feat(battery): forced discharge to grid mode (feed-in arbitrage)

api/batterymode.go

@@ -1,6 +1,6 @@
 package api
 
-// BatteryMode is the home battery operation mode. Valid values are normal, hold, charge and holdcharge
+// BatteryMode is the home battery operation mode. Valid values are normal, hold, charge, holdcharge and discharge
 type BatteryMode int
 
 //go:generate go tool enumer -type BatteryMode -trimprefix Battery -transform=lower
@@ -10,4 +10,5 @@ const (
 	BatteryHold
 	BatteryCharge
 	BatteryHoldCharge
+	BatteryDischarge // forced discharge to grid (feed-in arbitrage)
 )

assets/js/components/Battery/BatteryExperimental.vue

@@ -32,6 +32,15 @@
 		>
 			<SmartCostLimit v-bind="smartCostLimitProps" />
 		</Card>
+
+		<Card
+			v-if="gridDischargeVisible"
+			class="box-pull-out mt-4"
+			:title="$t('batterySettings.gridDischargeTab')"
+			data-testid="battery-grid-discharge-limit"
+		>
+			<SmartFeedInPriority v-bind="smartFeedInPriorityProps" />
+		</Card>
 	</div>
 	<p v-else class="my-4 text-muted">{{ $t("batterySettings.noBattery") }}</p>
 </template>
@@ -44,6 +53,7 @@ import api from "@/api";
 import { SMART_COST_TYPE, CURRENCY, type BatteryMeter } from "@/types/evcc";
 import Card from "../Helper/Card.vue";
 import SmartCostLimit from "../Tariff/SmartCostLimit.vue";
+import SmartFeedInPriority from "../Tariff/SmartFeedInPriority.vue";
 import BatteryStatusCards from "./BatteryStatusCards.vue";
 import BatteryConfigCard from "./BatteryConfigCard.vue";
 import BatteryHistoryCard from "./BatteryHistoryCard.vue";
@@ -57,6 +67,7 @@ export default defineComponent({
 	components: {
 		Card,
 		SmartCostLimit,
+		SmartFeedInPriority,
 		BatteryStatusCards,
 		BatteryConfigCard,
 		BatteryHistoryCard,
@@ -130,6 +141,33 @@ export default defineComponent({
 				possible: this.gridChargePossible,
 			};
 		},
+		gridDischargeLimit(): number | null {
+			return this.state.batteryGridDischargeLimit ?? null;
+		},
+		// needs a dynamic feed-in tariff, the grid price is irrelevant here
+		gridDischargePossible(): boolean {
+			return (
+				this.devices.some(({ controllable }) => controllable) &&
+				!!this.state.smartFeedInPriorityAvailable
+			);
+		},
+		// the limit is inert unless the experimental grid discharge setting is on. a
+		// limit that is already set stays reachable so it can be removed
+		gridDischargeVisible(): boolean {
+			return (
+				!!this.state.batteryGridDischarge &&
+				(this.gridDischargePossible || this.gridDischargeLimit !== null)
+			);
+		},
+		smartFeedInPriorityProps() {
+			return {
+				currentLimit: this.gridDischargeLimit,
+				lastLimit: settings.lastBatteryGridDischargeLimit,
+				currency: this.state.currency || CURRENCY.EUR,
+				tariff: store.uiForecast.value.feedin,
+				possible: this.gridDischargePossible,
+			};
+		},
 	},
 	watch: {
 		// fetchHistory reloads only when the needed range is not already covered

assets/js/components/Loadpoints/SettingsModal.vue

@@ -26,6 +26,7 @@
 				:last-limit="loadpoint?.lastSmartFeedInPriorityLimit"
 				:currency="currency"
 				:loadpoint-id="id"
+				is-loadpoint
 				:multiple-loadpoints="multipleLoadpoints"
 				:possible="smartFeedInPriorityAvailable"
 				:tariff="forecast?.feedin"

assets/js/components/Tariff/SmartFeedInPriority.vue

@@ -4,7 +4,7 @@
 		:current-limit="currentLimit"
 		:last-limit="lastLimit"
 		:currency="currency"
-		:apply-all="multipleLoadpoints"
+		:apply-all="isLoadpoint && multipleLoadpoints"
 		:possible="possible"
 		:tariff="tariff"
 		:form-id="formId"
@@ -23,6 +23,7 @@
 import { defineComponent, type PropType } from "vue";
 import SmartTariffBase from "./SmartTariffBase.vue";
 import api from "@/api";
+import settings from "@/settings";
 import { type CURRENCY } from "@/types/evcc";
 import { setLoadpointLastSmartFeedInPriorityLimit } from "@/uiLoadpoints";
 
