Introduction

WattTime technology—based on real-time grid data, cutting-edge algorithms, and machine learning—provides first-of-its-kind insight into your local electricity grid’s marginal emissions rate.

The WattTime API provides access to real-time, forecast, and historical marginal emissions data for electric grids around the world. For a deeper understanding of these Marginal Operating Emissions Rates (MOERs) please see What is AER and How AER works.

You can access the API by sending standard HTTP requests to the endpoints listed below.

The /data, /historical, and /forecast endpoints are only available to subscribers. ANALYST and PRO data plans can be found here.

For (Python3) example code that can be used to register, log in, and query data, please see our example code.

Restrictions

There are strict limits on the number of connections and rates at which you may query the API. From any single IP address you may make a maximum of 10 connections, and may have up to 100 outstanding queries that will be rate limited to 10 requests per second. If there are more than 100 requests outstanding, or more than 10 connections, those requests may be dropped and an HTTP 429 error code returned.

Best Practices for API Usage

If using this API to control many smart devices in different locations, we suggest the following protocol. For each device location, query /ba-from-loc to determine the device's 'ba'. Then, query /index with the resulting 'ba's to receive MOER data.

Because region boundaries are occasionally updated, it is important to re-query /ba-from-loc at least once a month to ensure devices are receiving the correct signal.

Authentication

To start using the API, first register for an account by using the /register endpoint. Then use the /login endpoint to obtain an access token. You can then use your token to access the remainder of our endpoints. WattTime expects a token to be included in all API requests to the server. Your access token will expire after 30 minutes and you'll need to sign in again to obtain a fresh one.

Create New User Account

To register, use this code:

import requests
register_url = 'https://api2.watttime.org/v2/register'
params = {'username': 'USERNAME',
         'password': 'my_special_password',
         'email': 'some_email@gmail.com',
         'org': 'some org name'}
rsp = requests.post(register_url, json=params)
print(rsp.text)

curl -H "Content-type: application/json" --data-binary '{"username":"freddo", "password":"the_frog", "email":"freddo@frog.org", "org":"freds world"}' https://api2.watttime.org/v2/register

The above command returns JSON structured like this:

{
  "user": "freddo",
  "ok": "User created"
}

/register

Provide basic information to self register for an account.

HTTP Request

POST https://api2.watttime.org/v2/register

URL Query Parameters

Obtain Access Token

To register, use this code:

import requests
from requests.auth import HTTPBasicAuth
login_url = 'https://api2.watttime.org/v2/login'
rsp = requests.get(login_url, auth=HTTPBasicAuth('USERNAME', 'PASSWORD'))
print(rsp.json())

curl --basic -u USERNAME:PASSWORD https://api2.watttime.org/v2/login

The above command returns your personal token, in JSON structure like this:

{
  "token": "abcdef0123456789fedcabc"
}

/login

Use HTTP basic auth to exchange username and password for an access token. Tokens are used in all subsequent data calls.

HTTP Request

GET https://api2.watttime.org/v2/login

URL Query Parameters

Response

Password Reset

To reset your password, use this code:

import requests
password_url = 'https://api2.watttime.org/v2/password/?username=USERNAME'
rsp = requests.get(password_url)
print(rsp.json())

curl "https://api2.watttime.org/v2/password/?username=USERNAME"

Sample Response:

{
  "ok": "Please check your email for the password reset link"
}

/password

Provide your username to request an email be sent to you with password reset instructions.

HTTP Request

GET https://api2.watttime.org/v2/password

URL Query Parameters

Response

Grid Emissions Information

Determine Grid Region

Make sure to add in your registered USERNAME and PASSWORD to this code. You should not add in your token here. The code automatically generates a new token each time you run it.

import requests
from requests.auth import HTTPBasicAuth

login_url = 'https://api2.watttime.org/v2/login'
token = requests.get(login_url, auth=HTTPBasicAuth('USERNAME', 'PASSWORD')).json()['token']

region_url = 'https://api2.watttime.org/v2/ba-from-loc'
headers = {'Authorization': 'Bearer {}'.format(token)}
params = {'latitude': '42.372', 'longitude': '-72.519'}
rsp=requests.get(region_url, headers=headers, params=params)
print(rsp.text)

curl -H "Authorization: Bearer abcdef0123456789fedcabc" https://api2.watttime.org/v2/ba-from-loc?latitude=42.372&longitude=-72.519

