owid · pabloarosado · Sep 1, 2026 · Jul 28, 2026 · Aug 21, 2026 · Aug 21, 2026
diff --git a/dag/archive/energy.yml b/dag/archive/energy.yml
@@ -1482,3 +1482,45 @@ steps:
   # archived; last active in 2a47d03292a9 on 2026-08-05
   export://explorers/energy/latest/fossil_fuels:
     - data://grapher/energy/2026-05-05/fossil_fuels
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://meadow/irena/2025-06-20/renewable_energy_patents:
+    - snapshot://irena/2025-06-20/renewable_energy_patents.csv
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://grapher/irena/2025-08-22/renewable_power_generation_costs:
+    - data://garden/irena/2025-08-22/renewable_power_generation_costs
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://meadow/irena/2025-07-18/renewable_energy_statistics:
+    - snapshot://irena/2025-07-18/renewable_energy_statistics.xlsx
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://grapher/energy/2025-08-22/photovoltaic_cost_and_capacity:
+    - data://garden/energy/2025-08-22/photovoltaic_cost_and_capacity
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://grapher/irena/2025-06-20/renewable_energy_patents:
+    - data://garden/irena/2025-06-20/renewable_energy_patents
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://garden/irena/2025-07-18/renewable_energy_statistics:
+    - data://garden/regions/2023-01-01/regions
+    - data://meadow/irena/2025-07-18/renewable_energy_statistics
+    - data://garden/wb/2026-07-01/income_groups
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://garden/irena/2025-06-20/renewable_energy_patents:
+    - data://meadow/irena/2025-06-20/renewable_energy_patents
+    - data://garden/regions/2023-01-01/regions
+    - data://garden/wb/2026-07-01/income_groups
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://grapher/irena/2025-07-18/renewable_capacity:
+    - data://garden/irena/2025-07-18/renewable_energy_statistics
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://grapher/irena/2025-07-18/renewable_capacity_by_technology:
+    - data://garden/irena/2025-07-18/renewable_energy_statistics
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://garden/irena/2025-08-22/renewable_power_generation_costs:
+    - data://meadow/irena/2025-08-22/renewable_power_generation_costs
+    - data://garden/economics/2025-08-29/owid_deflator
+    - data://meadow/irena/2024-11-15/renewable_power_generation_costs
+  # archived; last active in 4387a320d17b on 2026-08-28
+  data://garden/energy/2025-08-22/photovoltaic_cost_and_capacity:
+    - data://garden/irena/2025-07-18/renewable_energy_statistics
+    - data://garden/papers/2023-12-12/nemet_2009
+    - data://garden/irena/2025-08-22/renewable_power_generation_costs
+    - data://garden/papers/2023-12-12/farmer_lafond_2016
diff --git a/dag/economics.yml b/dag/economics.yml
@@ -18,10 +18,18 @@ steps:
         - snapshot://economics/2026-07-28/wealth_france.xlsx
 
