Component Guide

Planning an Ensemble Technology System – North America

Self-Consumption Use Case

In Self Consumption scenarios, a homeowner’s PV system generation is stored in the Encharge storage system for

use later in the day when there is not sufficient power from Solar PV to supply the home loads. Homeowners benefit

by consuming the onsite-generated energy themselves instead of exporting it to the grid during the day and purchasing

power from the grid during evening and night times.

In customer self-consumption scenarios, size the Encharge storage capacity to accommodate the expected daily

energy export. This is roughly less than two-thirds of the average daily energy load of the home.

Economic Use Cases

There are many economic goals that the Encharge storage system supports. These include reducing the utility bill

by charging during low tariff periods and saving charge to ensure that loads can be served through the battery(ies)

during the peak tariff period. Power from PV can be exported to the grid especially during peak tariff periods.

The system also supports the special case of power export limiting, where the utility does not allow a homeowner to

export power from the PV system to the grid. Examples are the Hawaii self-supply and NEM+ programs where no

export is allowed, which is called zero export.

Optimizing energy storage capacity sizing for economic use cases is beyond the scope of this document. You can

use simulation tools like NREL SAM (System Advisor Model) or Energy Toolbase to assist with sizing in these use

cases.

Smart Profiles

The Encharge storage system supports 3 smart profiles for the batteries to implement the backup, self-consumption

and economic use cases described above.

These are:

1. Full Backup – 100% of the battery capacity is reserved for backup and the battery does not discharge while on-

grid.

2. Self-Consumption – The battery discharges until reserved capacity to ensure the home loads are served with PV

and storage as far as possible. Effectively the system tries to reduce import from the grid whenever possible.

Note the battery only discharges until the reserve charge limit while on-grid. The battery discharges below the

reserve charge limit only when the grid is down.

3. Savings – This profile is for the economic use case wherein the battery discharges when the rates are at the

peak and charges using PV prior to peak tariff periods. Note that the Encharge storage does not export to the

grid. During peak tariff period PV is exported to the grid and battery is discharged to serve loads. Note the

battery only discharges until the reserve charge limit while on-grid. The battery discharges below the reserve

charge limit only when the grid is down.

Description of these modes with screenshots of how homeowners can select the same is available in the Enphase

Storage system owner’s guide.

Note in all modes the battery will charge from the grid until the reserve charge limit to ensure that the desired amount

of battery charge for backup is guaranteed to be available.