diff --git a/src/solver/simulation/common-eco-adq.cpp b/src/solver/simulation/common-eco-adq.cpp
index 3c77627546..9d71716272 100644
--- a/src/solver/simulation/common-eco-adq.cpp
+++ b/src/solver/simulation/common-eco-adq.cpp
@@ -22,7 +22,31 @@ static void RecalculDesEchangesMoyens(Data::Study& study,
                                       const std::vector<AvgExchangeResults*>& balance,
                                       int PasDeTempsDebut)
 {
-    for (uint i = 0; i < (uint)problem.NombreDePasDeTemps; i++)
+    const uint linkCount = study.runtime.interconnectionsCount();
+    const uint hourCount = static_cast<uint>(problem.NombreDePasDeTemps);
+
+    // The average NTC only depends on the link and on the hour, not on the time step being filled
+    // in : compute it once per link for the whole week.
+    std::vector<std::vector<double>> avgDirect(linkCount);
+    std::vector<std::vector<double>> avgIndirect(linkCount);
+    for (uint j = 0; j < linkCount; ++j)
+    {
+        const auto* link = study.runtime.areaLink[j];
+        retrieveAverageNTC(study,
+                           link->directCapacities.timeSeries,
+                           link->timeseriesNumbers,
+                           PasDeTempsDebut,
+                           hourCount,
+                           avgDirect[j]);
+        retrieveAverageNTC(study,
+                           link->indirectCapacities.timeSeries,
+                           link->timeseriesNumbers,
+                           PasDeTempsDebut,
+                           hourCount,
+                           avgIndirect[j]);
+    }
+
+    for (uint i = 0; i < hourCount; i++)
     {
         auto& ntcValues = problem.ValeursDeNTC[i];
         uint decalPasDeTemps = PasDeTempsDebut + i;
@@ -43,32 +67,12 @@ static void RecalculDesEchangesMoyens(Data::Study& study,
             }
         }
 
-        std::vector<double> avgDirect;
-        std::vector<double> avgIndirect;
-        for (uint j = 0; j < study.runtime.interconnectionsCount(); ++j)
+        for (uint j = 0; j < linkCount; ++j)
         {
-            auto* link = study.runtime.areaLink[j];
-            int ret = retrieveAverageNTC(study,
-                                         link->directCapacities.timeSeries,
-                                         link->timeseriesNumbers,
-                                         avgDirect);
-
-            ret = retrieveAverageNTC(study,
-                                     link->indirectCapacities.timeSeries,
-                                     link->timeseriesNumbers,
-                                     avgIndirect)
-                  && ret;
-            if (!ret)
-            {
-                ntcValues.ValeurDeNTCOrigineVersExtremite[j] = avgDirect[decalPasDeTemps];
-                ntcValues.ValeurDeNTCExtremiteVersOrigine[j] = avgIndirect[decalPasDeTemps];
-            }
-            else
-            {
-                assert(false && "invalid NTC");
-            }
+            ntcValues.ValeurDeNTCOrigineVersExtremite[j] = avgDirect[j][i];
+            ntcValues.ValeurDeNTCExtremiteVersOrigine[j] = avgIndirect[j][i];
 
-            auto& mtxParamaters = link->parameters;
+            const auto& mtxParamaters = study.runtime.areaLink[j]->parameters;
             ntcValues.ResistanceApparente[j] = mtxParamaters[Data::fhlImpedances][decalPasDeTemps];
         }
     }
@@ -394,49 +398,50 @@ void BuildThermalPartOfWeeklyProblem(Data::Study& study,
     }
 }
 
