Open source billing software for Swiss ZEV and vZEV energy communities.
A ZEV is one grid connection shared by several households, which means somebody has to work out who owed what for the solar. OpenZEV does that end to end: import the meter load curves, split each 15-minute interval between participants, price it against your tariffs, and produce a PDF invoice with a QR-bill payment slip.
I wrote it to bill my own ZEV, and put it out in case it is useful for yours. Self-hosted, AGPL-3.0.
- Built for personal use and self-hosting tinkerers who enjoy running their own stack.
- Shipped as-is, with no warranty (yes, even when it looks great in the dashboard).
- Check your data and billing outputs before they reach a participant. I can't take responsibility for incorrect imports, calculations, invoices, or invoicing workflows.
- Built with generous AI assistance, right down to the specs, ADRs, and user docs. Some choices may therefore look a little unconventional, or fall short of what a more experienced team would do today. That is not accidental: the project is optimized for learning, experimentation, and running my own ZEV, not for enterprise-grade process perfection.
- Communities and roles: access per ZEV for managers, viewers and participants, with dated participant-to-meter assignments for tenant changes
- Metering import: CSV, Excel and SDAT-CH, with a preview before anything is written and a data-quality view for gaps and duplicates
- Billing engine: allocation per 15-minute interval, versioned tariffs with high/low bands and seasons, dynamic prices, and tariff import from your grid operator
- Invoices: draft → approved → sent → paid, as PDF/A-3b with a Swiss QR-bill, plus annual statements and participation contracts
- Email delivery: asynchronous, with per-invoice history and retry
- Feasibility calculator: savings, payback and ROI for a community you have not founded yet
- Also: German, French, Italian and English UI, API keys, audit log, whole-ZEV export/import, backups, and an MCP server for AI assistants
See the user guide for the details, and the roadmap for what is shipped and what is next.
Try it with demo data (needs Docker or Podman with Compose):
git clone https://github.com/splattner/openzev.git
cd openzev
scripts/start-demo-environment.shThen open http://localhost:8080 and sign in as admin@openzev.local / admin1234.
The demo runs with DEBUG=True and well-known passwords, so never use it for real data.
To run OpenZEV for your own community, every release ships a ready-made
docker-compose.yml for the published images, and there is a Helm chart in
charts/openzev for Kubernetes. The
Getting Started guide covers both, plus
HTTPS, email, the first admin account, backups and updates.
- User guide (sources in
docs/user-guide/): setup, imports, tariffs, billing and administration - Roadmap and release notes
- API reference: Swagger UI at
/api/docs/and ReDoc at/api/redoc/on a running instance - Specs and architecture decisions
- Backend: Django, Django REST Framework, SimpleJWT
- Frontend: React, TypeScript, Vite, TanStack Query, i18next
- Async jobs: Celery worker and Beat with a Valkey broker (Redis-compatible)
- Database: PostgreSQL for production billing; SQLite for local development/tests. MariaDB is not supported by the metering correction and identity-lock workflows.
- Deployment: Docker Compose, or the Helm chart on Kubernetes. Images are published to GHCR, signed, with an SBOM.
Issues and pull requests are welcome. CONTRIBUTING.md covers the development setup, the checks CI runs, and the spec-driven process for larger changes.
Please report vulnerabilities privately, as described in SECURITY.md.