# Voltcast

> Voltcast is the accuracy-accountable European electricity price API: day-ahead spot prices for 47 European bidding zones — EU-27 markets plus Norway, Switzerland, the Western Balkans (incl. Albania, Kosovo, Bosnia grid data) and Ukraine (UAH prices) — at native 15-minute resolution with history to 2015 (GB via Elexon: MID wholesale reference prices in GBP, imbalance and grid data), plus world markets through the same endpoints in native currency: the US (ERCOT Texas load zones, NYISO zones A-K, MISO trading hubs, CAISO hubs — with live volt forecasts where they beat the baseline), Canada (Ontario, Alberta) and Australia/New Zealand, intraday auction prices for 9 zones (IDA1/2/3: ES + PT via OMIE, all 7 Italian zones via GME — auctions, not exchange-proprietary continuous trading) with an ML spread forecast (volt-spread-1, scored daily against a disclosed climatology baseline), EXAA auction prices (AT + DE-LU), cross-border physical flows, P10/P50/P90 price forecasts whose accuracy is published daily against a naive-persistence baseline, wind/solar generation forecasts (our own volt-res-1 model scored head-to-head against the TSO's official forecast in every response), zone-centroid weather with ensemble bands, station-exact probabilistic daily Tmax/Tmin temperature forecasts (Volt Temp: full distributions and 1°C bucket probabilities on the named airport gauges markets and CME weather contracts settle on, e.g. Paris-Le Bourget, verified daily against METAR observations), CME-city degree-day settle-index trackers (HDD/CAT for Amsterdam, Essen, London, Paris), population-weighted zone temperature (the RTE/Enedis-style demand metric), imbalance and FCR/aFRR/mFRR reserve prices, load, generation mix, carbon intensity, outage events, optimization tools (cheapest window, charge schedule, battery arbitrage), PPA capture analytics, point-in-time ML feature matrices, a bitemporal as-of API, Monte Carlo price scenarios, and webhooks that fire within seconds of the 13:00 CET day-ahead auction and each IDA session. If the forecast fails to beat the free baseline in a zone for a month, that zone is credited automatically — a contractual commitment, not marketing.

Key facts: REST JSON API at https://voltcast.com/api/v1 (Bearer API-key auth; new access starts with Home at https://voltcast.com/register?plan=home). Home+ can also request Excel-compatible CSV from the bounded prices, forecasts and negative-price risk endpoints with `format=csv`; Pro+ full-history bulk export remains separate. Native MCP server for AI agents at https://voltcast.com/api/mcp (streamable HTTP; tools: list_zones, get_prices, get_forecast, get_carbon, get_renewables, cheapest_window; list_zones needs no key). Python SDK: `pip install voltcast`. TypeScript SDK: `npm install @voltcast/sdk`. Data sources: ENTSO-E Transparency Platform, SMARD (CC BY 4.0), Elexon BMRS, netztransparenz.de, regelleistung.net, Open-Meteo — always attributed. Current plans: Home €9/mo (1 zone, 7d P50, Excel-ready API CSV, 14-day negative-price risk, bill-context charging windows, battery simulator, Home Assistant action entities, unlimited webhooks and SSE) · Starter €49/mo (all zones and 1y history) · Pro €199/mo (adds P10–P90, wind/solar + weather forecasts, population-weighted zone temperature, imbalance/ancillary/outages and full-history bulk export) · Scale €499/mo (adds balancing data, analytics, as-of, scenarios and station-exact temperature). Existing Free accounts remain grandfathered with their original one-zone limits.

## Docs

- [API reference](https://voltcast.com/docs): every endpoint with examples — prices, forecasts, renewables & weather, imbalance, ancillary, load, generation, carbon, outages, optimization, battery simulator, PPA analytics, retailer simulation, ML features, as-of, scenarios, webhooks, SSE stream, MCP, integrations
- [OpenAPI specification](https://voltcast.com/openapi.json): machine-readable API schema
- [Live forecast accuracy](https://voltcast.com/accuracy): daily MAE/pinball per zone vs baseline — the accountability page
- [Ingestion status](https://voltcast.com/status): source health, measured uptime, webhook latency