   # OWID - OWID Deflator.
+  # NOTE: The 2025-08-29 version is kept while Lazard's levelized cost of energy step depends on it.
   data://garden/economics/2025-08-29/owid_deflator:
     # World Bank - WDI (specifically indicators used for inflation adjustments).
     - data://garden/wb/2025-08-29/wdi_prices:
       - data://meadow/wb/2025-08-29/wdi_prices:
         - snapshot://wb/2025-08-29/wdi_cpi.zip
         - snapshot://wb/2025-08-29/wdi_gdp.zip
         - snapshot://wb/2025-08-29/wdi_gdp_linked.zip
+  data://garden/economics/2026-08-21/owid_deflator:
+    # World Bank - WDI (specifically indicators used for inflation adjustments).
+    - data://garden/wb/2026-08-21/wdi_prices:
+      - data://meadow/wb/2026-08-21/wdi_prices:
+        - snapshot://wb/2026-08-21/wdi_cpi.zip
+        - snapshot://wb/2026-08-21/wdi_gdp.zip
+        - snapshot://wb/2026-08-21/wdi_gdp_linked.zip
diff --git a/dag/energy.yml b/dag/energy.yml
@@ -62,11 +62,11 @@ steps:
   #
   # IRENA - Renewable energy patents.
   #
-  data://grapher/irena/2025-06-20/renewable_energy_patents:
-    - data://garden/irena/2025-06-20/renewable_energy_patents:
+  data://grapher/irena/2026-07-28/renewable_energy_patents:
+    - data://garden/irena/2026-07-28/renewable_energy_patents:
       - data://garden/wb/2026-07-01/income_groups
-      - data://meadow/irena/2025-06-20/renewable_energy_patents:
-        - snapshot://irena/2025-06-20/renewable_energy_patents.csv
+      - data://meadow/irena/2026-07-28/renewable_energy_patents:
+        - snapshot://irena/2026-07-28/renewable_energy_patents.csv
       - data://garden/regions/2023-01-01/regions
   #
   # Energy Institute - Statistical Review of World Energy (2026, Total Energy Supply).
@@ -136,38 +136,39 @@ steps:
   #
   # IRENA - Renewable energy statistics.
   #
-  data://garden/irena/2025-07-18/renewable_energy_statistics:
+  data://garden/irena/2026-07-28/renewable_energy_statistics:
     - data://garden/regions/2023-01-01/regions
     - data://garden/wb/2026-07-01/income_groups
-    - data://meadow/irena/2025-07-18/renewable_energy_statistics:
-      - snapshot://irena/2025-07-18/renewable_energy_statistics.xlsx
-  data://grapher/irena/2025-07-18/renewable_capacity_by_technology:
-    - data://garden/irena/2025-07-18/renewable_energy_statistics
-  data://grapher/irena/2025-07-18/renewable_capacity:
-    - data://garden/irena/2025-07-18/renewable_energy_statistics
+    - data://meadow/irena/2026-07-28/renewable_energy_statistics:
+      - snapshot://irena/2026-07-28/renewable_energy_statistics.xlsx
+  data://grapher/irena/2026-07-28/renewable_capacity_by_technology:
+    - data://garden/irena/2026-07-28/renewable_energy_statistics
+  data://grapher/irena/2026-07-28/renewable_capacity:
+    - data://garden/irena/2026-07-28/renewable_energy_statistics
   #
   # IRENA - Renewable power generation costs.
   #
-  # NOTE: This step combines two versions of the data, because the latest release does not have data prior to 2010, for some reason.
-  data://garden/irena/2025-08-22/renewable_power_generation_costs:
+  # NOTE: Older releases are kept because they contain data that newer releases dropped (see the garden step).
+  data://garden/irena/2026-07-28/renewable_power_generation_costs:
+    - data://meadow/irena/2026-07-28/renewable_power_generation_costs:
+      - snapshot://irena/2026-07-28/renewable_power_generation_costs.xlsx
     - data://meadow/irena/2025-08-22/renewable_power_generation_costs:
       - snapshot://irena/2025-08-22/renewable_power_generation_costs.xlsx
-    # IRENA - Renewable power generation costs.
-    # NOTE: The following step is kept because it contains more data (mostly prior to 2010) than the latest release.
     - data://meadow/irena/2024-11-15/renewable_power_generation_costs:
       - snapshot://irena/2024-11-15/renewable_power_generation_costs.xlsx
-    - data://garden/economics/2025-08-29/owid_deflator
-  data://grapher/irena/2025-08-22/renewable_power_generation_costs:
-    - data://garden/irena/2025-08-22/renewable_power_generation_costs
+    - data://garden/economics/2026-08-21/owid_deflator
+  data://grapher/irena/2026-07-28/renewable_power_generation_costs:
+    - data://garden/irena/2026-07-28/renewable_power_generation_costs
   #
   # Energy - Photovoltaic cost and capacity.
   #
-  data://grapher/energy/2025-08-22/photovoltaic_cost_and_capacity:
-    - data://garden/energy/2025-08-22/photovoltaic_cost_and_capacity:
-      - data://garden/irena/2025-08-22/renewable_power_generation_costs
-      - data://garden/irena/2025-07-18/renewable_energy_statistics
+  data://grapher/energy/2026-07-28/photovoltaic_cost_and_capacity:
