Meter (SunSpec): read max AC power from nameplate (#32732)

meter/meter.go

@@ -24,7 +24,7 @@ func NewConfigurableFromConfig(ctx context.Context, other map[string]any) (api.M
 		measurement.Curtailer `mapstructure:",squash"` // optional
 
 		// pv
-		pvMaxACPower `mapstructure:",squash"`
+		pvMaxACPowerCtx `mapstructure:",squash"`
 
 		// battery
 		batteryCapacityCtx    `mapstructure:",squash"`
@@ -127,7 +127,7 @@ func NewConfigurableFromConfig(ctx context.Context, other map[string]any) (api.M
 	implement.May(m, implement.PhaseCurrents(currentsG))
 	implement.May(m, implement.PhaseVoltages(voltagesG))
 	implement.May(m, implement.PhasePowers(powersG))
-	implement.May(m, implement.MaxACPowerGetter(cc.pvMaxACPower.Decorator()))
+	implement.May(m, implement.MaxACPowerGetter(cc.pvMaxACPowerCtx.Decorator(ctx)))
 
 	return m, nil
 }

meter/meter_test.go

@@ -22,6 +22,27 @@ func TestPV(t *testing.T) {
 	_, ok := api.Cap[api.MaxACPowerGetter](m)
 	assert.True(t, ok, "MaxACPowerGetter")
 }
+
+func TestPVMaxACPowerPlugin(t *testing.T) {
+	newMeter := func(maxacpower any) api.Meter {
+		m, err := NewConfigurableFromConfig(t.Context(), map[string]any{
+			"power":      map[string]any{"source": "const", "value": 1000},
+			"maxacpower": maxacpower,
+		})
+		require.NoError(t, err)
+		return m
+	}
+
+	m := newMeter(map[string]any{"source": "const", "value": 5000})
+	mp, ok := api.Cap[api.MaxACPowerGetter](m)
+	require.True(t, ok, "MaxACPowerGetter")
+	assert.Equal(t, 5000.0, mp.MaxACPower())
+
+	// device without rating must not be decorated
+	m = newMeter(map[string]any{"source": "error", "error": "ErrNotAvailable"})
+	_, ok = api.Cap[api.MaxACPowerGetter](m)
+	assert.False(t, ok, "MaxACPowerGetter")
+}
 func TestBattery(t *testing.T) {
 	m, err := NewConfigurableFromConfig(t.Context(), map[string]any{
 		"power": map[string]any{

meter/usage_battery.go

@@ -43,11 +43,11 @@ func resolveFloat(ctx context.Context, v any) (func() float64, error) {
 	case nil:
 		return nil, nil
 	case int:
-		return staticCapacity(float64(v)), nil
+		return staticFloat(float64(v)), nil
 	case int64:
-		return staticCapacity(float64(v)), nil
+		return staticFloat(float64(v)), nil
 	case float64:
-		return staticCapacity(v), nil
+		return staticFloat(v), nil
 	default:
 		var cfg plugin.Config
 		if err := util.DecodeOther(v, &cfg); err != nil {
@@ -67,7 +67,7 @@ func resolveFloat(ctx context.Context, v any) (func() float64, error) {
 	}
 }
 
-func staticCapacity(f float64) func() float64 {
+func staticFloat(f float64) func() float64 {
 	if f == 0 {
 		return nil
 	}

meter/usage_pv.go

@@ -1,5 +1,11 @@
 package meter
 
+import (
+	"context"
+
+	"github.com/evcc-io/evcc/util"
+)
+
 type pvMaxACPower struct {
 	MaxACPower float64
 }
@@ -8,10 +14,23 @@ type pvMaxACPower struct {
 
 // Decorator returns the max AC power decorator
 func (m *pvMaxACPower) Decorator() func() float64 {
-	if m.MaxACPower == 0 {
-		return nil
-	}
-	return func() float64 {
-		return m.MaxACPower
-	}
+	return staticFloat(m.MaxACPower)
+}
+
+type pvMaxACPowerCtx struct {
+	MaxACPower any // static W value or float plugin
+}
+
+// var _ api.MaxACPowerGetter = (*pvMaxACPowerCtx)(nil)
+
+// Decorator returns the max AC power decorator. MaxACPower may be a static value or a
+// float plugin like the SunSpec nameplate rating. Since the rating is constant, the
+// plugin is read once. Unavailable or zero means not configured.
+func (m *pvMaxACPowerCtx) Decorator(ctx context.Context) func() float64 {
+	get, err := resolveFloat(ctx, m.MaxACPower)
+	if err != nil {
+		// not all devices expose the rating- must not fail configuration
+		util.NewLogger("meter").WARN.Printf("maxacpower: %v", err)
+	}
+	return staticFloat(floatOr0(get))
 }