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Add EV charging advice notification to status page

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Uses hourly PV forecast data (watts per hour from forecast.solar) to
find the first contiguous block of hours where:
  PV production - base_load_w >= min_surplus_w

Shows a blue advice card on the status page:
  "Auto einstecken bis HH:MM Uhr"
  "Erwartetes Überschuss-Fenster: HH:MM – HH:MM Uhr"

Card is hidden when:
- No surplus window found (weak forecast day)
- Window has already started or passed
- A wallbox is currently active (car already charging)

Config: forecast.base_load_w (1000W), forecast.min_surplus_w (1800W)
Timestamp parsing handles both "HH:MM:SS" and "HH:MM" key formats.
Today: surplus window 11:00–13:00 (24.3 kWh forecast).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
Lutz FInsterle
2026-04-06 10:30:58 +02:00
parent 5f22df3e0f
commit 0020f1268b
4 changed files with 143 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
configs/ems-config.yaml
View File

@@ -98,6 +98,8 @@ forecast:
fetch_interval: "4h" # re-fetch during the day (free tier: 12 req/day → 3 fetches)
fetch_window_start: "07:00"
fetch_window_end: "19:00"
base_load_w: 1000 # typical house consumption used for surplus estimate (W)
min_surplus_w: 1800 # min export surplus to trigger wallbox — matches wallbox_a threshold
# EMS operational settings
ems:

14
internal/config/config.go
View File

@@ -131,12 +131,14 @@ type ForecastConfig struct {
Enabled bool `yaml:"enabled"`
Lat float64 `yaml:"lat"`
Lon float64 `yaml:"lon"`
Declination int `yaml:"declination"` // panel tilt in degrees
Azimuth int `yaml:"azimuth"` // degrees from south (south=0, west=90)
KWp float64 `yaml:"kwp"` // installed peak power
FetchInterval string `yaml:"fetch_interval"` // how often to re-fetch during the day (e.g. "4h")
FetchWindowStart string `yaml:"fetch_window_start"` // e.g. "07:00" — no fetches before this
FetchWindowEnd string `yaml:"fetch_window_end"` // e.g. "19:00" — no fetches after this
Declination int `yaml:"declination"` // panel tilt in degrees
Azimuth int `yaml:"azimuth"` // degrees from south (south=0, west=90)
KWp float64 `yaml:"kwp"` // installed peak power
FetchInterval string `yaml:"fetch_interval"` // how often to re-fetch during the day
FetchWindowStart string `yaml:"fetch_window_start"` // e.g. "07:00"
FetchWindowEnd string `yaml:"fetch_window_end"` // e.g. "19:00"
BaseLoadW float64 `yaml:"base_load_w"` // typical house consumption for surplus estimate (W)
MinSurplusW float64 `yaml:"min_surplus_w"` // min export needed to trigger wallbox charging (W)
}
func (f *ForecastConfig) FetchIntervalParsed() time.Duration {

72
internal/forecast/forecast.go
View File

@@ -6,6 +6,8 @@ import (
"fmt"
"log/slog"
"net/http"
"sort"
"strings"
"sync"
"time"
@@ -14,9 +16,11 @@ import (
// Result holds the fetched forecast for a single day.
type Result struct {
Date time.Time
TotalKWh float64
FetchedAt time.Time
Date time.Time
TotalKWh float64
FetchedAt time.Time
SurplusWindowStart time.Time // first hour where PV surplus exceeds wallbox threshold
SurplusWindowEnd time.Time // last hour of that contiguous block
}
// Quality returns a human-readable label based on configured thresholds.
@@ -151,6 +155,7 @@ func parseTimeOfDay(s string, ref time.Time) (time.Time, error) {
// forecastResponse is the forecast.solar API response structure.
type forecastResponse struct {
Result struct {
Watts map[string]float64 `json:"watts"` // instantaneous W per hour slot
WattHoursDay map[string]float64 `json:"watt_hours_day"`
} `json:"result"`
Message struct {
@@ -201,11 +206,72 @@ func (c *Client) fetch(ctx context.Context, day time.Time) (Result, error) {
FetchedAt: time.Now(),
}
// Compute surplus window if thresholds are configured
if c.cfg.MinSurplusW > 0 {
result.SurplusWindowStart, result.SurplusWindowEnd =
computeSurplusWindow(fr.Result.Watts, day, c.cfg.BaseLoadW, c.cfg.MinSurplusW)
}
c.logger.Info("forecast fetched",
"date", dateKey,
"kwh", result.TotalKWh,
"quality", result.Quality(c.strategic),
"surplus_start", formatOptionalTime(result.SurplusWindowStart),
"surplus_end", formatOptionalTime(result.SurplusWindowEnd),
)
return result, nil
}
// computeSurplusWindow finds the first contiguous block of hours in the hourly
// forecast where PV production minus house base load meets the minimum surplus
// threshold (i.e. enough export to charge a car).
// Returns zero times if no such window exists.
func computeSurplusWindow(watts map[string]float64, day time.Time, baseLoadW, minSurplusW float64) (start, end time.Time) {
type slot struct {
t time.Time
w float64
}
dayStr := day.Format("2006-01-02")
var slots []slot
for k, v := range watts {
if !strings.HasPrefix(k, dayStr) {
continue
}
// forecast.solar may return timestamps with or without seconds
t, err := time.ParseInLocation("2006-01-02 15:04:05", k, day.Location())
if err != nil {
t, err = time.ParseInLocation("2006-01-02 15:04", k, day.Location())
}
if err != nil {
continue
}
slots = append(slots, slot{t, v})
}
sort.Slice(slots, func(i, j int) bool {
return slots[i].t.Before(slots[j].t)
})
for _, s := range slots {
if s.w-baseLoadW >= minSurplusW {
if start.IsZero() {
start = s.t
}
end = s.t.Add(time.Hour)
} else if !start.IsZero() {
break // first contiguous block ended
}
}
return
}
func formatOptionalTime(t time.Time) string {
if t.IsZero() {
return "-"
}
return t.Format("15:04")
}

