Heartland uses the formula for "appropriately sized" found in Kansas law and shown below.
When plugging in your annual kWh used, we look at your actual electric use over the past 12 months. If you’re new, we estimate based on the square footage of conditioned space (7.15 kWh per square foot per year).
For existing locations:

For new locations:

The result, rounded up, is the maximum system size we can approve for export.