Component Guide

Planning an Ensemble Technology System – North America

Use Cases and Sizing

Load Analysis

The first step in correctly sizing a system is a proper load analysis. If an Envoy with correctly configured consumption

CTs is already installed at a site, you can use data from Enlighten to properly size the system. A site survey, electric

bills, and third-party consumption meters can also provide useful load data for system sizing. Also, review the Enphase

Ensemble Project Survey document and System Estimator at estimator.enphaseenergy.com.

Backup Use Case

A backup system provides power to loads when the grid is down.

It is important to differentiate the terms power and energy. Power is a measure of the instantaneous electricity used

and is expressed in units of watts (W) or kilowatts (kW). Energy is the accumulated or integrated power used over time

and is expressed in units of watt-hours (Wh) or kilowatt-hours (kWh). When running in the backup operation, any power

capacity shortages or energy capacity shortages will result in a loss of power to loads and should be avoided. Therefore,

it is important to properly size the system for both power and energy capacities in each installation.

Sufficiently size the total Encharge storage system power rating to power loads and charge from PV power generation.

You can increase the power rating by adding additional Encharge storage units, which also provide additional energy,

improving the customer user experience.

• Power (kW) capacity from Encharge storage system must exceed the maximum single load. Total IQ 6 or IQ

7 series microinverters AC power rating connected to the microgrid may not exceed 150% of the total

Encharge continuous power rating (Table 1).

o 2017 NEC 690.10 -> 710.15 (A) Supply Output. Power supply to premises wiring systems shall be

permitted to have less capacity than the calculated load. The capacity of the stand-alone supply shall

be equal to or greater than the load posed by the largest single utilization equipment connected to

the system. Calculated general lighting loads shall not be considered as a single load.

• Energy storage (kWh) capacity should be sized to supply to the estimated backup loads for a user-defined

period.

Sizing Encharge Storage System for Whole-home (Main Panel) Backup

For whole-home backup, when an Enpower smart switch is installed on the line-side of the main load panel, at

minimum, the greater of a) two Encharge 10 units or b) number of Encharge 3 units to meet the IQ Microinverter PV

System to Encharge Pairing (see below), is recommended.

Sizing Encharge Storage System for Partial Home (Subpanel) Backup

For partial home backup, when an Enpower smart switch is installed on the load side of the main load panel follow

these steps to size an Encharge storage system:

1. Identify the largest maximum single load power rating (kW) that you want to backup, and select the absolute

minimum number of Encharge units required to meet the 2017 NEC 690.10->710.15(A) requirements.

2. Calculate the total PV system maximum continuous output power of all IQ 6 / IQ 7 series microinverters in the

system. Then select the minimum number of Encharge storage units required so that the total PV system

output AC power is not greater than 150% of the total Encharge storage system power capacity.

3. Based on the estimated backup loads for the user-defined period, calculate the required Encharge energy

storage (kWh) capacity and the minimum number of Encharge required.

4. Based on a site’s load analysis of both power (kW) and energy capacity (kWh) needed, determine the total

number of Encharge units required for the storage system.

a. The minimum number of Encharge 3 units required is the largest of the calculated values in steps 1 and

b. The desired number of Encharge storage system units is the value calculated in step 3.

c. The maximum allowed number of Encharge 3 units that can be connected to a single Enpower smart

switch is 12 (four Encharge 10).