Migrate NREL references to NLR (National Laboratory of the Rockies)

Update all nrel.gov URLs to nlr.gov equivalents following the NREL→NLR
rename (Dec 2025). The nrel.gov domain stops resolving May 29, 2026.

- Update API base URLs in psm4.py and midc.py (critical runtime paths)
- Add NLR_API_KEY env var support with NREL_API_KEY deprecation fallback
- Update all documentation URLs, prose references, and test comments
- Preserve report IDs (NREL/TP-xxx), GitHub URLs, and citation publishers

Closes #2701

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jason-curtis

.github/workflows/pytest-remote-data.yml

@@ -96,6 +96,7 @@ jobs:
         shell: bash -l {0}  # necessary for conda env to be active
         env:
           # copy GitHub Secrets into environment variables for the tests to access
+          NLR_API_KEY: ${{ secrets.NRELAPIKEY }}
           NREL_API_KEY: ${{ secrets.NRELAPIKEY }}
           SOLARANYWHERE_API_KEY: ${{ secrets.SOLARANYWHERE_API_KEY }}
           BSRN_FTP_USERNAME: ${{ secrets.BSRN_FTP_USERNAME }}

docs/examples/irradiance-decomposition/plot_diffuse_fraction.py

@@ -52,7 +52,7 @@
 # ----
 #
 # DISC :py:func:`~pvlib.irradiance.disc` is an empirical correlation developed
-# at SERI (now NREL) in 1987. The direct normal irradiance (DNI) is related to
+# at SERI (now NLR) in 1987. The direct normal irradiance (DNI) is related to
 # clearness index (kt) by two polynomials split at kt = 0.6, then combined with
 # an exponential relation with airmass.
 
@@ -216,5 +216,5 @@
 # correlations, which include additional variables such as airmass. These
 # methods seem to reduce DNI spikes over 1000 [W/m^2].
 #
-# .. _TMY3: https://www.nrel.gov/docs/fy08osti/43156.pdf
-# .. _NSRDB: https://www.nrel.gov/docs/fy12osti/54824.pdf
+# .. _TMY3: https://www.nlr.gov/docs/fy08osti/43156.pdf
+# .. _NSRDB: https://www.nlr.gov/docs/fy12osti/54824.pdf

docs/examples/spectrum/average_photon_energy.py

@@ -34,7 +34,7 @@
 from scipy.integrate import trapezoid
 from pvlib import spectrum, solarposition, irradiance, atmosphere
 
-lat, lon = 39.742, -105.18  # NREL SRRL location
+lat, lon = 39.742, -105.18  # NLR SRRL location
 surface_tilt = 25
 surface_azimuth = 180  # south-facing system
 pressure = 81190  # at 1828 metres AMSL, roughly
@@ -194,5 +194,5 @@
 #        for the solar spectral influence on photovoltaic device performance."
 #        Energy 286 :doi:`10.1016/j.energy.2023.129461`
 # .. [4] Bird Simple Spectral Model: spectrl2_2.c
-#        https://www.nrel.gov/grid/solar-resource/spectral.html
+#        https://www.nlr.gov/grid/solar-resource/spectral.html
 #        (Last accessed: 18/09/2024)

docs/examples/spectrum/plot_spectrl2_fig51A.py

@@ -2,15 +2,15 @@
 Modeling Spectral Irradiance
 ============================
 
-Recreating Figure 5-1A from the SPECTRL2 NREL Technical Report.
+Recreating Figure 5-1A from the SPECTRL2 NLR Technical Report.
 """
 
 # %%
 # This example shows how to model the spectral distribution of irradiance
 # based on atmospheric conditions. The spectral distribution of irradiance is
 # the power content at each wavelength band in the solar spectrum and is
 # affected by various scattering and absorption mechanisms in the atmosphere.
-# This example recreates an example figure from the SPECTRL2 NREL Technical
+# This example recreates an example figure from the SPECTRL2 NLR Technical
 # Report [1]_. The figure shows modeled spectra at hourly intervals across
 # a single morning.
 
@@ -95,5 +95,5 @@
 # ----------
 # .. [1] Bird, R, and Riordan, C., 1984, "Simple solar spectral model for
 #    direct and diffuse irradiance on horizontal and tilted planes at the
-#    earth's surface for cloudless atmospheres", NREL Technical Report
+#    earth's surface for cloudless atmospheres", NLR Technical Report
 #    TR-215-2436 :doi:`10.2172/5986936`

docs/sphinx/source/reference/iotools.rst

@@ -179,7 +179,7 @@ A solar radiation network in the USA, run by NOAA.
 MIDC
 ^^^^
 
-A solar radiation network in the USA, run by NREL.
+A solar radiation network in the USA, run by NLR.
 
