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The Offshore California Dataset is a 21-year wind resource dataset for offshore California. Produced in 2020, this data set replaces NREL's Wind Integration National Dataset (WIND) Toolkit for offshore California, which was produced and released publicly in 2013 and is currently the principal data set used by stakeholders for wind resource assessment in the continental United States. Both the WIND Toolkit and this new data set are created using the Weather Research and Forecasting (WRF) numerical weather prediction model (NWP).

This API is capable of creating very large downloadable archives. Unlike a typical API, the response to this provides a request acknowledgement. The real work of creating the requested downloadable archive will continue to run on the server side. When complete, and email will be sent to the email address provided in the initial request with a link to a file to download. In addition to this two step workflow, there is also an option for users who wish to download a single CSV file in direct response to an API request. The .csv format may be used to download a CSV directly. This feature is restricted to use with only a single POINT, for a single YEAR at a time.

The Offshore CA shares many of the same attributes as the WIND Toolkit, including 5-minute time resolution and 2-kilometer horizontal spatial resolution. However, the new data set improves upon - the WIND Toolkit through:

Request URL

GET /api/wind-toolkit/v2/wind/offshore-ca-download.format?parameters

Request Parameters

Parameter Required Value Description
api_key Yes
Type: string
Default: None

Your developer API key. See API keys for more information.

wkt Yes
Type: well-known text point string
Default: None
A well-known text (WKT) representation of the geometry for which to extract data. May be a point or polygon geometry.
attributes Yes
Type: comma delimited string array
Default: None
Options: friction_velocity_2m, inversemoninobukhovlength_2m, roughness_length, surface_sea_temperature, pressure_0m, pressure_100m, pressure_200m, relativehumidity_2m, precipitationrate_0m, windspeed_10m, windspeed_40m, windspeed_60m, windspeed_80m, windspeed_100m, windspeed_120m, windspeed_140m, windspeed_160m, windspeed_180m, windspeed_200m, winddirection_10m, winddirection_20m, winddirection_40m, winddirection_60m, winddirection_80m, winddirection_100m, winddirection_120m, winddirection_140m, winddirection_160m, winddirection_180m, winddirection_200m, temperature_2m, temperature_10m, temperature_20m, temperature_40m, temperature_60m, temperature_80m, temperature_100m, temperature_120m, temperature_140m, temperature_160m, temperature_180m, temperature_200m, wind_speed, wind_direction, pressure, temperature
Each specified attribute will be returned as a column in the resultant CSV download.
names Yes
Type: comma delimited integer array
Default: None
Options: 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020
The year(s) for which data should be extracted.
interval No
Type: integer
Default: 5
Options: 5, 15, 30, 60
Desired data timestep resolution in minutes.
utc No
Type: true or false
Default: true
Pass true to retrieve data with timestamps in UTC. Pass false to retrieve data with timestamps converted to local time of data point (without daylight savings time).
leap_day No
Type: true or false
Default: false
Pass true to retrieve data including leap day (where appropriate). Pass false to retrieve data excluding leap day.
full_name No
Type: string
Default: None
 
The full name of the user requesting data.
email Yes
Type: email string
Default: None
 
An active email for the user requesting data. This email will be used to deliver the extracted data.
affiliation No
Type: string
Default: None
 
The organization with which the user requesting the data is affiliated.
reason No
Type: string
Default: None
 
The reason that the user is requesting the data.

Response Fields

The response is composed of service-related informational fields and the results of the data query.

Field Value Description
errors
Type: string array

A list of error messages

inputs
Type: Object Hash
Key: Value pairs representing all input parameters
outputs
Type: Object Hash
Upon successful completion a message will be returned informing the user that file generation is in progress and an email will be sent to the address provided in the email input field when the download is ready

Examples

GET /api/wind-toolkit/v2/wind/offshore-ca-download.json?wkt=POINT (-128.77481 39.970406)&attributes=wind_speed,wind_direction&names=2017&utc=false&leap_day=true&full_name=Data%20Lover&email=data.lover%40gmail.com&affiliation=NREL
{
    "inputs": {
				"wkt": "POINT (-128.77481 39.970406)",
				"attributes": "wind_speed,wind_direction",
				"names": "2017",
				"utc": "false",
				"leap_day": "true",
        "email": "user@company.com"
    },
    "metadata": {
        "version": "2.0.0",
        "resultset": {
            "count": 1
        }
    },
    "status": 200,
    "outputs": {
        "message": "File generation in progress. An email will be sent to user@company.com when the download is ready.",
        "downloadUrl": "https://mapfiles.nrel.gov/data/wind/8f15cfd44948cb76e7cf9531d5fe9cde.zip"
    },
    "errors": []
}
GET /api/wind-toolkit/v2/wind/offshore-ca-download.csv?wkt=POINT (-128.77481 39.970406)&attributes=wind_speed,wind_direction&names=2017&utc=false&leap_day=true&full_name=Data%20Lover&email=data.lover%40gmail.com&affiliation=NREL
SiteID,1,Site Timezone,-9,Data Timezone,,Longitude,-128.77481,Latitude,39.970406
Year,Month,Day,Hour,Minute,wind speed at 100m (m/s),wind direction at 100m (deg)
2017,1,1,0,30,13.35,6.41
2017,1,1,1,30,13.13,3.59
2017,1,1,2,30,13.290000000000001,358.89
2017,1,1,3,30,12.13,359.18
2017,1,1,4,30,12.81,357.96
2017,1,1,5,30,11.78,355.59000000000003
2017,1,1,6,30,11.57,350.11
2017,1,1,7,30,12.71,358.08

Rate Limits

Rate limits for this application are significantly less than the standard rate limits for developer.nrel.gov. This decrease in the limit is required as the data provided through this service is significantly more computationally intensive to generate and provide. These rate limits are carefully calculated to allow all users the maximum throughput that our servers can sustain.

There are several levels of rate limiting for this service. The first limit determines how many requests a given user can make per 24 hour period. For requests utilizing the .csv format this rate limit is set at 5000 a day at a frequency of no more than 1 per second. For all other requests this limit is set at 1000 requests per day at a frequency of no more than 1 every 2 seconds.

Secondly each user is limited to 20 in-flight requests at any given time.

In addition, the service has a fail-safe mechanism to prevent significant performance decreases that can be caused by unexpectedly high usage of the service. This limit will cause the service to stop accepting requests when the queue reaches a point where additional requests will significantly lower server performance. When this limit is hit, the service will error with a message describing that the request queue is full.

For some tips and tricks to maximize data downloads please read the guide here.

Contact

For questions about the API or the data models please contact WindToolkit@nrel.gov

Errors

Standard errors may be returned. In addition, the following service-specific errors may be returned:

HTTP Status Code Description
400 Bad Request: When required parameters are missing.
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