diff --git a/electricitymap/contrib/parsers/CZ.py b/electricitymap/contrib/parsers/CZ.py
index 736d553207..041b15afb9 100644
--- a/electricitymap/contrib/parsers/CZ.py
+++ b/electricitymap/contrib/parsers/CZ.py
@@ -4,7 +4,7 @@
 from bs4 import BeautifulSoup
 
 # The request library is used to fetch content through HTTP
-from requests import Response, Session
+from requests import RequestException, Response, Session
 
 from electricitymap.contrib.lib.models.event_lists import (
     ExchangeList,
@@ -74,6 +74,72 @@ def get_target_datetime(dt: datetime | None) -> datetime:
     return dt
 
 
+def build_payload(
+    method: str,
+    date_from: datetime,
+    date_to: datetime,
+    para1: str | None = None,
+) -> str:
+    para1_tag = f"<para1>{para1}</para1>" if para1 is not None else ""
+    return f"""<?xml version="1.0" encoding="utf-8"?>
+    <soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
+      <soap12:Body>
+        <{method} xmlns="https://www.ceps.cz/CepsData/">
+          <dateFrom>{date_from.isoformat()}</dateFrom>
+          <dateTo>{date_to.isoformat()}</dateTo>
+          <agregation>QH</agregation>
+          <function>AVG</function>
+          <version>RT</version>
+          {para1_tag}
+        </{method}>
+      </soap12:Body>
+    </soap12:Envelope>"""
+
+
+def get_pumping_by_datetime(
+    session: Session,
+    date_from: datetime,
+    date_to: datetime,
+    zone_key: ZoneKey,
+    logger: Logger,
+) -> dict[datetime, float]:
+    """Derive pumped storage pumping per interval from the CEPS Load data,
+    as the difference between the "Load including pumping" and "Load" series.
+
+    Pumping is an optional enrichment: failures degrade to production
+    without pumped storage consumption instead of aborting the fetch.
+    """
+    try:
+        payload = build_payload("Load", date_from, date_to)
+        content = make_request(session, payload, zone_key).text
+        xml = BeautifulSoup(content, "xml")
+        mapper = get_mapper(xml) if xml.find("series") is not None else {}
+        data_tag = xml.find("data")
+
+        if (
+            data_tag is not None
+            and "Load including pumping" in mapper
+            and "Load" in mapper
+        ):
+            pumping_by_datetime: dict[datetime, float] = {}
+            for values in data_tag:
+                load_including_pumping = float(values[mapper["Load including pumping"]])
+                load = float(values[mapper["Load"]])
+                # guard against negative rounding artifacts in the source
+                pumping = max(0.0, load_including_pumping - load)
+                pumping_by_datetime[datetime.fromisoformat(values["date"])] = pumping
+            return pumping_by_datetime
+        failure = "no Load series in the response"
+    except (AssertionError, RequestException, KeyError, ValueError) as error:
+        failure = str(error)
+
+    logger.warning(
+        f"CZ.py: no usable Load data between {date_from} and {date_to} "
+        f"({failure}), pumped storage consumption will be missing"
+    )
+    return {}
+
+
 def __get_exchange_data(
     zone_key1: ZoneKey = ZoneKey("CZ"),
     zone_key2: ZoneKey = ZoneKey("DE"),
@@ -146,30 +212,20 @@ def fetch_production(
     session: Session = Session(),
     target_datetime: datetime | None = None,
     logger: Logger = getLogger(__name__),
-) -> list:
+) -> list[dict]:
     target_datetime = get_target_datetime(target_datetime)
     from_datetime = target_datetime - timedelta(hours=48)
 
-    payload = """<?xml version="1.0" encoding="utf-8"?>
-            <soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
-              <soap12:Body>
-                <Generation xmlns="https://www.ceps.cz/CepsData/">
