"Services or tools available for free without requiring an API key" matching MCP servers:

Enables natural-language interaction with Ladybug Tools for building performance simulation, 3D modeling, and data visualization, allowing agents to perform complex environmental analysis tasks without CAD software.

MCP server providing deterministic, standards-traceable engineering calculations for combined-cycle power plant balance-of-plant design, such as fluid properties, pipe sizing, pump NPSH, and valve sizing, with every result including method, assumptions, and warnings.

Provides read-only access to Shelly Cloud energy data, including live power, lifetime energy, and historical consumption with cost, enabling AI agents to monitor electricity usage without device control.

87+ specialized tools for German and European energy data. Direct AI access to Marktstammdatenregister (MaStR), ENTSO-E, Redispatch 2.0, and Grid Operations for utilities and datacenters.

Enables exact residential electricity rates and itemized bills for Salt River Project, computed from filed tariffs with citations, via tools for listing plans, getting rates, and calculating bills.

Provides real-time electricity prices, cheapest hours, and contract comparison for 40+ countries, enabling AI agents to make energy-aware decisions.

Hourly electricity grid carbon intensity (gCO2eq/kWh) for 45 zones across Europe, the US and Great Britain, computed from ENTSO-E, EIA and NESO generation data. Four read-only tools; every value carries its interval timestamp and how stale it is. No API key, no account.

Live and historical electricity prices, demand, generation mix and carbon intensity for 25 grid zones (US, Europe, GB, Australia). Hosted endpoint plus local stdio bridge; free sample mode, free API key, or x402 pay-per-call.

Enables discovery and control of Philips Hue lighting devices via a local bridge using the CLIP v2 API, without any cloud dependency.

An MCP server that exposes the U.S. Energy Information Administration (EIA) Open Data API, enabling LLMs to browse and query energy data across 17 datasets with generic, composable tools.

Enables querying Danish energy data—electricity prices, carbon intensity, consumption, production, grid capacity, balancing markets, and gas—from Energinet's public Energi Data Service without an API key.

MCP server for fetching Danish electricity spot prices (DK1/DK2) using the free elprisenligenu.dk API, providing tools to get current price, cheapest hours, and price summaries.

The PGIQ Rating as agent tools: where to site or schedule a large electricity load across 67 global power markets. Wraps a read-only REST API returning reasoned, cited ratings across access, availability, cost, momentum, and carbon, plus live grid snapshots and cheapest-window scheduling.

Enables MCP clients to pull US ZIP-code-level electricity data — Scope 2 location- and market-based emission factors, Scope 1 fuel factors, hourly grid carbon intensity, plant-level emissions, retail rates, and utility tariffs — for carbon accounting, multi-site comparison, and finding the cleanest hours to run flexible loads. It requires no API key or signup and works as either a hosted remote endpoint or a local stdio process.

Connects Claude and other MCP clients to myGEKKO building controllers via the official Query API, enabling natural-language queries and control of smart-home devices. It is read-only by default, with write actions available only through explicit opt-in and safety policies.

Enables controlling ecobee thermostats from ChatGPT by connecting a user's ecobee account through normal browser sign-in, without an ecobee developer API key. Supports listing thermostats, reading status, setting temperature or HVAC mode, and resuming schedules.

Enables controlling Zaptec EV chargers through natural language, including checking charging status, viewing charge history with cost, pausing and resuming sessions, and setting available current.

MCP server for Kardashev Labs US grid data, giving agents live LMP, carbon intensity, load, curtailment, interconnection queues, ERCOT large loads, and the public RT-DA spread forecast track record. Requires no API key.

A Model Context Protocol server providing free financial market data across 13 categories with 83 no-key tools, enabling access to stocks, indices, options, forex, crypto, energy, prediction markets, and more.

Enables AI assistants to search and analyze Turkish electricity and energy market regulation by scanning the Resmî Gazete and EPDK, EPİAŞ, ETKB and TEİAŞ announcements, extracting amended articles and effective dates, and ranking changes by market importance with reasoning. It also provides source health status and rule-based effective-date extraction from any text, without requiring an API key.

Enables querying German distribution grid operator data from vnbdigital.de and BDEW register, including lookup by ID, postcode, coordinates, and free-text search.

Enables turning an address or lat/lng into a transparent solar proposal by geocoding it, pulling Google Solar API building insights (panel layouts, roof segments, imagery quality), and pricing a few system sizes with your tariff, install cost, incentives, savings, payback, NPV and a verdict. Every input is labelled with its source, Google's own financial analyses are shown side by side, and no prices are invented.

Enables classifying electricity meter days as active, standby, off, or unsure from 96 fifteen-minute kWh readings plus a meter reference, with batch support for up to 31 days and model metadata. Runs fully offline as a frozen scikit-learn classifier, exposing single-day and batch classification plus model-info tools over STDIO or HTTP.

Enables querying NASA POWER historical solar, wind, building, and agroclimatology data via MCP, including point time series, climatologies, native-grid regions, and comparisons across multiple labeled locations, with staged SQL analysis for larger datasets. Runs over STDIO or Streamable HTTP and requires no NASA account or API key.

Browse and query the U.S. Energy Information Administration API v2 — electricity, petroleum, natural gas, coal, forecasts, and more via MCP. STDIO or Streamable HTTP.

This MCP server provides a single read-only tool to query official CPFL (electric utility) bill download data via a hosted, prepaid service without requiring platform credentials.

Gives Claude, Cursor, VS Code and other MCP clients safe, structured access to an OpenSolar organisation's projects, contacts, systems, files, commercial settings and Teams sharing via the documented OpenSolar API. Runs self-hosted with your own bearer token, offering curated tools for searching, summarising, comparing, updating and sharing solar project data.

Exposes five deterministic tools over stdio so LLM agents can evaluate all seven kill methods, plan complete well kills and CWI stripping/snubbing operations, and create or step live simulator sessions without hallucinating safety-critical pressure math. Returns kill mud weight, MAASP, stage-by-stage procedures, rig gauges, kill sheets, and graded debriefs.

An MCP server that wraps the U.S. Energy Information Administration's Open Data API, enabling assistants to fetch live energy data via natural language. It provides tools for querying series, browsing data routes, filtering facets, and running custom queries.

Provides real-time grid carbon intensity, power generation breakdown, and carbon-intensity forecasts for any zone or lat/lon location.