How do I provide estimated energy production for a system?

Enlighten allows you to provide estimated energy production for comparison with actual system performance.

You have two options for providing estimated production:

1. Provide production estimates for each array in the system. With this option, you can have Enlighten retrieve estimates from the National Renewable Energy Laboratory (NREL) PVWatts™ calculator.
2. Provide one estimate for the full system using your own model for estimated production.

Entering Array-Level Production Estimates

To input estimated production at the array-level:

1. Go to Settings () and scroll down to Production Estimate & Threshold. Select Array-level production estimates.

   

2. Enter an Annual Degradation Factor, or use the default value of 0.5%.
3. Save Changes.
4. Click array details to expand the Estimated Production window.
5. To estimate energy production using the NREL PVWatts model, select Use PVWatts.

   

   • Enter the DC Array Size in kW. If you entered the PV module manufacturer and model, Enlighten automatically calculates DC Array Size by multiplying the number of modules in the array with the PV module nameplate rating.
   • Select Standard or Efficient for Module Type. Module type accounts for efficiency, cell material, and temperature coefficient. You can find these properties on the PV module data sheet.
     

     Module Type	Efficiency	Cover Type	Temperature Coefficient
     Standard (poly- or mono-crystalline silicon)	approximately 15%	Glass	-0.47%/◦C
     Premium (monocrystalline silicon)	approximately 19%	Anti-reflective	-0.35%/◦C

   • If you don’t know the PV module type in this system, select Standard.
   • Enter the estimate for System Losses. System losses account for other performance factors that are not explicitly calculated in PVWatts. If you don’t have a way to calculate losses for a system, you can use 14%, which is the NREL default value.
6. If you are using your own model, select Use values from another model and provide the monthly solar radiation and projected energy production.
7. Click Save Changes. If you selected PVWatts, Enlighten retrieves an estimate for the array.

Entering System-Level Production Estimates

To input estimated production at the system-level:

1. On the System Activation form or on system Settings (), scroll down to Production Estimate & Threshold and select System-level production estimates to display the estimate form.

   

2. Enter estimated energy production in kWh for each month of the year.
3. Enter an Annual Degradation Factor, or use the default value of 0.5%.
4. Click Save Changes.

Find out how Enlighten uses estimated production.