@@ -37,19 +38,20 @@ export default defineComponent({
 		lastLimit: Number,
 		currency: String as PropType<CURRENCY>,
 		loadpointId: String,
+		isLoadpoint: Boolean,
 		multipleLoadpoints: Boolean,
 		possible: Boolean,
 		tariff: Array,
 	},
 	computed: {
 		formId(): string {
-			return `smartFeedInPriority-${this.loadpointId}`;
+			return `smartFeedInPriority-${this.loadpointId || "battery"}`;
 		},
 		labels() {
 			const t = (key: string) => this.$t(`smartFeedInPriority.${key}`);
 			return {
-				title: t("title"),
-				description: t("description"),
+				title: this.isLoadpoint ? t("title") : "",
+				description: this.isLoadpoint ? t("description") : t("batteryDescription"),
 				limitLabel: t("priceLimit"),
 				activeHoursLabel: t("activeHoursLabel"),
 				currentPriceLabel: t("priceLabel"),
@@ -71,19 +73,27 @@ export default defineComponent({
 
 			if (!active) return;
 
-			const url = `loadpoints/${this.loadpointId}/smartfeedinprioritylimit`;
+			const url = this.isLoadpoint
+				? `loadpoints/${this.loadpointId}/smartfeedinprioritylimit`
+				: "batterygriddischargelimit";
+
 			await api.post(`${url}/${encodeURIComponent(limit)}`);
 		},
 		saveLastLimit(limit: number) {
-			if (this.loadpointId) {
-				setLoadpointLastSmartFeedInPriorityLimit(this.loadpointId, limit);
+			if (this.isLoadpoint) {
+				setLoadpointLastSmartFeedInPriorityLimit(this.loadpointId!, limit);
+			} else {
+				settings.lastBatteryGridDischargeLimit = limit;
 			}
 		},
 		async deleteLimit() {
 			// save last selected value to be suggest again when reactivating limit
 			this.saveLastLimit(this.currentLimit || 0);
 
-			const url = `loadpoints/${this.loadpointId}/smartfeedinprioritylimit`;
+			const url = this.isLoadpoint
+				? `loadpoints/${this.loadpointId}/smartfeedinprioritylimit`
+				: "batterygriddischargelimit";
+
 			await api.delete(url);
 		},
 		async applyToAll(selectedLimit: number | null) {

assets/js/settings.ts

@@ -23,6 +23,7 @@ const BATTERY_UNIT = "battery_unit";
 const SETTINGS_PRICE_ZOOM = "settings_price_zoom";
 const SETTINGS_HIDE_FEEDIN = "settings_hide_feedin";
 const LAST_BATTERY_SMART_COST_LIMIT = "last_battery_smart_cost_limit";
+const LAST_BATTERY_GRID_DISCHARGE_LIMIT = "last_battery_grid_discharge_limit";
 const LAST_TARGET_TIME = "last_target_time";
 const LAST_SOC_GOAL = "last_soc_goal";
 const LAST_ENERGY_GOAL = "last_energy_goal";
@@ -129,6 +130,7 @@ export interface Settings {
   hideFeedin: boolean;
   loadpoints: Record<string, LoadpointSettings>;
   lastBatterySmartCostLimit: number | undefined;
+  lastBatteryGridDischargeLimit: number | undefined;
   lastTargetTime: string | null;
   lastSocGoal: number | undefined;
   lastEnergyGoal: number | undefined;
@@ -158,6 +160,7 @@ const settings: Settings = reactive({
   hideFeedin: readBool(SETTINGS_HIDE_FEEDIN),
   loadpoints: readJSON(LOADPOINTS),
   lastBatterySmartCostLimit: readNumber(LAST_BATTERY_SMART_COST_LIMIT),
+  lastBatteryGridDischargeLimit: readNumber(LAST_BATTERY_GRID_DISCHARGE_LIMIT),
   lastTargetTime: read(LAST_TARGET_TIME),
   lastSocGoal: readNumber(LAST_SOC_GOAL),
   lastEnergyGoal: readNumber(LAST_ENERGY_GOAL),
@@ -186,6 +189,7 @@ watch(() => settings.priceZoom, saveBool(SETTINGS_PRICE_ZOOM));
 watch(() => settings.hideFeedin, saveBool(SETTINGS_HIDE_FEEDIN));
 watch(() => settings.loadpoints, saveJSON(LOADPOINTS), { deep: true });
 watch(() => settings.lastBatterySmartCostLimit, saveNumber(LAST_BATTERY_SMART_COST_LIMIT));
+watch(() => settings.lastBatteryGridDischargeLimit, saveNumber(LAST_BATTERY_GRID_DISCHARGE_LIMIT));
 watch(() => settings.lastTargetTime, save(LAST_TARGET_TIME));
 watch(() => settings.lastSocGoal, saveNumber(LAST_SOC_GOAL));
 watch(() => settings.lastEnergyGoal, saveNumber(LAST_ENERGY_GOAL));

