Find a supplier-specific electricity factor

Filter MITECO's default rows on has_supplier and the retailer's supplier_code, then check reference_year before you use the value. NATURGY IBERIA, S.A. declared 0.252 kg CO2e per kWh for 2025; a retailer with no row falls back to Spain's residual mix, 0.258.

The query#

supplier_code is a stable, accent-free handle for the retailer, so match on it rather than on the display name. The query also returns the residual mix, the market-based figure for electricity bought without a supplier claim.

SELECT coalesce(supplier_name, activity_full) AS supplier_or_mix,
       has_supplier,
       grid_mix,
       reference_year,
       round(value_co2e_native::numeric, 3) AS kg_co2e_per_kwh,
       data_quality_reason_normalized
FROM open_ef.factors_flat
WHERE library = 'miterd'
  AND is_default_indicator
  AND is_latest_activity_year
  AND (supplier_code LIKE 'naturgy%' OR grid_mix = 'residual')
ORDER BY has_supplier DESC, supplier_code;

One company name can cover several legal entities, each with its own factor. Use the entity on your electricity contract.

What the MITECO supplier slice holds#

SELECT count(DISTINCT supplier_id) AS suppliers,
       count(*) FILTER (WHERE value_co2e_native = 0) AS zero_rows,
       min(reference_year) AS first_year,
       max(reference_year) AS last_year,
       count(*) FILTER (WHERE reference_year = 2025) AS declared_2025
FROM open_ef.factors_flat
WHERE library = 'miterd'
  AND has_supplier
  AND is_default_indicator
  AND is_latest_activity_year
  AND is_top_parent;

Each of the 531 retailers has one default row, its most recent declaration. Only 256 of them declared for 2025; the others stopped declaring in an earlier year, as far back as 2007.

Watch out#

Watch out. The default row is the retailer's latest declaration, not this year's. NATURGY RENOVABLES last declared for 2022. Compare reference_year with your reporting year, and read a past year with the year window.

Watch out. A zero is a contractual claim, not a measurement. The 281 zero rows are green tariffs backed by Guarantees of Origin (data_quality_reason_normalized = 'green_electricity_zero'). Use one only when you hold that tariff for the electricity you report, and report the location-based figure beside it.

Why it works. has_supplier says a named company stands behind the row. grid_mix says which market instrument the value is: supplier_specific, residual or green. They are separate columns: a MITECO cogeneration Guarantee-of-Origin factor reads supplier_specific with no supplier attached, so filter on has_supplier when you want retailers.

Related#

• Market-based and location-based electricity
• Glossary: supplier, grid mix, calculation approach
• MITECO supplier factors in factor search
• MITECO coverage