 .. autosummary::
    :toctree: generated/

docs/sphinx/source/reference/solarposition.rst

@@ -43,7 +43,7 @@ Functions for calculating sunrise, sunset and transit times.
    solarposition.sun_rise_set_transit_geometric
 
 
-The spa module contains the implementation of the built-in NREL SPA
+The spa module contains the implementation of the built-in NLR SPA
 algorithm.
 
 .. autosummary::

docs/sphinx/source/user_guide/getting_started/installation.rst

@@ -235,22 +235,22 @@ Alternatively, users may install all optional dependencies using
 
 .. _nrelspa:
 
-NREL SPA algorithm
+NLR SPA algorithm
 ------------------
 
 pvlib-python is distributed with several validated, high-precision, and
 high-performance solar position calculators. We strongly recommend using
 the built-in solar position calculators.
 
-pvlib-python also includes unsupported wrappers for the official NREL
-SPA algorithm. NREL's license does not allow redistribution of the
+pvlib-python also includes unsupported wrappers for the official NLR
+SPA algorithm. NLR's license does not allow redistribution of the
 source code, so you must jump through some hoops to use it with pvlib.
 You will need a C compiler to use this code.
 
-To install the NREL SPA algorithm for use with pvlib:
+To install the NLR SPA algorithm for use with pvlib:
 
 #. Download the pvlib repository (as described in :ref:`obtainsource`)
-#. Download the `SPA files from NREL <http://www.nrel.gov/midc/spa/>`_
+#. Download the `SPA files from NLR <http://www.nlr.gov/midc/spa/>`_
 #. Copy the SPA files into ``pvlib-python/pvlib/spa_c_files``
 #. From the ``pvlib-python`` directory, run ``pip uninstall pvlib``
    followed by ``pip install .``

docs/sphinx/source/whatsnew/v0.15.1.rst

@@ -56,6 +56,10 @@ Requirements
 
 Maintenance
 ~~~~~~~~~~~
+* Update all NREL references to NLR (National Laboratory of the Rockies)
+  following the laboratory rename and domain migration from ``nrel.gov``
+  to ``nlr.gov``. Add ``NLR_API_KEY`` environment variable support with
+  ``NREL_API_KEY`` fallback. (:issue:`2701`)
 
 
 Contributors

docs/tutorials/tmy_to_power.ipynb

@@ -70,11 +70,7 @@
   {
    "cell_type": "markdown",
    "metadata": {},
-   "source": [
-    "pvlib comes with a couple of TMY files, and we'll use one of them for simplicity. You could also load a file from disk, or specify a url. See this NREL website for a list of TMY files:\n",
-    "\n",
-    "http://rredc.nrel.gov/solar/old_data/nsrdb/1991-2005/tmy3/by_state_and_city.html"
-   ]
+   "source": "pvlib comes with a couple of TMY files, and we'll use one of them for simplicity. You could also load a file from disk, or specify a url. See this NLR website for a list of TMY files:\n\nhttp://rredc.nlr.gov/solar/old_data/nsrdb/1991-2005/tmy3/by_state_and_city.html"
   },
   {
    "cell_type": "code",
@@ -1515,13 +1511,7 @@
   {
    "cell_type": "markdown",
    "metadata": {},
-   "source": [
-    "Next, we will assume that the SAPM model is representative of the real world performance so that we can use scipy's optimization routine to derive simulated PVUSA coefficients. You will need to install scipy to run these functions.\n",
-    "\n",
-    "Here's one PVUSA reference:\n",
-    "\n",
-    "http://www.nrel.gov/docs/fy09osti/45376.pdf\n"
-   ]
+   "source": "Next, we will assume that the SAPM model is representative of the real world performance so that we can use scipy's optimization routine to derive simulated PVUSA coefficients. You will need to install scipy to run these functions.\n\nHere's one PVUSA reference:\n\nhttp://www.nlr.gov/docs/fy09osti/45376.pdf\n"
   },
   {
    "cell_type": "code",
@@ -1667,4 +1657,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 4
-}
+}

pvlib/atmosphere.py

@@ -448,7 +448,7 @@ def bird_hulstrom80_aod_bb(aod380, aod500):
     References
     ----------
     .. [1] Bird and Hulstrom, "Direct Insolation Models" (1980)
-       `SERI/TR-335-344 <http://www.nrel.gov/docs/legosti/old/344.pdf>`_
+       `SERI/TR-335-344 <http://www.nlr.gov/docs/legosti/old/344.pdf>`_
 
     .. [2] R. E. Bird and R. L. Hulstrom, "Review, Evaluation, and Improvement
        of Direct Irradiance Models", Journal of Solar Energy Engineering