+    - data://garden/energy/2026-07-28/photovoltaic_cost_and_capacity:
+      - data://garden/irena/2026-07-28/renewable_power_generation_costs
+      - data://garden/irena/2026-07-28/renewable_energy_statistics
       - data://garden/papers/2023-12-12/nemet_2009
       - data://garden/papers/2023-12-12/farmer_lafond_2016
+      - data://garden/economics/2026-08-21/owid_deflator
   #
   # Lazard - Levelized Cost of Energy+
   #
@@ -294,5 +295,3 @@ steps:
     - data://garden/energy/2025-11-10/ireland_metered_consumption:
       - data://meadow/energy/2025-11-10/ireland_metered_consumption:
         - snapshot://energy/2025-11-10/ireland_metered_consumption.csv
-
-
diff --git a/etl/steps/data/garden/economics/2026-08-21/owid_deflator.meta.yml b/etl/steps/data/garden/economics/2026-08-21/owid_deflator.meta.yml
@@ -0,0 +1,9 @@
+dataset:
+  update_period_days: 180
+
+  owners:
+    - Pablo Rosado
+tables:
+  owid_deflator:
+    title: OWID Deflator
+    variables: {}
diff --git a/etl/steps/data/garden/economics/2026-08-21/owid_deflator.py b/etl/steps/data/garden/economics/2026-08-21/owid_deflator.py
@@ -0,0 +1,36 @@
+"""OWID Deflator dataset.
+
+This is meant to be an auxiliary dataset with indicators commonly used to do inflation adjustments.
+"""
+
+from etl.helpers import PathFinder
+
+# Get paths and naming conventions for current step.
+paths = PathFinder(__file__)
+
+
+def run() -> None:
+    #
+    # Load inputs.
+    #
+    # Load WDI auxiliary dataset with prices-related indicators, and read its table.
+    ds_wdi = paths.load_dataset("wdi_prices")
+    tb_wdi = ds_wdi.read("wdi_prices")
+
+    #
+    # Process data.
+    #
+    # Combine tables.
+    tb = tb_wdi.copy()
+
+    # Improve table format.
+    tb = tb.format(short_name=paths.short_name)
+
+    #
+    # Save outputs.
+    #
+    # Create a new garden dataset with the same metadata as the snapshot.
+    ds_garden = paths.create_dataset(tables=[tb], default_metadata=ds_wdi.metadata)
+
+    # Save changes in the new garden dataset.
+    ds_garden.save()
diff --git a/...2/photovoltaic_cost_and_capacity.meta.yml → ...8/photovoltaic_cost_and_capacity.meta.yml b/...2/photovoltaic_cost_and_capacity.meta.yml → ...8/photovoltaic_cost_and_capacity.meta.yml
@@ -23,9 +23,9 @@ tables:
         short_unit: "$/W"
         description_key:
           - "Solar photovoltaic module prices refer to the cost of the solar panel itself, and do not include installation or other system components."
-          - "Prices are compiled from three sources: Nemet (2009) for 1975-2003, Farmer & Lafond (2016) for 2004-2009, and IRENA for 2010 onward."
+          - "Prices are compiled from three sources: Nemet (2009) for 1975–2003, Farmer & Lafond (2016) for 2004–2009, and IRENA for 2010 onward."
           - "Due to limited data availability, we use the Global Price Index series reported by IRENA, based on pvXchange benchmark prices for modules sold in Europe."
-          - "Historical prices have been adjusted for inflation using the [World Bank's US GDP deflator](https://data.worldbank.org/indicator/NY.GDP.DEFL.ZS?locations=US)."
+          - "Historical prices have been adjusted for inflation using the [World Bank's US GDP deflator (linked series)](https://data.worldbank.org/indicator/NY.GDP.DEFL.ZS.AD?locations=US)."
         display:
           name: Solar PV module cost
           shortUnit: "$"
@@ -36,7 +36,7 @@ tables:
         description_processing: |-
           - Historical photovoltaic cost data between 1975 and 2003 has been taken from Nemet (2009), and between 2004 and 2009 from Farmer & Lafond (2016).
           - From 2010 onward, prices come from IRENA's Renewable Power Generation Costs report, based on pvXchange benchmarks for modules sold in Europe, using the 'Thin film a-Si/u-Si or Global Price Index (from Q4 2013)' series.
-          - Prices from Nemet (2009) and Farmer & Lafond (2016) have been converted to {LATEST_YEAR} US$ using the US GDP deflator, to account for the effects of inflation. The deflator data is available from the [World Bank World Development Indicators](https://data.worldbank.org/indicator/NY.GDP.DEFL.ZS?locations=US).
+          - Prices from Nemet (2009) and Farmer & Lafond (2016) have been converted to {LATEST_YEAR} US$ using the US GDP deflator (linked series), to account for the effects of inflation. The deflator data is available from the [World Bank World Development Indicators](https://data.worldbank.org/indicator/NY.GDP.DEFL.ZS.AD?locations=US).
       cost_source:
         title: Source for each value of cost data
         unit: ''