assets/js/types/evcc.ts

@@ -282,6 +282,10 @@ export interface State {
   batteryGridChargeLimit?: number | null;
   /** Home battery is currently charged from grid. */
   batteryGridChargeActive?: boolean;
+  /** Feed-in price limit for discharging the home battery to the grid (experimental). */
+  batteryGridDischargeLimit?: number | null;
+  /** Home battery is currently discharged to the grid. */
+  batteryGridDischargeActive?: boolean;
   /** A dynamic grid price or CO₂ forecast is configured. */
   smartCostAvailable?: boolean;
   /** Type of the smart charging limit, price based or emission based. */
@@ -830,6 +834,7 @@ export enum BATTERY_MODE {
   HOLD = "hold",
   CHARGE = "charge",
   HOLDCHARGE = "holdcharge",
+  DISCHARGE = "discharge",
 }
 
 export enum PHASES {

cmd/flags.go

@@ -47,7 +47,7 @@ const (
 	flagCustomPhoneDescription = "Support phone number shown in the UI"
 
 	flagBatteryMode                = "battery-mode"
-	flagBatteryModeDescription     = "Set battery mode (normal, hold, charge, holdcharge)"
+	flagBatteryModeDescription     = "Set battery mode (normal, hold, charge, holdcharge, discharge)"
 	flagBatteryModeWait            = "battery-mode-wait"
 	flagBatteryModeWaitDescription = "Wait given duration during which potential watchdogs are active"
 

core/keys/site.go

@@ -42,12 +42,14 @@ const (
 	ConsumerMeters = "consumerMeters"
 
 	// battery settings
-	BatteryDischargeControl = "batteryDischargeControl"
-	BatteryGridChargeLimit  = "batteryGridChargeLimit"
-	BatteryGridChargeActive = "batteryGridChargeActive"
-	BatteryGridDischarge    = "batteryGridDischarge"
-	BufferSoc               = "bufferSoc"
-	BufferStartSoc          = "bufferStartSoc"
+	BatteryDischargeControl    = "batteryDischargeControl"
+	BatteryGridChargeLimit     = "batteryGridChargeLimit"
+	BatteryGridChargeActive    = "batteryGridChargeActive"
+	BatteryGridDischargeLimit  = "batteryGridDischargeLimit"
+	BatteryGridDischargeActive = "batteryGridDischargeActive"
+	BatteryGridDischarge       = "batteryGridDischarge"
+	BufferSoc                  = "bufferSoc"
+	BufferStartSoc             = "bufferStartSoc"
 
 	// grid settings
 	GridExportLimit = "gridExportLimit"

core/site.go

@@ -80,12 +80,13 @@ type Site struct {
 	curtailPercent *int
 
 	// battery settings
-	prioritySoc             float64  // prefer battery up to this Soc
-	bufferSoc               float64  // continue charging on battery above this Soc
-	bufferStartSoc          float64  // start charging on battery above this Soc
-	batteryDischargeControl bool     // prevent battery discharge for fast and planned charging
-	batteryGridChargeLimit  *float64 // grid charging limit
-	batteryGridDischarge    bool     // allow battery discharge to grid (experimental)
+	prioritySoc               float64  // prefer battery up to this Soc
+	bufferSoc                 float64  // continue charging on battery above this Soc
+	bufferStartSoc            float64  // start charging on battery above this Soc
+	batteryDischargeControl   bool     // prevent battery discharge for fast and planned charging
+	batteryGridChargeLimit    *float64 // grid charging limit
+	batteryGridDischargeLimit *float64 // grid discharging (feed-in) limit
+	batteryGridDischarge      bool     // allow battery discharge to grid (experimental)
 
