Site simulator: thermal plant, facility presets, and live schematic

.gitignore

@@ -59,8 +59,10 @@ coverage.xml
 .pytest_cache/
 cover/
 
-# Translations
+# Translations (gettext). Keep Modelica sources.
 *.mo
+!modelica/
+!modelica/*.mo
 *.pot
 
 # Django stuff:
@@ -177,3 +179,20 @@ data/state.json
 
 # Go binaries
 /simulator
+
+# OpenModelica / FMI build products (compile locally with `make fmu`)
+modelica/*.fmu
+modelica/Site4_*
+modelica/*.inst.mo
+modelica/*.libs
+modelica/*.makefile
+modelica/*.json
+modelica/*.html
+modelica/*.c
+modelica/*.h
+modelica/*.o
+modelica/*.xml
+modelica/*.log
+modelica/*.exe
+modelica/*.so
+

CLAUDE.md

@@ -99,6 +99,7 @@ The app supports two modes controlled by the `--desktop` flag:
 - Pixii PowerShaper
 - FerroAmp EnergyHub
 - SDM630 Energy Meter
+- Generic SG Ready heat pump (site plant)
 
 ## API Endpoints
 
@@ -107,7 +108,7 @@ HTTP API (port 80 in Docker, 8762 in desktop mode):
 ```
 GET  /                                    # Dashboard UI
 GET  /api/simulators                      # List all simulators
-POST /api/simulators                      # Create simulator {type: "inverter"|"energy_meter"|"v2x_charger"|"ocpp_charger"}
+POST /api/simulators                      # Create simulator {type: "inverter"|"energy_meter"|"heat_pump"|"v2x_charger"|"ocpp_charger"}
 DELETE /api/simulators/{id}               # Delete simulator
 GET  /api/simulators/{id}                 # Get simulator details
 POST /api/simulators/{id}/config          # Update serial/slave ID
@@ -119,6 +120,10 @@ POST /api/simulators/{id}/automation/stop  # Stop data generation
 POST /api/simulators/{id}/reset           # Reset to defaults
 GET  /api/sites                           # List all sites
 POST /api/sites                           # Create site
+GET  /api/facilities                      # List facility presets
+GET  /api/sites/{id}/facility             # Get site facility
+POST /api/sites/{id}/facility             # Apply facility preset (plant + devices)
+GET  /api/sites/{id}/plant                # Live electrical + thermal snapshot
 GET  /api/system                          # Get system info (local IP)
 GET  /api/version                         # Get app version
 GET  /api/update/check                    # Check for updates

Makefile

@@ -1,6 +1,6 @@
 .PHONY: up down restart build logs clean test env \
 	build-macos build-linux build-linux-server build-windows \
-	run-macos package help
+	run-macos package help fmu fmu-clean
 
 # Auto-detect host IP for Mac (en0 = WiFi, en1 = Ethernet)
 HOST_IP ?= $(shell ipconfig getifaddr en0 2>/dev/null || ipconfig getifaddr en1 2>/dev/null || echo "")
@@ -32,6 +32,17 @@ clean:
 test:
 	go test ./...
 
+# Compile modelica/SiteEnergy.Site4 to an FMI 2.0 co-simulation FMU.
+# Requires OpenModelica (`omc`). The simulator loads it via siteplant.Open.
+fmu:
+	@command -v omc >/dev/null || (echo "omc not found. Install OpenModelica: https://openmodelica.org" && exit 1)
+	cd modelica && omc export.mos
+
+fmu-clean:
+	cd modelica && rm -f Site4.fmu Site4_*.c Site4_*.h Site4_*.o Site4_*.json \
+		Site4_*.libs Site4_*.makefile Site4_*.log Site4.inst.mo index.html \
+		Site4_FMU.* 2>/dev/null || true
+
 # Build macOS desktop app (native, requires macOS)
 build-macos:
 	@echo "Building macOS desktop app..."
@@ -126,5 +137,6 @@ help:
 	@echo ""
 	@echo "Other:"
 	@echo "  make test         - Run Go tests"
+	@echo "  make fmu          - Compile SiteEnergy.Site4 to FMI 2.0 CS (needs omc)"
 	@echo "  make package      - Create release packages"
 	@echo "  make clean        - Remove build artifacts"

README.md

@@ -63,6 +63,8 @@ docker compose up --build
 - **Site Management** - Group simulators into sites with energy meters
 - **Device Profiles** - Sungrow, SolarEdge, Fronius, Huawei, and more
 - **Time Acceleration** - Compress 24 hours into minutes for testing