diff --git a/...5-08-22/photovoltaic_cost_and_capacity.py → ...6-07-28/photovoltaic_cost_and_capacity.py b/...5-08-22/photovoltaic_cost_and_capacity.py → ...6-07-28/photovoltaic_cost_and_capacity.py
@@ -26,15 +26,24 @@
 # Get paths and naming conventions for current data step.
 paths = PathFinder(__file__)
 
-# Conversion factors.
 # IRENA costs are given in the latest year's USD, so we convert other costs to the same currency.
-LATEST_YEAR = 2024
-# Convert 2004 USD and 2013 USD to LATEST_YEAR USD using the World Bank's GDP deflator:
-# https://data.worldbank.org/indicator/NY.GDP.DEFL.ZS.AD?locations=US
-# Download the excel file, and divide the value for the latest year by the value of 2004 (79.0769459998626):
-USD2004_TO_USDLATEST = 1.58
-# Similarly, divide the value for the latest year by the value of 2013 (94.7705183765681):
-USD2013_TO_USDLATEST = 1.32
+LATEST_YEAR = 2025
+
+
+def get_usd_conversion_factor(from_year: int) -> float:
+    """Get the factor to convert constant US$ of a given year into constant US$ of LATEST_YEAR, using the US GDP
+    deflator (linked series).
+
+    NOTE: The factor is returned as a plain float so that the deflator's metadata (from WDI, which is used as an
+    auxiliary dataset) does not propagate into the indicators.
+    """
+    ds_deflator = paths.load_dataset("owid_deflator")
+    tb_deflator = ds_deflator.read("owid_deflator")
+    us = tb_deflator[tb_deflator["country"] == "United States"].set_index("year")["gdp_deflator_linked"]
+    factor = float(us.loc[LATEST_YEAR] / us.loc[from_year])
+    assert 1.0 <= factor < 2.0, f"Unexpected US deflator factor from {from_year} to {LATEST_YEAR}."
+
+    return factor
 
 
 def prepare_capacity_data(tb_nemet: Table, tb_irena_capacity: Table) -> Table:
@@ -85,7 +94,7 @@ def prepare_cost_data(tb_nemet: Table, tb_irena_cost: Table, tb_farmer_lafond: T
     tb_nemet_cost = tb_nemet[["year", "cost"]].copy()
     tb_nemet_cost["cost_source"] = "Nemet (2009)"
     # Costs are given in "2004 USD/watt", so we need to convert them to the latest year USD.
-    tb_nemet_cost["cost"] *= USD2004_TO_USDLATEST
+    tb_nemet_cost["cost"] *= get_usd_conversion_factor(from_year=2004)
     tb_nemet_cost["cost"].metadata.unit = f"constant {LATEST_YEAR} US$ per watt"
 
     # Prepare solar photovoltaic cost data from Farmer & Lafond (2016).
@@ -97,16 +106,18 @@ def prepare_cost_data(tb_nemet: Table, tb_irena_cost: Table, tb_farmer_lafond: T
     )
     tb_farmer_lafond["cost_source"] = "Farmer & Lafond (2016)"
     # Costs are given in "2013 USD/Wp", so we need to convert them to the latest year USD.
-    tb_farmer_lafond["cost"] *= USD2013_TO_USDLATEST
+    tb_farmer_lafond["cost"] *= get_usd_conversion_factor(from_year=2013)
     tb_farmer_lafond["cost"].metadata.unit = f"constant {LATEST_YEAR} US$ per watt"
 
     # Prepare solar photovoltaic cost data from IRENA.
     tb_irena_cost = tb_irena_cost.drop(columns="country", errors="raise")
 
     tb_irena_cost["cost_source"] = "IRENA"
     # Costs are given in latest year "USD/W", so we do not need to correct them.
+    # NOTE: The series ends in 2024 (IRENA discontinued the global module price index after the Renewable Power
+    #  Generation Costs in 2024 report), but its values are expressed in constant US$ of LATEST_YEAR.
     error = "IRENA data has changed, prices may need to be deflated to the latest year."
-    assert tb_irena_cost["year"].max() == LATEST_YEAR, error
+    assert tb_irena_cost["cost"].metadata.unit == f"constant {LATEST_YEAR} US$ per watt", error
 
     # Combine Nemet (2009) and Farmer & Lafond (2016), prioritizing the former.
     combined = combine_two_overlapping_dataframes(df1=tb_nemet_cost, df2=tb_farmer_lafond, index_columns="year")