-                  <dateFrom>{}</dateFrom>
-                  <dateTo>{}</dateTo>
-                  <agregation>{}</agregation>
-                  <function>{}</function>
-                  <version>{}</version>
-                  <para1>{}</para1>
-                </Generation>
-              </soap12:Body>
-            </soap12:Envelope>""".format(
-        from_datetime.isoformat(), target_datetime.isoformat(), "QH", "AVG", "RT", "all"
-    )
+    payload = build_payload("Generation", from_datetime, target_datetime, para1="all")
 
     content = make_request(session, payload, zone_key).text
     xml = BeautifulSoup(content, "xml")
     mapper = get_mapper(xml)
 
+    pumping_by_datetime = get_pumping_by_datetime(
+        session, from_datetime, target_datetime, zone_key, logger
+    )
+
     data_tag = xml.find("data")
     production_breakdowns = ProductionBreakdownList(logger)
 
@@ -177,6 +233,7 @@ def fetch_production(
         for values in data_tag:
             production = ProductionMix()
             storage = StorageMix()
+            event_datetime = datetime.fromisoformat(values["date"])
 
             for k, v in mapper.items():
                 generator = translate_table_gen[k]
@@ -185,16 +242,21 @@ def fetch_production(
                 else:
                     storage.add_value(mode=generator, value=float(values[v]) * -1)
 
+            pumping = pumping_by_datetime.get(event_datetime)
+            if pumping is not None:
+                # net hydro storage = pumping - pumped storage generation
+                storage.add_value(mode="hydro", value=pumping)
+
             production_breakdowns.append(
                 zoneKey=zone_key,
-                datetime=datetime.fromisoformat(values["date"]),
+                datetime=event_datetime,
                 source=source,
                 production=production,
                 storage=storage,
             )
 
     else:
-        ParserException(
+        raise ParserException(
             "CZ.py",
             f"There was no data returned for {zone_key} at {target_datetime}",
             zone_key,
diff --git a/electricitymap/contrib/parsers/tests/__snapshots__/test_CZ/test_fetch_production.ambr b/electricitymap/contrib/parsers/tests/__snapshots__/test_CZ/test_fetch_production.ambr
new file mode 100644
index 0000000000..a8c62d1636
--- /dev/null
+++ b/electricitymap/contrib/parsers/tests/__snapshots__/test_CZ/test_fetch_production.ambr
@@ -0,0 +1,555 @@
+# serializer version: 1
+# name: test_fetch_production
+  list([
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 6, 0, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 138.1,
+        'coal': 3633.2,
+        'gas': 1015.9,
+        'hydro': 55.5,
+        'nuclear': 4128.0,
+        'solar': 153.4,
+        'unknown': 0.0,
+        'wind': 35.1,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 6, 15, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 139.0,
+        'coal': 3637.7,
+        'gas': 1026.6,
+        'hydro': 55.9,
+        'nuclear': 4129.8,
+        'solar': 220.5,
+        'unknown': 0.0,
+        'wind': 31.5,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 6, 30, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 138.2,
+        'coal': 3637.3,
+        'gas': 1043.5,
+        'hydro': 55.9,
+        'nuclear': 4129.0,
+        'solar': 276.4,
+        'unknown': 0.0,
+        'wind': 27.2,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': -162.5,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 6, 45, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 137.8,
+        'coal': 3643.3,
+        'gas': 1046.9,
+        'hydro': 55.9,
+        'nuclear': 4128.5,
+        'solar': 347.3,
+        'unknown': 0.0,
