diff --git a/assets/js/components/History/EnergyChart.vue b/assets/js/components/History/EnergyChart.vue
index 59705dc45..60bebe8c7 100644
--- a/assets/js/components/History/EnergyChart.vue
+++ b/assets/js/components/History/EnergyChart.vue
@@ -25,7 +25,7 @@ import { commonOptions } from "../Sessions/chartConfig";
 import LegendList from "../Sessions/LegendList.vue";
 import type { Legend } from "../Sessions/types";
 import formatter from "@/mixins/formatter";
-import type { SeriesData } from "./Chart.vue";
+import type { SeriesData } from "./PowerChart.vue";
 
 ChartJS.register(CategoryScale, LinearScale, BarController, BarElement, Tooltip);
 
@@ -79,7 +79,7 @@ export default defineComponent({
 				const exportData = dayKeys.map((key) => -(byDay[key]?.export ?? 0));
 				const hasExport = exportData.some((v) => v !== 0);
 
-				const importLabel = hasExport ? `${s.name} (import)` : s.name;
+				const importLabel = hasExport ? `${s.group} (import)` : s.group;
 
 				datasets.push({
 					label: importLabel,
@@ -90,7 +90,7 @@ export default defineComponent({
 
 				if (hasExport) {
 					datasets.push({
-						label: `${s.name} (export)`,
+						label: `${s.group} (export)`,
 						data: exportData,
 						backgroundColor: lighterColor(color),
 						stack: `s${i}`,
@@ -153,11 +153,11 @@ export default defineComponent({
 				const color = colors.palette[i % colors.palette.length];
 				const hasExport = s.data.some((slot) => slot.export > 0);
 
-				const importLabel = hasExport ? `${s.name} (import)` : s.name;
+				const importLabel = hasExport ? `${s.group} (import)` : s.group;
 				result.push({ label: importLabel, color, value: "" });
 				if (hasExport) {
 					result.push({
-						label: `${s.name} (export)`,
+						label: `${s.group} (export)`,
 						color: lighterColor(color),
 						value: "",
 					});
diff --git a/assets/js/components/History/Chart.vue b/assets/js/components/History/PowerChart.vue
similarity index 97%
rename from assets/js/components/History/Chart.vue
rename to assets/js/components/History/PowerChart.vue
index 4e71801fc..0767ccf35 100644
--- a/assets/js/components/History/Chart.vue
+++ b/assets/js/components/History/PowerChart.vue
@@ -48,7 +48,8 @@ interface Slot {
 }
 
 export interface SeriesData {
-	name: string;
+	name?: string;
+	group: string;
 	data: Slot[];
 }
 
@@ -58,7 +59,7 @@ function slotPower(slot: Slot, field: "import" | "export"): number {
 }
 
 export default defineComponent({
-	name: "HistoryChart",
+	name: "HistoryPowerChart",
 	components: { Line, LegendList },
 	mixins: [formatter],
 	props: {
@@ -82,7 +83,7 @@ export default defineComponent({
 				});
 
 				return {
-					label: s.name,
+					label: s.group,
 					data: points,
 					borderColor: color,
 					backgroundColor: fill,
@@ -171,7 +172,7 @@ export default defineComponent({
 		},
 		legends(): Legend[] {
 			return this.series.map((s, i) => ({
-				label: s.name,
+				label: s.group,
 				color: colors.palette[i % colors.palette.length],
 				value: "",
 			}));
diff --git a/assets/js/views/History.vue b/assets/js/views/History.vue
index a346f2d97..2be585133 100644
--- a/assets/js/views/History.vue
+++ b/assets/js/views/History.vue
@@ -32,7 +32,7 @@
 <script lang="ts">
 import { defineComponent } from "vue";
 import Header from "../components/Top/Header.vue";
-import PowerChart from "../components/History/Chart.vue";
+import PowerChart from "../components/History/PowerChart.vue";
 import EnergyChart from "../components/History/EnergyChart.vue";
 import api from "../api";
 