64
internal/status/status.go
View File

@@ -136,6 +136,13 @@ type forecastView struct {
Quality string
}
type chargingAdviceView struct {
Show bool
PlugInBy string // e.g. "11:30"
WindowStart string // e.g. "12:00"
WindowEnd string // e.g. "16:00"
}
type pageData struct {
LastUpdate time.Time
ErrMsg string
@@ -150,6 +157,7 @@ type pageData struct {
HasPhaseData bool
Phases []phaseView
Forecast forecastView
ChargingAdvice chargingAdviceView
Consumers []consumerView
}
@@ -253,6 +261,25 @@ func (s *Store) Handler() http.HandlerFunc {
Icon: s.fcResult.QualityIcon(s.strategic),
Quality: s.fcResult.Quality(s.strategic),
}
// Charging advice: show when surplus window is ahead and no wallbox is active
ws := s.fcResult.SurplusWindowStart
we := s.fcResult.SurplusWindowEnd
now := time.Now()
wallboxActive := s.consumers[engine.ConsumerWallboxA].active ||
s.consumers[engine.ConsumerWallboxB].active
if !ws.IsZero() && now.Before(ws) && !wallboxActive {
plugBy := ws.Add(-30 * time.Minute)
if plugBy.Before(now) {
plugBy = ws // less than 30 min to window — just show window start
}
data.ChargingAdvice = chargingAdviceView{
Show: true,
PlugInBy: plugBy.Format("15:04"),
WindowStart: ws.Format("15:04"),
WindowEnd: we.Format("15:04"),
}
}
}
for _, c := range consumerOrder {
rec := s.consumers[c]
@@ -415,6 +442,33 @@ h1 { font-size: 1.4rem; font-weight: 700; color: #14532d; }
margin-top: 0.1rem;
}
/* Charging advice card */
.advice-card {
background: #eff6ff;
border: 1px solid #bfdbfe;
border-radius: 14px;
padding: 0.85rem 1rem;
margin-bottom: 1.25rem;
}
.advice-title {
font-size: 0.78rem;
font-weight: 700;
color: #1d4ed8;
text-transform: uppercase;
letter-spacing: 0.05em;
margin-bottom: 0.4rem;
}
.advice-main {
font-size: 1rem;
font-weight: 700;
color: #1e3a8a;
}
.advice-sub {
font-size: 0.78rem;
color: #3b82f6;
margin-top: 0.2rem;
}
/* Live power badge on consumers */
.power-badge {
font-size: 0.72rem;
@@ -583,6 +637,16 @@ h1 { font-size: 1.4rem; font-weight: 700; color: #14532d; }
</div>
{{if .ChargingAdvice.Show}}
<div class="advice-card">
<div class="advice-title">🔌 Ladeempfehlung</div>
<div class="advice-main">Auto einstecken bis {{.ChargingAdvice.PlugInBy}} Uhr</div>
<div class="advice-sub">
Erwartetes Überschuss-Fenster: {{.ChargingAdvice.WindowStart}} – {{.ChargingAdvice.WindowEnd}} Uhr
</div>
</div>
{{end}}
<div class="section-title">Verbraucher</div>
{{range .Consumers}}