+        'wind': 21.8,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': -162.5,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 7, 0, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 137.5,
+        'coal': 3639.8,
+        'gas': 1050.9,
+        'hydro': 78.0,
+        'nuclear': 4127.3,
+        'solar': 421.0,
+        'unknown': 0.0,
+        'wind': 26.8,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': -160.1,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 7, 15, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 136.1,
+        'coal': 3641.1,
+        'gas': 1052.2,
+        'hydro': 81.3,
+        'nuclear': 4127.7,
+        'solar': 537.9,
+        'unknown': 0.0,
+        'wind': 26.1,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': -166.4,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 7, 30, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 136.1,
+        'coal': 3651.9,
+        'gas': 1052.2,
+        'hydro': 81.3,
+        'nuclear': 4128.6,
+        'solar': 643.9,
+        'unknown': 0.0,
+        'wind': 32.3,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 7, 45, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 136.4,
+        'coal': 3656.7,
+        'gas': 1047.4,
+        'hydro': 80.2,
+        'nuclear': 4129.6,
+        'solar': 746.2,
+        'unknown': 0.0,
+        'wind': 30.5,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 8, 0, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 136.5,
+        'coal': 3621.0,
+        'gas': 1021.2,
+        'hydro': 66.7,
+        'nuclear': 4131.1,
+        'solar': 811.3,
+        'unknown': 0.0,
+        'wind': 31.6,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 8, 15, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 136.8,
+        'coal': 3614.0,
+        'gas': 1024.4,
+        'hydro': 66.5,
+        'nuclear': 4127.9,
+        'solar': 914.4,
+        'unknown': 0.0,
+        'wind': 39.2,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 8, 30, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 136.4,
+        'coal': 3651.8,
+        'gas': 1018.4,
+        'hydro': 66.5,
+        'nuclear': 4124.9,
+        'solar': 982.6,
+        'unknown': 0.0,
+        'wind': 39.7,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 8, 45, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 136.5,
+        'coal': 3684.8,
+        'gas': 1016.3,
+        'hydro': 64.8,
+        'nuclear': 4121.4,
+        'solar': 1056.0,
+        'unknown': 0.0,
+        'wind': 27.6,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 9, 0, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 135.6,
+        'coal': 3658.1,
+        'gas': 1008.6,
+        'hydro': 44.2,
+        'nuclear': 4118.7,
+        'solar': 1148.7,
+        'unknown': 0.0,
+        'wind': 25.3,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 9, 15, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 136.4,
+        'coal': 3649.9,
+        'gas': 980.3,
+        'hydro': 43.7,
+        'nuclear': 4114.5,
+        'solar': 1176.8,
+        'unknown': 0.0,
+        'wind': 27.7,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 9, 30, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 136.8,
+        'coal': 3660.9,
+        'gas': 889.4,
+        'hydro': 43.7,
+        'nuclear': 4111.9,
+        'solar': 1243.0,
+        'unknown': 0.0,
+        'wind': 39.8,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 9, 45, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 137.4,
+        'coal': 3663.4,
+        'gas': 823.4,
+        'hydro': 43.7,
+        'nuclear': 4110.1,
+        'solar': 1319.5,
+        'unknown': 0.0,