## API endpoints (base https://voltcast.com/api/v1, Bearer key unless marked public)

- Public, no key: GET /zones · GET /accuracy · GET /status/ingestion · GET /public/negative-prices · GET /briefing/{zone} · GET /widget/{zone} · GET /indices/flex/{zone} · GET /bench/leaderboard · GET /telemetry/flex/stats · GET /demo/prices · GET /demo/savings · GET /temperature/stations · GET /demo/temperature
- Prices & auctions: GET /prices/{zone}?format=json|csv · GET /intraday/{zone} · GET /intraday/{zone}/spread · GET /exaa/{zone} · GET /history/export
- Forecasts & risk: GET /forecasts/{zone}?format=json|csv · GET /renewables/{zone} · GET /weather/{zone} · GET /risk/negative/{zone}?format=json|csv · GET /imbalance/{zone}/forecast
- Temperature: GET /temperature/{station} (probabilistic Tmax/Tmin, 1°C buckets) · GET /degree-days/{city} (CME HDD/CAT trackers + settle projections) · GET /temperature/zone/{zone} (population-weighted demand metric) · GET /features/temperature/{station} (specialized training matrix)
- Grid & balancing: GET /load/{zone} · GET /generation/{zone} · GET /carbon/{zone} · GET /flows/{zone} · GET /imbalance/{zone} · GET /ancillary/{zone} · GET /outages/{zone}
- Optimization & analytics: POST /optimize/cheapest-window (`cost` default; carbon/balanced are experimental historical-profile heuristics, not forecasts/emissions claims; optional variable tariff) · POST /optimize/schedule (optional variable tariff) · POST /optimize/battery · GET /capture/{zone} · POST /ppa/value · POST /simulate/retailer · POST /scenarios
- ML & audit: GET /features/{zone} · GET /features/{zone}/export · GET /features/temperature/{station} · GET /asof/{zone}
- Events: GET /stream (SSE) · GET/POST/DELETE /webhooks (events: auction_published, ida_published, unavailability_published, price_below, price_above, negative_prices) · POST /bench/submissions
- Agents: POST https://voltcast.com/api/mcp (MCP streamable HTTP)

## Data & analysis

- [Live power map (Terminal)](https://voltcast.com/terminal): interactive map of all bidding zones with 9 data layers (price, P50 forecast preview, carbon intensity, green score, renewables, animated wind field, population-weighted temperature with settlement-station pins, negative-price risk, IDA spreads), cross-border flow overlay, hour scrubbing, time travel over the 2015+ archive, shareable view links, and a 3D globe mode (toggle bottom-right or press G, `?proj=globe`) rendering the whole earth with idle auto-rotation — free, no login. The carbon and renewables layers extend worldwide with Ember monthly per-country estimates (clearly labeled ESTIMATED, `/api/v1/public/terminal/global`), and the "Carbon story" (`?story=carbon`) animates the world's power-sector carbon intensity month by month since 2015
- [European temperature outlook](https://voltcast.com/temperature): station-exact Tmax/Tmin distributions on the named settlement gauges (resolution-station registry with integrity monitoring), CME-city degree-day trackers, record watch — free teaser, no login. Informational/analytical use only, never wagering advice
- [Voltcast Research](https://voltcast.com/research): data-backed publications where every figure is computed live from the production database — monthly European power roundups, event post-mortems (including our own forecast misses), per-zone explainers (46 zones, German twins for DE/AT), methodology papers, global carbon annuals (one per year since 2015, `/research/global-carbon-{year}`), and country energy profiles for every Ember-tracked country worldwide (`/research/countries/{iso}`). Free to cite with attribution
- [Home Energy Research Working Papers](https://voltcast.com/research/home-energy): 100 preregistered, evidence-backed studies of 15-minute prices, negative-price events, EV charging, batteries, heat pumps, forecast uncertainty, tariff safeguards and reliable automation. Every paper has HTML, `text/markdown`, a frozen evidence JSON and an original figure; null and insufficient outcomes remain published
- [Renewable fleet map methodology](https://voltcast.com/research/renewable-fleet-map): operating wind fleets in Germany, Great Britain, Norway and the Netherlands plus Germany’s geolocated operating solar subset; national-register coverage, generic 3/12/25 m/s wind curve, map encoding, source licences and omissions disclosed. Displayed output is modelled from Open-Meteo weather, not metered generation
- [DE-LU actual-weather year wheel](https://voltcast.com/research/germany-weather-year-wheel): interactive month × local-hour atlas of DWD gauge rain and ERA5 cloud, 100 m wind, temperature and solar radiation for a frozen 2025-10-01→2026-08-02 40-point German field. Public JSON: `/research-data/de-lu-actual-weather-year-wheel-v1.json`; realized weather only, with no PnL, hit rate, fills or strategy data
- World markets (G3): day-ahead/spot prices extend well beyond Europe — the US (ERCOT Texas load zones, NYISO zones A-K incl. New York City, MISO trading hubs, CAISO trading hubs — USD), Canada (Ontario IESO, Alberta AESO pool price — CAD), Australia's NEM (5-minute dispatch, AUD) and New Zealand (NZD), all served through the same `/api/v1/prices/{zone}` endpoint with zone-native currency; see `/api/v1/zones` for the full registry with region, currency and per-market coverage notes
- [Daily guides](https://voltcast.com/guides): one worked example per day computed from that week's real auction data — EV charging windows and yearly savings, home-battery arbitrage, solar capture rates, negative-price watches with forward risk, forecasting baselines, station week-in-reviews — from hobbyist to quant, numbers frozen at publication
- [Voltcast Desk demo](https://voltcast.com/desk/demo): the trading workspace on yesterday's data — zone board with model-vs-market gaps, event tape (auctions/outages/negative clears with measured arrival times), auction clock, station desk with live METAR trajectories, run drift, percentile context vs 2015+, degree-day settle desk, BE 1-minute imbalance monitor. Decision support only, no order execution
- [Zone index](https://voltcast.com/zones): all 47 bidding zones with live price summaries and daily briefings
- [Monthly market reports](https://voltcast.com/reports): auto-generated per-zone statistics (averages, negative-price hours, spreads, volatility)
- [Voltcast Forecast Bench](https://voltcast.com/bench): open forward-blind day-ahead price forecasting leaderboard — any key can compete, scoring code published
- [Negative-price tracker](https://voltcast.com/negative-prices): live counters, records and monthly history of negative electricity prices per zone — free, no login, citable with attribution, per-zone monthly CSV downloads; Home+ adds interval API CSV for Excel
- [Voltcast Flex Index](https://voltcast.com/indices): daily per-zone value of load-shifting, versioned methodology
- [Renewables forecasts vs the TSO](https://voltcast.com/accuracy): our volt-res-1 wind/solar model scored against the TSO's A69 forecast on identical slots — wins and losses both published
- [Daily briefing API](https://voltcast.com/api/v1/briefing/DE-LU): public "why is tomorrow priced this way" explanations per zone, free to quote with attribution