+- **Physical plant** - Site AC bus with conserved power and battery SoC. Modelica in `modelica/SiteEnergy.mo`; compile with `make fmu` and plug in via `siteplant`. Sketch: [docs/SITE_PLANT_SKETCH.md](docs/SITE_PLANT_SKETCH.md)
+- **Site simulator** - Facility presets (ASHP/GSHP, occupancy, DHW) behind Modbus facades so an EMS can treat the process as a real site. [docs/SITE_SIMULATOR.md](docs/SITE_SIMULATOR.md)
 - **Real-time Logging** - See every protocol operation as it happens
 
 ## Supported Profiles
@@ -79,6 +81,7 @@ docker compose up --build
 | deye | Deye hybrid inverter |
 | pixii-powershaper | Pixii PowerShaper |
 | ferroamp | FerroAmp EnergyHub |
+| heat-pump | Generic SG Ready heat pump (site plant) |
 | sdm630 | SDM630 Energy Meter |
 
 > **Disclaimer:** Device Simulator is an independent testing tool and is **not affiliated with, endorsed by, or sponsored by** any of the manufacturers listed above. Product and company names are trademarks of their respective owners and are used only to identify the device behavior being simulated.

cmd/simulator/app.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/srcfl/device-simulator/internal/modbus"
 	"github.com/srcfl/device-simulator/internal/modbus/devices"
+	"github.com/srcfl/device-simulator/internal/plant"
 	"github.com/srcfl/device-simulator/internal/settings"
 	"github.com/wailsapp/wails/v2/pkg/runtime"
 )
@@ -732,6 +733,7 @@ func (a *App) GetSites() []map[string]interface{} {
 			"time_multiplier": site.TimeMultiplier,
 			"sim_running":     site.SimRunning,
 			"scenario":        site.Scenario,
+			"facility_id":     site.FacilityID,
 		}
 		p1Mode := P1ModeDirect
 		if site.P1Buffer != nil {
@@ -818,6 +820,8 @@ func (a *App) GetSite(id int) (map[string]interface{}, error) {
 		"phase_loads":     site.SitePhaseLoads,
 		"load_scenario":   site.LoadScenario,
 		"load_linked":     site.LoadLinked,
+		"facility_id":     site.FacilityID,
+		"plant":           site.lastPlant,
 	}
 
 	meterID := site.MeterID
@@ -1181,15 +1185,15 @@ func (a *App) CreateSimulatorInSite(siteId int, simType string) (map[string]inte
 	a.emitSiteUpdate()
 
 	return map[string]interface{}{
-		"id":             sim.ID,
-		"serial":         sim.Serial,
-		"protocol":       sim.Protocol,
-		"category":       sim.Category,
-		"port":           sim.Port,
-		"running":        sim.Running,
-		"site_id":        siteId,
-		"device_on":      sim.DeviceOn,
-		"mdns_hostname":  mdnsAdvertiser.ActiveHostname(sim.ID),
+		"id":            sim.ID,
+		"serial":        sim.Serial,
+		"protocol":      sim.Protocol,
+		"category":      sim.Category,
+		"port":          sim.Port,
+		"running":       sim.Running,
+		"site_id":       siteId,
+		"device_on":     sim.DeviceOn,
+		"mdns_hostname": mdnsAdvertiser.ActiveHostname(sim.ID),
 	}, nil
 }
 
@@ -1547,3 +1551,35 @@ func (a *App) SetSiteLoadScenario(id int, scenario string) (map[string]interface
 
 	return result, nil
 }
+
+// GetFacilities returns site physics templates (heat pumps, loads, envelope).
+func (a *App) GetFacilities() []plant.Facility {
+	return plant.Presets()
+}
+
+// ApplySiteFacility instantiates a facility preset on a site (devices + plant).
+func (a *App) ApplySiteFacility(id int, preset string) (map[string]interface{}, error) {
+	site := getSite(id)
+	if site == nil {
+		return nil, fmt.Errorf("site %d not found", id)
+	}
+	if err := applyFacilityPreset(site, preset); err != nil {
+		return nil, err
+	}
+	if err := startSiteSimulationWithServers(site); err != nil {
+		log.Printf("[Site %d] start after facility: %v", id, err)
+	}
+	markStateDirty()
+	a.emitSimulatorUpdate()
+	a.emitSiteUpdate()
+	return sitePlantJSON(site), nil
+}
+
+// GetSitePlant returns the live physics snapshot for the schematic.
+func (a *App) GetSitePlant(id int) (map[string]interface{}, error) {
+	site := getSite(id)
+	if site == nil {
+		return nil, fmt.Errorf("site %d not found", id)
+	}
+	return sitePlantJSON(site), nil
+}