+        'wind': 38.0,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 10, 0, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 137.0,
+        'coal': 3671.2,
+        'gas': 820.4,
+        'hydro': 43.7,
+        'nuclear': 4107.8,
+        'solar': 1408.9,
+        'unknown': 0.0,
+        'wind': 33.0,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 10, 15, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 137.3,
+        'coal': 3667.5,
+        'gas': 821.2,
+        'hydro': 43.7,
+        'nuclear': 4107.2,
+        'solar': 1500.9,
+        'unknown': 0.0,
+        'wind': 27.0,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 10, 30, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 137.7,
+        'coal': 3668.6,
+        'gas': 826.3,
+        'hydro': 43.7,
+        'nuclear': 4106.1,
+        'solar': 1587.7,
+        'unknown': 0.0,
+        'wind': 26.2,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 0.0,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 10, 45, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 138.3,
+        'coal': 3657.7,
+        'gas': 811.5,
+        'hydro': 43.7,
+        'nuclear': 4103.4,
+        'solar': 1686.6,
+        'unknown': 0.0,
+        'wind': 26.0,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 1.399,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 11, 0, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 138.8,
+        'coal': 3658.8,
+        'gas': 825.3,
+        'hydro': 43.7,
+        'nuclear': 4102.2,
+        'solar': 1723.9,
+        'unknown': 0.0,
+        'wind': 27.8,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 104.799,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 11, 15, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 138.6,
+        'coal': 3654.7,
+        'gas': 825.3,
+        'hydro': 43.7,
+        'nuclear': 4102.2,
+        'solar': 1774.9,
+        'unknown': 0.0,
+        'wind': 35.1,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 105.2,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 11, 30, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 138.7,
+        'coal': 3645.4,
+        'gas': 805.4,
+        'hydro': 43.7,
+        'nuclear': 4102.7,
+        'solar': 1874.2,
+        'unknown': 0.0,
+        'wind': 38.8,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 154.867,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 11, 45, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 138.6,
+        'coal': 3643.8,
+        'gas': 799.7,
+        'hydro': 43.7,
+        'nuclear': 4103.1,
+        'solar': 1880.3,
+        'unknown': 0.0,
+        'wind': 40.7,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 474.732,
+      }),
+      'zoneKey': 'CZ',
+    }),
+    dict({
+      'correctedModes': list([
+      ]),
+      'datetime': datetime.datetime(2026, 7, 1, 12, 0, tzinfo=datetime.timezone(datetime.timedelta(seconds=7200))),
+      'end_datetime': None,
+      'production': dict({
+        'biomass': 137.9,
+        'coal': 3603.2,
+        'gas': 798.0,
+        'hydro': 43.7,
+        'nuclear': 4104.7,
+        'solar': 1890.8,
+        'unknown': 0.0,
+        'wind': 44.2,
+      }),
+      'source': 'ceps.cz',
+      'sourceType': <EventSourceType.measured: 'measured'>,
+      'storage': dict({
+        'hydro': 487.666,
+      }),
+      'zoneKey': 'CZ',
+    }),
+  ])
+# ---
diff --git a/electricitymap/contrib/parsers/tests/mocks/CZ/Generation.xml b/electricitymap/contrib/parsers/tests/mocks/CZ/Generation.xml
new file mode 100644
index 0000000000..44e37a8c9f
--- /dev/null
+++ b/electricitymap/contrib/parsers/tests/mocks/CZ/Generation.xml
@@ -0,0 +1 @@