@@ -83,6 +83,7 @@ export default defineComponent({
 						params: {
 							from: this.powerFrom.toISOString(),
 							to: this.powerTo.toISOString(),
+							grouped: true,
 						},
 					}),
 					api.get("history/energy", {
@@ -90,6 +91,7 @@ export default defineComponent({
 							from: this.energyFrom.toISOString(),
 							to: this.powerTo.toISOString(),
 							aggregate: "day",
+							grouped: true,
 						},
 					}),
 				]);
diff --git a/core/metrics/db.go b/core/metrics/db.go
index a3dba16e1..b6049651f 100644
--- a/core/metrics/db.go
+++ b/core/metrics/db.go
@@ -35,8 +35,9 @@ type Slot struct {
 
 // Series represents a named series of energy slots
 type Series struct {
-	Name string `json:"name"`
-	Data []Slot `json:"data"`
+	Name  string `json:"name,omitempty"`
+	Group string `json:"group"`
+	Data  []Slot `json:"data"`
 }
 
 var aggregateFormats = map[string]string{
@@ -60,8 +61,8 @@ var aggregateDurations = map[string]func(time.Time) time.Time{
 	"month": func(t time.Time) time.Time { return t.AddDate(0, 1, 0) },
 }
 
-// QueryImportEnergy returns aggregated import energy data from the meters table
-func QueryImportEnergy(from, to time.Time, aggregate string) ([]Series, error) {
+// QueryImportEnergy returns aggregated energy data, per entity or per group.
+func QueryImportEnergy(from, to time.Time, aggregate string, grouped bool) ([]Series, error) {
 	format, ok := aggregateFormats[aggregate]
 	if !ok {
 		return nil, errors.New("invalid aggregate value")
@@ -74,12 +75,25 @@ func QueryImportEnergy(from, to time.Time, aggregate string) ([]Series, error) {
 	to = to.Local()
 	tz := from.Format("-07:00")
 
+	groupCols := `e.name, e."group", bucket`
+	if grouped {
+		groupCols = `e."group", bucket`
+	}
+
+	type row struct {
+		Name   string
+		Group  string
+		Bucket string
+		Import float64
+		Export float64
+	}
+
 	tx := db.Instance.Table("meters m").
-		Select(`e.name AS label, strftime('` + format + `', m.ts, '` + tz + `') AS bucket,
-		COALESCE(SUM(m."import"), 0) AS import, COALESCE(SUM(m.export), 0) AS export`).
+		Select(`e.name, e."group", strftime(?, m.ts, ?) AS bucket,
+			COALESCE(SUM(m."import"), 0) AS import, COALESCE(SUM(m.export), 0) AS export`, format, tz).
 		Joins("JOIN entities e ON m.meter = e.id").
-		Group("label, bucket").
-		Order("label, bucket")
+		Group(groupCols).
+		Order(groupCols)
 
 	if !from.IsZero() {
 		tx = tx.Where("m.ts >= ?", from)
@@ -88,49 +102,33 @@ func QueryImportEnergy(from, to time.Time, aggregate string) ([]Series, error) {
 		tx = tx.Where("m.ts < ?", to)
 	}
 
-	rows, err := tx.Rows()
-	if err != nil {
+	var rows []row
+	if err := tx.Scan(&rows).Error; err != nil {
 		return nil, err
 	}
-	defer rows.Close()
 
-	seriesMap := make(map[string][]Slot)
-	var order []string
-
-	for rows.Next() {
-		var label, bucket string
-		var imp, exp float64
-
-		if err := rows.Scan(&label, &bucket, &imp, &exp); err != nil {
-			return nil, err
-		}
-
-		start, err := time.ParseInLocation(aggregateGoFormats[aggregate], bucket, time.Now().Location())
+	var res []Series
+	for _, r := range rows {
+		start, err := time.ParseInLocation(aggregateGoFormats[aggregate], r.Bucket, time.Now().Location())
 		if err != nil {
 			return nil, err
 		}
 
-		if _, exists := seriesMap[label]; !exists {
-			order = append(order, label)
+		name := r.Name
+		if grouped {
+			name = ""
 		}
 