## Integration

- [Use Voltcast inside ChatGPT & Claude](https://voltcast.com/ai): connector setup for claude.ai (custom connector + authorization header), ChatGPT (Apps & Connectors / GPT Actions via https://voltcast.com/openapi-gpt.json), Cursor/VS Code mcp.json, and `npx voltcast-mcp` for local stdio
- [llms-full.txt](https://voltcast.com/llms-full.txt): the full documentation in one file, sized for context windows
- [MCP server config](https://voltcast.com/docs#mcp): connect Claude, Cursor or custom agents in one config block
- [Embeddable price widget](https://voltcast.com/docs#widget): one script tag, free
- [Home Assistant action entities, evcc, Grafana, n8n, Google Sheets](https://voltcast.com/docs#integrations)

## Legal

- [Data licensing](https://voltcast.com/legal/data-licensing): what is redistributed and under which terms
- [Terms](https://voltcast.com/legal/terms): including the automatic beat-the-baseline credit (§4)

## Optional

- [For temperature-market analysts](https://voltcast.com/prediction-markets): why the settlement station is the edge — station-exact distributions, bucket probabilities, uncertainty signals. Analytics only, never wagering advice
- [Comparison: ENTSO-E API alternative](https://voltcast.com/entsoe-api-alternative)
- [Comparison: electricity price APIs](https://voltcast.com/electricity-price-api)
- [Comparison: aWATTar alternative](https://voltcast.com/awattar-api-alternative)
- [Comparison: Electricity Maps alternative](https://voltcast.com/electricity-maps-alternative): prices + forecasts + carbon in one API vs a carbon-only feed
- [German: Strompreise heute](https://voltcast.com/de/strompreise), [morgen](https://voltcast.com/de/strompreise-morgen), [negative Strompreise](https://voltcast.com/de/negative-strompreise), [Prognose](https://voltcast.com/de/strompreis-prognose), [Capture-Preise](https://voltcast.com/de/capture-preise)
- [Pricing](https://voltcast.com/#pricing)