+<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><GenerationResponse xmlns="https://www.ceps.cz/CepsData/"><GenerationResult><root xmlns="https://www.ceps.cz/CepsData/StructuredData/1.0"><information><name>Generation</name><date_from>2026-07-01T06:00:00+02:00</date_from><date_to>2026-07-01T12:00:00+02:00</date_to><version>RT</version><function>AVG</function><aggregation>QH</aggregation><typeofgeneratingplant>all</typeofgeneratingplant></information><series><serie id="value1" name="TPP [MW]" /><serie id="value2" name="CCGT [MW]" /><serie id="value3" name="NPP [MW]" /><serie id="value4" name="HPP [MW]" /><serie id="value5" name="PsPP [MW]" /><serie id="value6" name="AltPP [MW]" /><serie id="value7" name="ApPP [MW]" /><serie id="value8" name="WPP [MW]" /><serie id="value9" name="PVPP [MW]" /></series><data><item date="2026-07-01T06:00:00+02:00" value1="3633.2" value2="1015.9" value3="4128" value4="55.5" value5="0" value6="138.1" value7="0" value8="35.1" value9="153.4" /><item date="2026-07-01T06:15:00+02:00" value1="3637.7" value2="1026.6" value3="4129.8" value4="55.9" value5="0" value6="139" value7="0" value8="31.5" value9="220.5" /><item date="2026-07-01T06:30:00+02:00" value1="3637.3" value2="1043.5" value3="4129" value4="55.9" value5="162.5" value6="138.2" value7="0" value8="27.2" value9="276.4" /><item date="2026-07-01T06:45:00+02:00" value1="3643.3" value2="1046.9" value3="4128.5" value4="55.9" value5="162.5" value6="137.8" value7="0" value8="21.8" value9="347.3" /><item date="2026-07-01T07:00:00+02:00" value1="3639.8" value2="1050.9" value3="4127.3" value4="78" value5="160.1" value6="137.5" value7="0" value8="26.8" value9="421" /><item date="2026-07-01T07:15:00+02:00" value1="3641.1" value2="1052.2" value3="4127.7" value4="81.3" value5="166.4" value6="136.1" value7="0" value8="26.1" value9="537.9" /><item date="2026-07-01T07:30:00+02:00" value1="3651.9" value2="1052.2" value3="4128.6" value4="81.3" value5="0" value6="136.1" value7="0" value8="32.3" value9="643.9" /><item date="2026-07-01T07:45:00+02:00" value1="3656.7" value2="1047.4" value3="4129.6" value4="80.2" value5="0" value6="136.4" value7="0" value8="30.5" value9="746.2" /><item date="2026-07-01T08:00:00+02:00" value1="3621" value2="1021.2" value3="4131.1" value4="66.7" value5="0" value6="136.5" value7="0" value8="31.6" value9="811.3" /><item date="2026-07-01T08:15:00+02:00" value1="3614" value2="1024.4" value3="4127.9" value4="66.5" value5="0" value6="136.8" value7="0" value8="39.2" value9="914.4" /><item date="2026-07-01T08:30:00+02:00" value1="3651.8" value2="1018.4" value3="4124.9" value4="66.5" value5="0" value6="136.4" value7="0" value8="39.7" value9="982.6" /><item date="2026-07-01T08:45:00+02:00" value1="3684.8" value2="1016.3" value3="4121.4" value4="64.8" value5="0" value6="136.5" value7="0" value8="27.6" value9="1056" /><item date="2026-07-01T09:00:00+02:00" value1="3658.1" value2="1008.6" value3="4118.7" value4="44.2" value5="0" value6="135.6" value7="0" value8="25.3" value9="1148.7" /><item date="2026-07-01T09:15:00+02:00" value1="3649.9" value2="980.3" value3="4114.5" value4="43.7" value5="0" value6="136.4" value7="0" value8="27.7" value9="1176.8" /><item date="2026-07-01T09:30:00+02:00" value1="3660.9" value2="889.4" value3="4111.9" value4="43.7" value5="0" value6="136.8" value7="0" value8="39.8" value9="1243" /><item date="2026-07-01T09:45:00+02:00" value1="3663.4" value2="823.4" value3="4110.1" value4="43.7" value5="0" value6="137.4" value7="0" value8="38" value9="1319.5" /><item date="2026-07-01T10:00:00+02:00" value1="3671.2" value2="820.4" value3="4107.8" value4="43.7" value5="0" value6="137" value7="0" value8="33" value9="1408.9" /><item date="2026-07-01T10:15:00+02:00" value1="3667.5" value2="821.2" value3="4107.2" value4="43.7" value5="0" value6="137.3" value7="0" value8="27" value9="1500.9" /><item