Sample Response

{
"id":169,
"abbrev":"ISONE_WCMA",
"name":"ISONE Western/Central Massachusetts"
}

/ba-from-loc

This endpoint, provided a latitude and longitude parameter, returns the enclosing balancing authority details if known, or an "Invalid Coordinates" error if the point lies outside of known BAs. For more information on what a balancing authority is, see this explanation from the EIA.

See map coverage for available grid regions.

HTTP Request

GET https://api2.watttime.org/v2/ba-from-loc

URL Query Parameters

Response

Realtime Emissions

import requests
from requests.auth import HTTPBasicAuth

login_url = 'https://api2.watttime.org/v2/login'
token = requests.get(login_url, auth=HTTPBasicAuth('USERNAME', 'PASSWORD')).json()['token']

index_url = 'https://api2.watttime.org/index'
headers = {'Authorization': 'Bearer {}'.format(token)}
params = {'ba': 'CAISO_ZP26'}
rsp=requests.get(index_url, headers=headers, params=params)
print(rsp.text)

curl -H "Authorization: Bearer abcdef0123456789fedcabc" https://api2.watttime.org/v2/index?ba=CAISO_ZP26&style=all

Sample Response

{
    "freq": "300",   
    "ba": "MISO_MI",
    "percent": "53",
    "moer": "982.65",
    "point_time": "2019-01-29T14:55:00.00Z",
}

/index

Provides a real-time signal indicating the carbon intensity on the local grid in that moment (typically updated every 5 minutes). The current emissions rate of the grid is returned as a raw Marginal Operating Emissions Rate (MOER) value (available only to users with PRO subscriptions), or as an index value (percent), which is available to all users. This value is returned along with a ‘freq’ value, indicating how long the value is in effect. The type of value returned is set by the 'style' query parameter.

The MOER value is the lbs of CO2 per MWh produced on the grid in the specified region. The reported index percent is where the current MOER is between the min and max from the last two weeks.

HTTP Request

GET https://api2.watttime.org/v2/index

URL Query Parameters

Response

Grid Data

import requests
from requests.auth import HTTPBasicAuth

login_url = 'https://api2.watttime.org/v2/login'
token = requests.get(login_url, auth=HTTPBasicAuth('USERNAME', 'PASSWORD')).json()['token']

data_url = 'https://api2.watttime.org/v2/data'
headers = {'Authorization': 'Bearer {}'.format(token)}
params = {'ba': 'CAISO_ZP26', 
          'starttime': '2019-02-20T16:00:00-0800', 
          'endtime': '2019-02-20T16:15:00-0800'}
rsp = requests.get(data_url, headers=headers, params=params)
print(rsp.text)

curl -H "Authorization: Bearer abcdef0123456789fedcabc" https://api2.watttime.org/v2/data?ba=CAISO_NP15&starttime=2019-02-20T16:00:00-0800&endtime=2019-02-20T16:15:00-0800

Sample Response

[
{"point_time": "2019-02-21T00:15:00.000Z", "value": 844, "frequency": 300, "market": "RTM", "ba": "CAISO_ZP26", "datatype": "MOER", "version": "2.1.1"}, 
{"point_time": "2019-02-21T00:10:00.000Z", "value": 834, "frequency": 300, "market": "RTM", "ba": "CAISO_ZP26", "datatype": "MOER", "version": "2.1.1"}, 
{"point_time": "2019-02-21T00:05:00.000Z", "value": 834, "frequency": 300, "market": "RTM", "ba": "CAISO_ZP26", "datatype": "MOER", "version": "2.1.1"}, 
{"point_time": "2019-02-21T00:00:00.000Z", "value": 844, "frequency": 300, "market": "RTM", "ba": "CAISO_ZP26", "datatype": "MOER", "version": "2.1.1"}
]

/data

Obtain historical marginal emissions for a given area (balancing authority abbreviated code) or location (latitude/longitude pair).

