Highly Scalable Data Service (HSDS)

The Highly Scalable Data Service (HSDS) is a cloud-optimized solution for storing and accessing HDF5 files, e.g. the NREL wind and solar datasets. You can access NREL data via HSDS in a few ways. Read below to find out more.

NREL Developer API

The easiest way to get started with HSDS is to get a developer API key via the NREL Developer Network. Once you have your API key, create an HSDS config file at ~/.hscfg with the following entries (make sure you update the hs_api_key entry):

# NREL dev api
hs_endpoint = https://developer.nrel.gov/api/hsds
hs_api_key = your_api_key_goes_here

You should then be able to access NREL hsds data using rex and h5pyd as per the usage examples below. Note that this API is hosted on an NREL server and will have limits on the amount of data you can access via HSDS. If you get a the OSError: Error retrieving data: None errors, it’s probably because you’re hitting the public IO limits. You can confirm this by trying to extract a very small amount of data with h5pyd like this:

import h5pyd
nsrdb_file = '/nrel/nsrdb/v3/nsrdb_2018.h5'
with h5pyd.File(nsrdb_file) as f:
  data = f['ghi'][0, 0]

If this simple query succeeds while larger data slices fail, it is almost definitely a limitation of the public API. You’ll need to stand up your own HSDS server to retrieve more data. Read the section on “Setting up a Local HSDS Server” below to find out how.

Setting up a Local HSDS Server

Setting up an HSDS server on an EC2 instance or your local machine isn’t too hard. The instruction set here is intended to be comprehensive and followed exactly. Most of these instructions are adapted from the HSDS Repository and the h5pyd repository, but this tutorial is intended to be comprehensive and regularly maintained for NREL use. Please note the minor differences in the Unix- and Windows-specific instructions below and be sure to follow these subtleties exactly!

Make sure you have python 3.x (we recommend 3.10), pip, and git installed. We find it easiest to manage your HSDS environment by installing miniconda and creating a clean HSDS environment. Once you have that setup, follow these instructions:

  1. In your shell, install nrel-rex >= v0.2.86 using pip (this should also install HSDS and h5pyd).

    pip install "nrel-rex>=0.2.86"
  2. Set your environment variables (if using windows, use set instead of export) (this has to be done every time you login to a shell unless you set these in your .bashrc):

    export AWS_S3_GATEWAY=http://s3.us-west-2.amazonaws.com
    export AWS_S3_NO_SIGN_REQUEST=1
  3. Create a HSDS configuration file at ~/.hscfg (you can also use the hsconfigure CLI utility) with ONLY the following entries:

    # Local HSDS server
    hs_endpoint = http://localhost:5101
    hs_bucket = nrel-pds-hsds
  4. Start your HSDS local server in the active shell by running the command $ hsds

  5. If you are on windows and see a “Windows Security Alert” pop up, check the box for “Private networks” and click “Allow access”

  6. After a few seconds, you should see the HSDS local server print the successful status READY! use endpoint: http://localhost:5101

  7. Open a new shell instance, activate the HSDS python environment you’ve been using, and run $ hsinfo. You should see something similar to the following if your local HSDS server is running correctly:

    server name: Highly Scalable Data Service (HSDS)
    server state: READY
    endpoint: http://localhost:5101
    username: anonymous
    server version: 0.8.4
    node count: 4
    up: 53 sec
    h5pyd version: 0.18.0
  8. If you see this successful message, you can move on. If hsinfo fails, something went wrong in the previous steps.

  9. Test that h5pyd is configured correctly by running the following python script. You can also use the HSDS CLI utility $ hsls /nrel/

    import h5pyd
    with h5pyd.Folder('/nrel/') as f:
  10. Assuming you see a list of NREL public dataset directories (e.g. ['nsrdb', 'wtk', ...], congratulations! You have setup HSDS and h5pyd correctly.

HSDS and rex Usage Examples

Now that you have an HSDS server running locally and h5pyd set up, you can access NREL data as if you were on the NREL supercomputer. First, start by browsing the NREL HSDS data offerings by exploring the HSDS folder structure:

import h5pyd
with h5pyd.Folder('/nrel/') as f:

with h5pyd.Folder('/nrel/nsrdb/') as f:

with h5pyd.Folder('/nrel/wtk/') as f:

These commands can also be run by using the HSDS CLI utility: $ hsls /nrel/.

Once you find a file you want to access, you can use the rex utilities to read the data. See the docs page here for more details.