date="2026-07-01T10:30:00+02:00" value1="3668.6" value2="826.3" value3="4106.1" value4="43.7" value5="0" value6="137.7" value7="0" value8="26.2" value9="1587.7" /><item date="2026-07-01T10:45:00+02:00" value1="3657.7" value2="811.5" value3="4103.4" value4="43.7" value5="0" value6="138.3" value7="0" value8="26" value9="1686.6" /><item date="2026-07-01T11:00:00+02:00" value1="3658.8" value2="825.3" value3="4102.2" value4="43.7" value5="0" value6="138.8" value7="0" value8="27.8" value9="1723.9" /><item date="2026-07-01T11:15:00+02:00" value1="3654.7" value2="825.3" value3="4102.2" value4="43.7" value5="0" value6="138.6" value7="0" value8="35.1" value9="1774.9" /><item date="2026-07-01T11:30:00+02:00" value1="3645.4" value2="805.4" value3="4102.7" value4="43.7" value5="0" value6="138.7" value7="0" value8="38.8" value9="1874.2" /><item date="2026-07-01T11:45:00+02:00" value1="3643.8" value2="799.7" value3="4103.1" value4="43.7" value5="0" value6="138.6" value7="0" value8="40.7" value9="1880.3" /><item date="2026-07-01T12:00:00+02:00" value1="3603.2" value2="798" value3="4104.7" value4="43.7" value5="0" value6="137.9" value7="0" value8="44.2" value9="1890.8" /></data></root></GenerationResult></GenerationResponse></soap:Body></soap:Envelope>
\ No newline at end of file
diff --git a/electricitymap/contrib/parsers/tests/mocks/CZ/Load.xml b/electricitymap/contrib/parsers/tests/mocks/CZ/Load.xml
new file mode 100644
index 0000000000..ac9a520422
--- /dev/null
+++ b/electricitymap/contrib/parsers/tests/mocks/CZ/Load.xml
@@ -0,0 +1 @@
+<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><LoadResponse xmlns="https://www.ceps.cz/CepsData/"><LoadResult><root xmlns="https://www.ceps.cz/CepsData/StructuredData/1.0"><information><name>Load</name><date_from>2026-07-01T06:00:00+02:00</date_from><date_to>2026-07-01T12:00:00+02:00</date_to><version>RT</version><function>AVG</function><aggregation>QH</aggregation></information><series><serie id="value1" name="Load including pumping [MW]" /><serie id="value2" name="Load [MW]" /></series><data><item date="2026-07-01T06:00:00+02:00" value1="7089" value2="7089" /><item date="2026-07-01T06:15:00+02:00" value1="7375.2" value2="7375.2" /><item date="2026-07-01T06:30:00+02:00" value1="7586.733" value2="7586.733" /><item date="2026-07-01T06:45:00+02:00" value1="7728.733" value2="7728.733" /><item date="2026-07-01T07:00:00+02:00" value1="7894.6" value2="7894.6" /><item date="2026-07-01T07:15:00+02:00" value1="8021.867" value2="8021.867" /><item date="2026-07-01T07:30:00+02:00" value1="8157.2" value2="8157.2" /><item date="2026-07-01T07:45:00+02:00" value1="8270.134" value2="8270.134" /><item date="2026-07-01T08:00:00+02:00" value1="8327.6" value2="8327.6" /><item date="2026-07-01T08:15:00+02:00" value1="8502.267" value2="8502.267" /><item date="2026-07-01T08:30:00+02:00" value1="8648.267" value2="8648.267" /><item date="2026-07-01T08:45:00+02:00" value1="8727.934" value2="8727.934" /><item date="2026-07-01T09:00:00+02:00" value1="8802.267" value2="8802.267" /><item date="2026-07-01T09:15:00+02:00" value1="8834.8" value2="8834.8" /><item date="2026-07-01T09:30:00+02:00" value1="8924" value2="8924" /><item date="2026-07-01T09:45:00+02:00" value1="8946.8" value2="8946.8" /><item date="2026-07-01T10:00:00+02:00" value1="8937.333" value2="8937.333" /><item date="2026-07-01T10:15:00+02:00" value1="8949.934" value2="8949.934" /><item date="2026-07-01T10:30:00+02:00" value1="8987.733" value2="8987.733" /><item date="2026-07-01T10:45:00+02:00" value1="9330.533" value2="9329.134" /><item date="2026-07-01T11:00:00+02:00" value1="9488.733" value2="9383.934" /><item date="2026-07-01T11:15:00+02:00" value1="9612.533" value2="9507.333" /><item date="2026-07-01T11:30:00+02:00" value1="9762.134" value2="9607.267" /><item date="2026-07-01T11:45:00+02:00" value1="9788.866" value2="9314.134" /><item date="2026-07-01T12:00:00+02:00" value1="9777.6" value2="9289.934" /></data></root></LoadResult></LoadResponse></soap:Body></soap:Envelope>
