One file. Every stakeholder. Any PV system.
DERpass is an open JSON standard that captures everything about a photovoltaic system — hardware, history, contracts, and grid connection — in a single portable file. Installers hand it over. Operators maintain it. Investors, insurers, and grid operators read exactly what they need.
Like a car's service book, a DER Passport captures the full life of a power-generating asset — from commissioning, through maintenance events and ownership changes, to eventual decommissioning. When the system is sold or handed over to a new operator, the passport moves with it.
DERpass defines a open JSON Schema for this record. Any tool that speaks JSON can read, write, or validate a DER Passport. There's no vendor lock-in, no proprietary API, no central registry required.
National profiles (currently DE, NL) layer jurisdiction-specific fields — MaStR numbers, VDE norms, EAN codes — on top of the common core, keeping the standard both generic and locally precise.
.derpassA 10 kWp residential system — from commissioning day to property sale.
The installer uses the AI prompt to generate a DER Passport from the commissioning report. Hardware specs, MaStR number, and feed-in tariff rate are captured in a single file. The homeowner receives one structured file — not a folder of PDFs.
Generate with AI →The O&M provider opens the same file, appends a maintenance event to the events array, and returns the updated passport. The content-hash chain records the revision — any silent alteration is detectable.
The buyer's insurer validates the file against the JSON Schema. Component ages, maintenance cadence, and insurance coverage are machine-readable. No questionnaire. No missing documentation. The assessment takes minutes, not weeks.
View the schema →Two sides of the same problem — the people who create the data, and the people who need to trust it.
Commissioning reports lived in PDF folders on a shared drive. Datasheets were scanned, photos stored on personal phones. Handing over to an O&M provider meant emailing a ZIP archive and hoping nothing was lost in translation.
Assessing a distributed PV portfolio meant requesting technical data from installers, yield reports from operators, and contracts from owners — all in incompatible formats. Data rooms contained PDFs that could not be queried. Bankability assessments stretched over weeks.
One .derpass file carries the complete asset record through ownership changes, grid operator handovers, and installer switches.
Built on JSON Schema draft 2020-12. Validate with any off-the-shelf library. No central authority, no registration required.
Covers components, metering, grid connection, compensation, insurance, contracts, remote access, and a full event log.
National profiles for DE and NL layer jurisdiction-specific fields. The additionalProperties model lets you add your own without breaking conformance.
Events and file revisions carry optional JWS signatures. A content-hash chain links each revision to the last, enabling tamper detection across handovers.
Drop any .derpass into the viewer to get a rendered, printable document — no software install required.
Eight chapters cover most real-world needs — all are optional beyond the four required fields.
DERpass removes the translation layer between the parties who install, operate, finance, and regulate distributed energy resources.
Commissioning reports lived in PDF folders on a shared drive. Datasheets were scanned, photos stored on personal phones. Handing over to an O&M provider meant emailing a ZIP archive and hoping nothing was lost in translation.
Each managed asset had its own spreadsheet — partially filled by the installer, partially by the operator. Maintenance history sat in a ticket system disconnected from asset data. Owner reports required pulling exports from three different tools.
Installers submitted grid connection requests on paper or proprietary online portals. DSO staff re-typed nameplate data into internal systems. Transcription errors caused delays, re-submissions, and weeks of back-and-forth before a system could be connected.
Ownership transfers required collecting scanned contracts, installer certificates, and grid approval letters from multiple parties. Establishing a clean chain of title for a PV asset could take weeks, with gaps in the record being the norm rather than the exception.
Assessing a distributed PV portfolio meant requesting technical data from installers, yield reports from operators, and contracts from owners — all in incompatible formats. Data rooms contained PDFs that could not be queried. Bankability assessments stretched over weeks.
Underwriting a PV asset required sending questionnaires to the owner, waiting for answers, and manually verifying them against whatever documentation could be found. Component age, maintenance frequency, and grid protection settings were rarely available in a consistent format.
Download the JSON Schema and use it to understand the structure. Any JSON Schema validator will tell you whether your file is valid.
core/v1.0/schema.jsonOnly four top-level fields are required: derpass_version, jurisdiction, meta, and commissioning. Add sections as you need them.
"derpass_version": "1.0"
"jurisdiction": { "primary": "DE" }
"meta": { … }
"commissioning": { … }
Drop your .derpass file into the viewer to see it rendered as a structured, printable document. No upload, no account — runs entirely in your browser.
Software tools, platforms, and services that produce, consume, or validate .derpass files.
Commissioning workflow tool that exports a valid DER Passport at job close — modules, inverter specs, and grid data captured in one step.
O&M management platform that ingests DER Passports at asset intake, appends maintenance events, and returns updated files to asset owners.
DSO connection portal that accepts DERpass grid connection chapters as structured import — no PDF form, no manual re-keying of nameplate data.
Investor due-diligence tool that aggregates technical specifications, yield history, and compensation terms from DER Passport files across entire portfolios.
Underwriting platform that validates DER Passport files to extract component age, maintenance cadence, and existing coverage — replacing owner questionnaires.
Cloud storage and indexing service for DER Passport files — search, version, and share structured asset records across organisations and ownership transitions.
.derpass files using off-the-shelf tooling..derpass file lives on your filesystem, your own server, or wherever you choose to store it. There is no central registry, no API to call home to, and no account to create. The Viewer on this site runs entirely in your browser — your file never leaves your device.additionalProperties throughout, so you can attach your own fields at any level without breaking conformance. We recommend prefixing custom fields with your organisation's namespace (e.g. x_acme_voltage_offset) to avoid collisions with future schema versions.DE) and the Netherlands (NL) add jurisdiction-specific fields: MaStR numbers, VDE norms, and EAN codes for Germany; SDE++ references and E17 EAN codes for the Netherlands. Additional profiles are under discussion."derpass_version": "1.0"), so older files remain valid and readable against the version they reference.