-int retrieveAverageNTC(const Data::Study& study,
-                       const Matrix<>& capacities,
-                       const Data::TimeSeriesNumbers& tsNumbers,
-                       std::vector<double>& avg)
+void retrieveAverageNTC(const Data::Study& study,
+                        const Matrix<>& capacities,
+                        const Data::TimeSeriesNumbers& tsNumbers,
+                        uint firstHour,
+                        uint hourCount,
+                        std::vector<double>& avg)
 {
     const auto& parameters = study.parameters;
 
     const auto& yearsWeight = parameters.getYearsWeight();
-    const auto& yearsWeightSum = parameters.getYearsWeightSum();
+    const auto yearsWeightSum = parameters.getYearsWeightSum();
     const auto& yearsFilter = parameters.yearsFilter;
-    const auto width = capacities.width;
-    avg.assign(HOURS_PER_YEAR, 0);
+    const bool singleTS = (capacities.width == 1);
+
+    avg.assign(hourCount, 0.);
 
     std::map<uint32_t, double> weightOfTS;
 
-    for (uint y = 0; y < study.parameters.nbYears; y++)
+    for (uint y = 0; y < parameters.nbYears; y++)
     {
         if (!yearsFilter[y])
         {
             continue;
         }
 
-        uint32_t tsIndex = (width == 1) ? 0 : tsNumbers[y];
+        uint32_t tsIndex = singleTS ? 0 : tsNumbers[y];
         weightOfTS[tsIndex] += yearsWeight[y];
     }
 
     // No need for the year number, only the TS index is required
-    for (const auto& it: weightOfTS)
+    for (const auto& [tsIndex, weight]: weightOfTS)
     {
-        const uint32_t tsIndex = it.first;
-        const double weight = it.second;
+        const auto* column = capacities[tsIndex];
 
-        for (uint h = 0; h < HOURS_PER_YEAR; h++)
+        for (uint h = 0; h < hourCount; h++)
         {
-            avg[h] += capacities[tsIndex][h] * weight;
+            avg[h] += column[firstHour + h] * weight;
         }
     }
 
-    for (uint h = 0; h < HOURS_PER_YEAR; h++)
+    for (auto& value: avg)
     {
-        avg[h] /= yearsWeightSum;
+        value /= yearsWeightSum;
     }
-    return 0;
 }
 
 void finalizeOptimizationStatistics(PROBLEME_HEBDO& problem,
diff --git a/src/solver/simulation/include/antares/solver/simulation/common-eco-adq.h b/src/solver/simulation/include/antares/solver/simulation/common-eco-adq.h
index e04193ce2a..0135c49db8 100644
--- a/src/solver/simulation/include/antares/solver/simulation/common-eco-adq.h
+++ b/src/solver/simulation/include/antares/solver/simulation/common-eco-adq.h
@@ -100,17 +100,21 @@ void interpolateWaterValue(const Data::AreaList& areas,
 void updatingWeeklyFinalHydroLevel(const Data::AreaList& areas, PROBLEME_HEBDO& problem);
 
 /*
-** \brief Compute the weighted average NTC for a link
+** \brief Compute the MC-years weighted average NTC of a link, over a range of hours
 **
-** \param areas : the areas of study
-** \param link The link
-** \param Weighted average NTC for the direct direction
-** \param Weighted average NTC for the indirect direction
+** \param study The study
+** \param capacities NTC time series of the link, for one direction
+** \param tsNumbers TS numbers of the link
+** \param firstHour First hour of the range, in [0, HOURS_PER_YEAR[
+** \param hourCount Number of hours of the range
+** \param avg Weighted average NTC, resized to hourCount. avg[h] refers to hour firstHour + h
 */
-int retrieveAverageNTC(const Data::Study& study,
-                       const Matrix<>& capacities,
-                       const Data::TimeSeriesNumbers& tsNumbers,
-                       std::vector<double>& avg);
+void retrieveAverageNTC(const Data::Study& study,
+                        const Matrix<>& capacities,
+                        const Data::TimeSeriesNumbers& tsNumbers,
+                        uint firstHour,
+                        uint hourCount,
+                        std::vector<double>& avg);
 
 void finalizeOptimizationStatistics(PROBLEME_HEBDO& problem,
                                     Antares::Solver::Variable::State& state);