What is retrofit interconnection?

Retrofit interconnection is a change to a solar, battery, or generator system that already has an interconnection agreement with the utility: a battery add-on, an inverter replacement, a PV expansion, a generator add-on, or a non-export or limited-export reconfiguration. It is a different filing shape than a brand new system, since the utility already has a file on that address.

Why does GridProjeX focus on retrofit first?

GridProjeX supports new installs, but its V1 wedge is residential retrofit interconnection, because that is the fastest growing and least served part of an installer's book: existing systems getting batteries, inverter swaps, expansions, and generator add-ons, none of which most permitting software treats as a distinct case.

Retrofit Interconnection Software | Battery, Inverter, PV Expansion

The V1 wedge

New installs work in GridProjeX. Retrofits are what it was built for first.

A new install has one interconnection application and one permit, filed once. A retrofit on a system that already has an interconnection agreement is a different shape of paperwork entirely: existing capacity, resulting capacity, whether the change trips a notice-only path or a full reapplication, and a utility that already has a file on this address. Most software treats a retrofit like a new install with extra fields. GridProjeX treats it as its own case from the start.

Battery add-onsAn existing PV system gaining storage: existing interconnection agreement, existing meter, the utility’s battery-specific interconnection or net metering amendment, and whether the addition changes the export rating.

Inverter replacementsA failed or upgraded inverter with a different nameplate rating than the one on file. Whether the utility treats a like-for-like swap as notice-only or requires a new application depends on the resulting AC rating against the existing agreement, not on the fact that something broke.

PV expansionsAdding panels to an existing array. Resulting DC and AC size against the utility’s screening thresholds, and whether the expansion is a new agreement or an amendment to the one on file.

Generator add-onsA backup generator added alongside existing solar and battery. Interconnection rules for a generator are frequently a separate program from the PV/storage rules at the same utility, with its own application and its own screens.

Non-export and limited-export changesA system reconfigured to export nothing, or to export under a cap, sometimes to avoid a full interconnection study. The utility’s non-export or limited-export program has its own equipment and metering requirements, tracked as its own requirement rather than assumed from the system size alone.

What carries over from the original systemEvery retrofit project in GridProjeX records the existing interconnection agreement, the existing meter, the previously approved capacity, and the proposed change against it — so a coordinator is never guessing what the utility already has on file for that address.

See it in the console on the installer page, or check PTO tracking for how a retrofit reaches permission to operate again.

The fastest growing part of your book, with a real workflow instead of a workaround.

New installs work in GridProjeX. Retrofits are what it was built for first.