WattTime's core offering is our data on the marginal emissions rate of different power grids, in real time. We enable IoT companies to automatically reduce emissions from their products by shifting usage to the times that are less polluting. Our partners work with a wide range of flexible load types, from air conditioners and building chillers, to electric vehicles and battery storage.
This is a little bit similar to the concept of "demand response," but has greater environmental benefits. So, we call it "Environmental Demand Response" or EDR.
However, we've found that many others are interested in WattTime data too. We've also helped researchers analyze the power grid, educators teach about clean energy, and companies do their carbon accounting.
Most of the data is time-series oriented, kind of like a weather API—what's happening on the regional grid at a particular moment? In addition to metadata about data provenance, three kinds of data types are provided for each time series data point:
Geographically, the data are organized the same way the grid is: into "balancing authorities" that manage supply and demand for a given service area. The bigger balancing authorities, called Independent Services Operators and Regional Transmission Organizations (ISOs/RTOs), together cover about 2/3 of US electricity consumers.
The WattTime API provides marginal carbon emissions data for all balancing authorities in the lower 48 states of the US, and generation mix and average carbon emissions data for these ISOs/RTOs:
Power generation data are pulled straight from the ISOs in real time, as frequently as they release it: every 5 minutes in ISONE, MISO, NYISO, PJM, and BPA; every 10 minutes in CAISO; and every hour in ERCOT.
We combine this with CO2 emissions factors from the Energy Information Administration to calculate the average carbon emissions. In a few cases we have to use approximations if a region combines two fuel types. For example, BPA's data focuses primarily on its substantial renewable energy resources and doesn't distinguish between different types of thermal power plants.
The marginal carbon emissions are calculated using WattTime's proprietary algorithm, which matches real-time data about what's happening on the power grid (from balancing authorities and other sources) to historical data about the marginal carbon emissions in similar grid conditions (from the EPA). Learn more about WattTime's research here.
Get started by checking out the interactive documentation, the tutorials, and the user group. It's a standard RESTful JSON API, so you can make HTTP requests to API endpoints using any of your favorite tools, from iOS to d3.js to curl.
The API is completely free and open to anyone at the Visitor and Open levels, although access is rate-limited if you don't use an API token. API tokens are free and easy to get: just register for a user account. Data availability terms are subject to change without notice, although of course we'll do our best to keep the user group informed about any upcoming changes.