What system size should I choose? (Help Me Size)

It can be difficult to know what is the right system size for your customer. That's because there is a trade-off between system size and the export % / ROI  –  more power is export to the grid as you increase system size, meaning you get diminishing returns from increasing system size.

To speed up the process of assessing multiple options for system size, PVsell incorporates "Help Me Size" functionality which can quickly present the results for a range of system sizes. You'll find the "Help Me Size" button alongside the array and inverter capacity inputs on the "System Tab".

Here are the details on how to open the "Help Me Size" feature window

1. Open the project you wish to size the system for

How can I view my list of projects?

2. Open the project's "System" tab

3. Click on the "Help Me Size" button next to the System Size input fields

You'll then be presented with two options: "Chart" and "Compare"

1. Chart progressively presents a selection of system size options
2. Compare lets you enter system sizes of your choice to compare

Option 1: Chart

When the "Help Me Size" window loads, it will progressively reveal the export % and ROI (guide) for a range of system sizes.

The system sizes (Array, kW) will automatically be chosen to provide a growing contribution of solar energy to the site's energy consumption. These values will be plotted on the chart on the left, and listed in the table on the right.

PVsell estimates the system price for each system, using an algorithm that will increase in sophistication over the course of time. Based on these system prices and the calculated 1st year savings, the ROI is calculated. Because the system price calculated by PVsell may not be the final price you choose to sell your system at, the prices and ROI should be treated as a guide only.

• To incorporate one of the options into your project, click on that system in the table, then click "Use Selected".
  Note this will overwrite the values currently stored in the "System" tab.
• Or, to keep the values currently stored in the "System" tab, click "Keep Original".

Option 2: Compare

This tab provides more control over the options to be compared.

Enter information about the system size and price (of your choice), then click "Add".

• To incorporate one of the options into your project, click on that system in the table, then click "Use Selected".
  Note this will overwrite the values currently stored in the "System" tab.
• Or, to keep the values currently stored in the "System" tab, click "Keep Original".

You can also load in options for comparison from your library

1. Click "Select Library Item"
2. Find the system of interest from your library, either by searching by name/description, or by scrolling through the pages of the library
3. Click the '+' sign in the "Add to Comparison" column beside the library item of interest

Learn more: What ways can I input my system price when entering a project?