Present Cost (NPC) to highest NPC. The cost of energy (COE) and other high-level economic metrics can be seen in the table as well. 

13. Dive into the simulation details
To view the more detailed Simulation Results for a particular system, double-click on any of the rows in the Optimization Results table, or click the Simulation Results icon in the far-left column.

Click through the tabs to get information about cost summary, cash flow, electrical performance, and emissions of the system. There are also tabs for each power system component; clicking on any of these gives you detailed information on how that component is operating in this particular system.

Click Time Series Plot in the bottom of the window to see the dispatch decisions made over the course of a year for this system. 

You can also click the Report button to get a summary report of your system.

14. Next steps
This guide walked you through optimizing the design of a basic solar+storage system to reduce utility bills. HOMER Grid includes many more features, including:
  • sensitivity analysis to understand how different inputs will affect your design
  • combined heat and power (a.k.a. cogeneration)
  • detailed storage and battery modeling
  • customized reporting for sharing your results
  • and much more

If you would like help using HOMER Grid for your project, we offer training and premium support to help you get your results even faster. You can read more about those programs on our website at https://www.homerenergy.com/support/.

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