\ No newline at end of file
diff --git a/electricitymap/contrib/parsers/tests/test_CZ.py b/electricitymap/contrib/parsers/tests/test_CZ.py
index eb4fc059df..07e48dec4a 100644
--- a/electricitymap/contrib/parsers/tests/test_CZ.py
+++ b/electricitymap/contrib/parsers/tests/test_CZ.py
@@ -1,4 +1,5 @@
 from datetime import datetime
+from logging import getLogger
 from pathlib import Path
 
 import pytest
@@ -14,6 +15,17 @@
 # Using a fixed date that exists in the mock XML data
 TARGET_DATETIME = datetime(2025, 10, 31, 18, 0, 0)
 
+# Fixed date matching the Generation.xml and Load.xml mocks
+PRODUCTION_TARGET_DATETIME = datetime(2026, 7, 1, 12, 0, 0)
+
+
+def _is_generation_request(request) -> bool:
+    return "<Generation" in request.text
+
+
+def _is_load_request(request) -> bool:
+    return "<Load" in request.text
+
 
 @pytest.fixture
 def mock_good_response(requests_mock):
@@ -84,3 +96,182 @@ def test_fetch_exchange_raises_exception_on_no_data(session, mock_no_data_respon
             session=session,
             target_datetime=TARGET_DATETIME,
         )
+
+
+@pytest.fixture
+def mock_production_response(requests_mock):
+    """
+    Mocks the CEPS API for fetch_production. Generation and Load POST to the
+    same endpoint, so the two responses are matched on the SOAP body.
+    """
+
+    requests_mock.register_uri(
+        POST,
+        CZ.url,
+        additional_matcher=_is_generation_request,
+        content=(base_path_to_mock / "Generation.xml").read_bytes(),
+    )
+    requests_mock.register_uri(
+        POST,
+        CZ.url,
+        additional_matcher=_is_load_request,
+        content=(base_path_to_mock / "Load.xml").read_bytes(),
+    )
+
+
+@pytest.fixture
+def mock_production_response_without_load_data(requests_mock):
+    """
+    Mocks the CEPS API with a valid Generation response but a Load response
+    that is missing the <data> tag.
+    """
+
+    requests_mock.register_uri(
+        POST,
+        CZ.url,
+        additional_matcher=_is_generation_request,
+        content=(base_path_to_mock / "Generation.xml").read_bytes(),
+    )
+    mock_load_content = (
+        '<root xmlns="https://www.ceps.cz/CepsData/StructuredData/1.0">'
+        "<information><name>Load</name></information>"
+        '<series><serie id="value1" name="Load including pumping [MW]" />'
+        '<serie id="value2" name="Load [MW]" /></series>'
+        "</root>"
+    )
+    requests_mock.register_uri(
+        POST,
+        CZ.url,
+        additional_matcher=_is_load_request,
+        text=mock_load_content,
+    )
+
+
+def test_fetch_production(session, snapshot, mock_production_response):
+    result = CZ.fetch_production(
+        zone_key=ZoneKey("CZ"),
+        session=session,
+        target_datetime=PRODUCTION_TARGET_DATETIME,
+    )
+
+    assert snapshot(extension_class=SingleFileAmberSnapshotExtension) == result
+
+
+def test_fetch_production_storage(session, mock_production_response):
+    result = CZ.fetch_production(
+        zone_key=ZoneKey("CZ"),
+        session=session,
+        target_datetime=PRODUCTION_TARGET_DATETIME,
+    )
+
+    by_datetime = {event["datetime"].isoformat(): event for event in result}
+
+    # 06:30: pumped storage generating 162.5 MW, no pumping (both Load series equal)
+    discharging = by_datetime["2026-07-01T06:30:00+02:00"]
+    assert discharging["storage"]["hydro"] == -162.5
+
+    # 12:00: no pumped storage generation, pumping 9777.6 - 9289.934 MW
