---
title: "Calculate simultaneity factor (G-Factor) for a ZNP project"
method: GET
path: "/api/znp/projects/:projectId/g-factor"
tags: ["Zielnetzplanung (ZNP)"]
---

# Calculate simultaneity factor (G-Factor) for a ZNP project

`GET /api/znp/projects/:projectId/g-factor`

## Request

- Base URL: `https://api.cernion.de`
- URL: `https://api.cernion.de/api/znp/projects/:projectId/g-factor`
- Auth: none declared

Traverses all CONTRIBUTES_LOAD edges with `layer ≤ targetLayer` inbound to the specified substation node, sums asset capacities, and applies the simultaneity factor (Gleichzeitigkeitsfaktor) from VDE-AR-N 4100.

**Immutable Stacking:** The graph is never mutated — layer filtering happens at query time (Short-Circuiting). This means you can call calculateGFactor with `targetLayer=0` even after addLayer1 has been called, and the result will only reflect Layer 0 assets.

## Path parameters

- `projectId` string, required

## Query parameters

- `target_layer` integer
- `substationId` string
- `token` string

## Response `200`

G-Factor calculation result

- object
  - `projectId` string
  - `substationId` string
  - `targetLayer` integer
  - `assetCount` integer
  - `totalCapacityKW` number
  - `simultaneityFactor` number
  - `adjustedCapacityKW` number

---

[API](https://skmtc.dev/cernion/apis/cernion-energy-tools-api.md) · [All operations](https://skmtc.dev/cernion/apis/cernion-energy-tools-api/llms.txt) · [OpenAPI document](https://skmtc.dev/cernion/apis/cernion-energy-tools-api/revisions/cdb94473b538?raw)