Access to this endpoint is restricted to customers with ANALYST or PRO subscriptions. However, you can preview the data provided by using grid region CAISO_ZP26 for your requests.

HTTP Request

GET https://api2.watttime.org/v2/data

URL Query Parameters

Response

Historical Emissions

from os import path
import requests
from requests.auth import HTTPBasicAuth

login_url = 'https://api2.watttime.org/v2/login'
token = requests.get(login_url, auth=HTTPBasicAuth('USERNAME', 'PASSWORD')).json()['token']

historical_url = 'https://api2.watttime.org/v2/historical'
headers = {'Authorization': 'Bearer {}'.format(token)}
ba = 'CAISO_ZP26'
params = {'ba': ba}
rsp = requests.get(historical_url, headers=headers, params=params)
cur_dir = path.dirname(path.realpath('__file__'))
file_path = path.join(cur_dir, '{}_historical.zip'.format(ba))
with open(file_path, 'wb') as fp:
    fp.write(rsp.content)

print('Wrote historical data for {} to {}'.format(ba, file_path))

curl -H "Authorization: Bearer abcdef0123456789fedcabc" https://api2.watttime.org/v2/historical?ba=CAISO_NP15&version=latest

Sample Response

Content-Type:application/zip

/historical

Obtain a zip file containing the MOER values and timestamps for a given region for (up to) the past two years.

WattTime periodically updates the algorithms used to calculate new MOERs to add new features, incorporate new data sources, or in response to changing grid dynamics. This endpoint provides you with the option to retrieve all the MOER versions published for a given region or to retrieve only the most up-to-date version.

Historical data will be updated on the 2nd of each month at midnight UTC for the previous month.

Access to this endpoint is restricted to customers with ANALYST or PRO subscriptions.

HTTP Request

GET https://api2.watttime.org/v2/historical

URL Query Parameters

Response

Marginal Emissions Forecast

import requests
from requests.auth import HTTPBasicAuth

login_url = 'https://api2.watttime.org/v2/login'
token = requests.get(login_url, auth=HTTPBasicAuth('USERNAME', 'PASSWORD')).json()['token']

forecast_url = 'https://api2.watttime.org/v2/forecast'
headers = {'Authorization': 'Bearer {}'.format(token)}
params = {'ba': 'CAISO_NP15', 
          'starttime': '2019-02-20T16:45:30-0800', 
          'endtime': '2019-02-20T17:45:30-0800'}
rsp = requests.get(forecast_url, headers=headers, params=params)
print(rsp.text)

curl --include \
     --header "Authorization: Bearer <Access_Token>" \
  'https://api2.watttime.org/v2/forecast/?ba='

Sample Response

[
  {
    "generated_at": "2019-01-29T20:00:00.000Z", 
    "forecast": 
      [
        {
          "point_time": "2019-01-29T20:05:00.000Z",
          "ba": "MISO_IN",
          "value": 1350,
          "version": "0.0"
        },
        {
          "point_time": "2019-01-29T20:10:00.000Z",
          "ba": "MISO_IN",
          "value": 1300,
          "version": "0.0"},
         ..... <24 hours worth of datapoints>
      ]
  }
]

/forecast

Obtain MOER forecast data for a given region. Omitting the starttime and endtime parameters will return the most recently generated forecast for a given region. Use the starttime and endtime parameters to obtain historical forecast data.

Note that starttime and endtime define the time when a forecast was generated. Every five minutes, WattTime generates a new forecast which (depending on the region) is between 8 and 24 hours in duration. So, if you make a request to the forecast endpoint with starttime of Jan 1, 1:00 and endtime Jan 1, 1:05, you will receive the forecast (all 288 values in the forecast window) generated at 1:00, and the forecast generated at 1:05 on January 1.

Access to this endpoint is restricted to customers with PRO subscriptions.

HTTP Request

GET https://api2.watttime.org/v2/forecast

URL Query Parameters

Response

The value of the ‘forecast’ key is a list of dictionaries containing the following keys:

Technical Support

For technical questions related to this API and real-time emissions data, please contact support@WattTime.org