+    pumping = by_datetime["2026-07-01T12:00:00+02:00"]
+    assert pumping["storage"]["hydro"] == pytest.approx(487.666)
+
+
+def test_fetch_production_without_load_data(
+    session, mock_production_response_without_load_data
+):
+    result = CZ.fetch_production(
+        zone_key=ZoneKey("CZ"),
+        session=session,
+        target_datetime=PRODUCTION_TARGET_DATETIME,
+    )
+
+    # production events are still returned, with storage from generation only
+    assert len(result) == 25
+    assert result[2]["storage"]["hydro"] == -162.5
+
+
+def test_fetch_production_with_load_error(session, requests_mock):
+    requests_mock.register_uri(
+        POST,
+        CZ.url,
+        additional_matcher=_is_generation_request,
+        content=(base_path_to_mock / "Generation.xml").read_bytes(),
+    )
+    requests_mock.register_uri(
+        POST,
+        CZ.url,
+        additional_matcher=_is_load_request,
+        status_code=500,
+    )
+
+    result = CZ.fetch_production(
+        zone_key=ZoneKey("CZ"),
+        session=session,
+        target_datetime=PRODUCTION_TARGET_DATETIME,
+    )
+
+    # a failing Load request only costs the pumping enrichment
+    assert len(result) == 25
+    assert result[2]["storage"]["hydro"] == -162.5
+
+
+def test_fetch_production_raises_exception_on_no_data(session, requests_mock):
+    mock_xml_content = (
+        '<root xmlns="https://www.ceps.cz/CepsData/StructuredData/1.0">'
+        "<information><name>Generation</name></information>"
+        '<series><serie id="value1" name="TPP [MW]" /></series>'
+        "</root>"
+    )
+    requests_mock.register_uri(POST, CZ.url, text=mock_xml_content)
+
+    with pytest.raises(ParserException):
+        CZ.fetch_production(
+            zone_key=ZoneKey("CZ"),
+            session=session,
+            target_datetime=PRODUCTION_TARGET_DATETIME,
+        )
+
+
+def test_get_pumping_clamps_negative_diff(session, requests_mock):
+    mock_load_content = (
+        '<root xmlns="https://www.ceps.cz/CepsData/StructuredData/1.0">'
+        "<information><name>Load</name></information>"
+        '<series><serie id="value1" name="Load including pumping [MW]" />'
+        '<serie id="value2" name="Load [MW]" /></series>'
+        '<data><item date="2026-07-01T06:00:00+02:00" value1="7000" value2="7000.4" />'
+        '<item date="2026-07-01T06:15:00+02:00" value1="7500" value2="7100" /></data>'
+        "</root>"
+    )
+    requests_mock.register_uri(POST, CZ.url, text=mock_load_content)
+
+    result = CZ.get_pumping_by_datetime(
+        session=session,
+        date_from=datetime(2026, 7, 1, 6, 0, 0),
+        date_to=datetime(2026, 7, 1, 6, 15, 0),
+        zone_key=ZoneKey("CZ"),
+        logger=getLogger(__name__),
+    )
+
+    # negative rounding artifacts clamp to zero instead of reading as discharge
+    assert result[datetime.fromisoformat("2026-07-01T06:00:00+02:00")] == 0.0
+    assert result[datetime.fromisoformat("2026-07-01T06:15:00+02:00")] == 400.0
+
+
+def test_get_pumping_returns_empty_on_missing_series(session, requests_mock):
+    mock_load_content = (
+        '<root xmlns="https://www.ceps.cz/CepsData/StructuredData/1.0">'
+        "<information><name>Load</name></information>"
+        '<series><serie id="value1" name="Load [MW]" /></series>'
+        '<data><item date="2026-07-01T06:00:00+02:00" value1="7000" /></data>'
+        "</root>"
+    )
+    requests_mock.register_uri(POST, CZ.url, text=mock_load_content)
+
+    result = CZ.get_pumping_by_datetime(
+        session=session,
+        date_from=datetime(2026, 7, 1, 6, 0, 0),
+        date_to=datetime(2026, 7, 1, 6, 15, 0),
+        zone_key=ZoneKey("CZ"),
+        logger=getLogger(__name__),
+    )
+
+    assert result == {}