 	// grid settings
 	gridExportLimit float64 // static grid export power limit in W, 0 = disabled
@@ -406,6 +407,11 @@ func (site *Site) restoreSettings() error {
 			return err
 		}
 	}
+	if v, err := settings.Float(keys.BatteryGridDischargeLimit); err == nil {
+		if err := site.SetBatteryGridDischargeLimit(&v); err != nil && !errors.Is(err, ErrBatteryControlNotAvailable) {
+			return err
+		}
+	}
 	if v, err := settings.Bool(keys.SolarAdjusted); err == nil {
 		site.SetSolarAdjusted(v)
 	}
@@ -1222,7 +1228,16 @@ func (site *Site) update(lp updater) {
 	// update battery after reading meters to ensure that (modbus) connection is open
 	batteryGridChargeActive := site.batteryGridChargeActive(rate)
 	site.publish(keys.BatteryGridChargeActive, batteryGridChargeActive)
-	site.updateBatteryMode(batteryGridChargeActive, rate)
+
+	// grid discharge (feed-in arbitrage) uses the feed-in rate, not the grid rate
+	feedinRate, err := feedin.At(time.Now())
+	if feedin != nil && err != nil {
+		site.log.WARN.Printf("feed-in: no matching rate for: %s", time.Now().Format(time.RFC3339))
+	}
+	batteryGridDischargeActive := site.batteryGridDischargeActive(feedinRate)
+	site.publish(keys.BatteryGridDischargeActive, batteryGridDischargeActive)
+
+	site.updateBatteryMode(batteryGridChargeActive, batteryGridDischargeActive, rate)
 
 	// re-evaluate against the updated loadpoint state
 	site.publishSuggestions()

core/site/api.go

@@ -56,6 +56,10 @@ type API interface {
 	GetBatteryGridChargeLimit() *float64
 	// SetBatteryGridChargeLimit sets the grid charge limit
 	SetBatteryGridChargeLimit(limit *float64) error
+	// GetBatteryGridDischargeLimit get the grid discharge (feed-in) limit
+	GetBatteryGridDischargeLimit() *float64
+	// SetBatteryGridDischargeLimit sets the grid discharge (feed-in) limit
+	SetBatteryGridDischargeLimit(limit *float64) error
 
 	// GetOptimizerChargingStrategy gets the optimizer grid charging strategy
 	GetOptimizerChargingStrategy() string

core/site_api.go

@@ -482,6 +482,37 @@ func (site *Site) SetBatteryGridChargeLimit(val *float64) error {
 	return nil
 }
 
+func (site *Site) GetBatteryGridDischargeLimit() *float64 {
+	site.RLock()
+	defer site.RUnlock()
+	return site.batteryGridDischargeLimit
+}
+
+func (site *Site) SetBatteryGridDischargeLimit(val *float64) error {
+	site.log.DEBUG.Println("set grid discharge limit:", printPtr("%.1f", val))
+
+	if !site.hasBatteryControl() {
+		return ErrBatteryControlNotAvailable
+	}
+
+	site.Lock()
+	defer site.Unlock()
+
+	if !ptrValueEqual(site.batteryGridDischargeLimit, val) {
+		site.batteryGridDischargeLimit = val
+
+		if val == nil {
+			settings.SetString(keys.BatteryGridDischargeLimit, "")
+			site.publish(keys.BatteryGridDischargeLimit, nil)
+		} else {
+			settings.SetFloat(keys.BatteryGridDischargeLimit, *val)
+			site.publish(keys.BatteryGridDischargeLimit, *val)
+		}
+	}
+
+	return nil
+}
+
 // GetOptimizerChargingStrategy returns the optimizer grid charging strategy,
 // falling back to the default when unset.
 func (site *Site) GetOptimizerChargingStrategy() string {