-		seriesMap[label] = append(seriesMap[label], Slot{
+		if n := len(res); n == 0 || res[n-1].Name != name || res[n-1].Group != r.Group {
+			res = append(res, Series{Name: name, Group: r.Group})
+		}
+
+		s := &res[len(res)-1]
+		s.Data = append(s.Data, Slot{
 			Start:  start,
 			End:    addDuration(start),
-			Import: imp,
-			Export: exp,
-		})
-	}
-
-	if err := rows.Err(); err != nil {
-		return nil, err
-	}
-
-	res := make([]Series, 0, len(order))
-	for _, name := range order {
-		res = append(res, Series{
-			Name: name,
-			Data: seriesMap[name],
+			Import: r.Import,
+			Export: r.Export,
 		})
 	}
 
diff --git a/core/metrics/db_test.go b/core/metrics/db_test.go
index edc8af20b..dcc409a40 100644
--- a/core/metrics/db_test.go
+++ b/core/metrics/db_test.go
@@ -68,7 +68,7 @@ func TestQueryImportEnergyUTCFilter(t *testing.T) {
 	from := base.Add(-time.Hour).UTC()
 	to := base.Add(time.Hour).UTC()
 
-	res, err := QueryImportEnergy(from, to, "15m")
+	res, err := QueryImportEnergy(from, to, "15m", false)
 	require.NoError(t, err)
 	require.Len(t, res, 1)
 	require.Len(t, res[0].Data, 4, "expected all 4 slots, got %d", len(res[0].Data))
@@ -80,6 +80,43 @@ func TestQueryImportEnergyUTCFilter(t *testing.T) {
 	require.InDelta(t, 1+2+3+4, totalExport, 0.001)
 }
 
+func TestQueryImportEnergyGrouped(t *testing.T) {
+	require.NoError(t, db.NewInstance("sqlite", ":memory:"))
+	require.NoError(t, SetupSchema())
+
+	// two entities sharing the same group, different names
+	e1 := entity{Id: 2, Name: "db:12", Group: "grid"}
+	require.NoError(t, db.Instance.Create(&e1).Error)
+	e2 := entity{Id: 3, Name: "db:13", Group: "grid"}
+	require.NoError(t, db.Instance.Create(&e2).Error)
+
+	loc := time.Now().Location()
+	base := time.Date(2026, 4, 15, 16, 0, 0, 0, loc)
+
+	require.NoError(t, persist(e1, base, 1, 0))
+	require.NoError(t, persist(e2, base, 2, 0))
+	require.NoError(t, persist(e1, base.Add(15*time.Minute), 3, 0))
+	require.NoError(t, persist(e2, base.Add(15*time.Minute), 4, 0))
+
+	from := base.Add(-time.Hour).UTC()
+	to := base.Add(time.Hour).UTC()
+
+	// ungrouped: 2 series
+	res, err := QueryImportEnergy(from, to, "15m", false)
+	require.NoError(t, err)
+	require.Len(t, res, 2)
+
+	// grouped: 1 series, values summed per bucket
+	res, err = QueryImportEnergy(from, to, "15m", true)
+	require.NoError(t, err)
+	require.Len(t, res, 1)
+	require.Equal(t, "grid", res[0].Group)
+	require.Empty(t, res[0].Name)
+	require.Len(t, res[0].Data, 2)
+	require.InDelta(t, 1+2, res[0].Data[0].Import, 0.001)
+	require.InDelta(t, 3+4, res[0].Data[1].Import, 0.001)
+}
+
 func TestUpdateProfile(t *testing.T) {
 	clock := clock.NewMock()
 
diff --git a/server/http_history_handler.go b/server/http_history_handler.go
index 174e666e1..415688bba 100644
--- a/server/http_history_handler.go
+++ b/server/http_history_handler.go
@@ -41,7 +41,9 @@ func energyHistoryHandler(w http.ResponseWriter, r *http.Request) {
 		aggregate = "15m"
 	}
 
-	res, err := metrics.QueryImportEnergy(from, to, aggregate)
+	grouped := q.Get("grouped") == "true"
+
+	res, err := metrics.QueryImportEnergy(from, to, aggregate, grouped)
 	if err != nil {
 		jsonError(w, http.StatusInternalServerError, err)
 		return