PV-Flow: Open Smart EV Charging with AtomS3R, Tibber & OCPP

👉 Sign up for the Private Beta on pv-flow.de

What is this project about?

PV-Flow is an intelligent, edge-driven EV energy management system designed to make charging cheaper, faster, and greener. By processing real-time photovoltaic (PV) surplus generation alongside dynamic spot-market prices (such as Tibber), PV-Flow automatically regulates wallboxes via OCPP and Modbus TCP. It maximizes solar self-consumption and minimizes grid costs through direct local control without relying on opaque cloud platforms.

Why we made it?

Most EV owners face a frustrating trade-off: fixed-rate charging is expensive, while manually aligning charging with fluctuating solar output and hourly spot-market tariffs is tedious. Existing energy management solutions are often proprietary, expensive, or cloud-dependent. I built PV-Flow to deliver a high-frequency, responsive energy orchestrator running entirely on local hardware—giving users total control over their home energy automation while driving down charging costs.

How does it work?

PV-Flow functions as a fast, local control loop between your solar setup, market price feeds, and wallbox:

High-Frequency Edge Acquisition: An M5Stack AtomS3R microcontroller queries inverter and smart meter registers locally (via Modbus TCP or REST APIs) every sub-second to capture live PV generation.

Smart Data Processing: A smoothing algorithm calculates actual available surplus power and translates it into real-time amp limits (6 A - 16 A) to prevent erratic switching during rapid cloud movements.

Dynamic Price Integration: Combines local generation metrics with upcoming hourly tariff forecasts fetched via the Tibber API to trigger charging during low-cost spot market windows.

Direct Wallbox Control: Sends instantaneous charging profiles directly to wallboxes (like go-e or Easee) via local Modbus TCP, HTTP, or OCPP WebSocket connections for minimal latency (< 1 s).

Real-Time Analytics: Visualizes high-density time-series data locally using a light-weight UI powered by µPlot.

👉 Sign up for the Private Beta on pv-flow.de