Use PV Forecast for EV Charging or Heatpump scheduling

README.md

**Electric vehicles and heat pumps are consumers which can very easily be used for demand-side management. In order to maximize use of local electricity generated by photovoltaics and minimize the amount of electricity from the grid, a scheduler plans and organizes time slots. **

This flow shows the concepts and introduces the actual scheduling function. It is designed as an easy to adopt prototype for intermidiate users of Node-RED. In order to get this scheduler working, a free RapidAPI-Key for the PV forecast system is required. You could get it here and register for the SolarEnergyPrediction API.

Setup / Configuration

Open the SEP-API Call node and its configuration. Create a new RapidAPI Credentials with an API-key to use with the SolarEnergyPrediction service.

Configure your PV-generation plant in the PV Settings node.

msg.payload = {
    "lat": 49.3418836,  // latitude of geolocation
    "lon": 8.8006813,   // longitude of geolocation
    "deg": 35,     // tilt degrees of pv panels (0=horiziontal)
    "az": 45, // azimuth (0=south, 90 = west, -90 = east)
    "wp": 5060 // WattPeak of generator
}
return msg;

Usage

Trigger the flow using the inject node Retrieve Forecast. After a few seconds the scheduler calculates the optimum times and stores them in a context-data object of the flow called prediction.

For easy re-use you might inject Retrieve Schedule which will display a formal schedule with the on/off switches for the two pre-configured devices.

Additional devices might be added using the same schema. There is no UI!

Questions?

Do not hesitate to contact dev@stromdao.com.

flow.json

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        "id": "c034943b78abeaa2",
        "type": "tab",
        "label": "PV Prediction",
        "disabled": false,
        "info": "Sample flow to see how to retrieve a solar plant prediction and use it for scheduling of larger devices (like EV charging or heatpump).\r\n",
        "env": []
    },
    {
        "id": "33570a6660ac8b9a",
        "type": "RapidAPI",
        "z": "c034943b78abeaa2",
        "name": "SEP-API Call",
        "account": "fcd26d2128b2396f",
        "url": "https://solarenergyprediction.p.rapidapi.com/v2.0/solar/prediction",
        "method": "GET",
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        "y": 80,
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        "type": "inject",
        "z": "c034943b78abeaa2",
        "name": "Retrieve Forecast",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "topic",
                "vt": "str"
            }
        ],
        "repeat": "3600",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 170,
        "y": 80,
        "wires": [
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    {
        "id": "f5bd6dd8b5d8fd97",
        "type": "function",
        "z": "c034943b78abeaa2",
        "name": "Store in Flow",
        "func": "await flow.set(\"prediction\",msg.payload.output);\nconst forecast = msg.payload.output;\n\nlet avail = 0;\nfor (let i = 0;\n    (i < forecast.length) &&\n    (forecast[i].timestamp < new Date().getTime() + 86400000);\n    i++) {\n    if ((forecast[i].timestamp > new Date().getTime() - 3600000) && (forecast[i].wh > 0)) {\n        avail += 1 * forecast[i].wh;    \n    }\n}\nlet fill = \"green\";\n\nnode.status({ fill: fill, shape: \"ring\", text: avail + \" available.\" });\nflow.set(\"devices\",{});\nreturn msg;",
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        "finalize": "",
        "libs": [],
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    {
        "id": "3fcc1f84753c3656",
        "type": "comment",
        "z": "c034943b78abeaa2",
        "name": "Retrieve Generation Forecast",
        "info": "",
        "x": 180,
        "y": 40,
        "wires": []
    },
    {
        "id": "9dba8be5fe7326dd",
        "type": "comment",
        "z": "c034943b78abeaa2",
        "name": "Schedule Devices",
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        "y": 160,
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    {
        "id": "aada8def46d86c4d",
        "type": "function",
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        "func": "const forecast = await flow.get(\"prediction\");\nlet devices = await flow.get(\"devices\");\nif((typeof devices == 'undefined') || (devices == null)) devices = {};\n\nlet relevantHours = [];\nfor(let i=0;\n        (i<forecast.length) &&  \n        (forecast[i].timestamp < new Date().getTime() + msg.payload.timeframe);\n    i++) {\n    if ((forecast[i].timestamp > new Date().getTime() - 3600000) && (forecast[i].wh>0)) {\n        relevantHours.push(forecast[i]);\n    }\n}\n\nrelevantHours.sort(function (a, b) {\n    return b.wh - a.wh;\n});\n\nlet requiredWh = msg.payload.requiredWh * 1;\nlet used = 0;\n\ndevices[msg.payload.device] = requiredWh;\n\nfor(let i=0;(i<relevantHours.length) && (requiredWh > 0);i++) {\n    if(requiredWh > 0) {\n        let using = msg.payload.avgWatt;\n        if (using > requiredWh) using = requiredWh;\n        requiredWh -= using;\n        used += using;\n        relevantHours[i].wh -= using;\n        if (typeof relevantHours[i].usedBy == 'undefined') {\n            relevantHours[i].usedBy = {};\n        }\n        relevantHours[i].usedBy[msg.payload.device] = using;\n    }\n}\n\nlet remain = 0;\nfor (let i = 0;\n    (i < forecast.length);\n    i++) {\n    \n    if(forecast[i].timestamp < new Date().getTime() + msg.payload.timeframe) {     \n        for(let j=0;j<relevantHours.length;j++) {\n            if(relevantHours[j].timestamp == forecast[i].timestamp) {\n                node.log(\"rhWh\" + relevantHours[j].wh);\n                forecast[i].wh = relevantHours[j].wh;\n                remain += forecast[i].wh;\n            }\n        }\n    }\n}\n\nawait flow.set(\"prediction\", forecast);\nlet fill=\"red\";\nif(remain > 0) fill=\"green\";\n\nnode.status({ fill: fill, shape: \"ring\", text: used +\" used / \"+remain+\" unused.\"});\nawait flow.set(\"devices\",devices);\n\nmsg.payload = relevantHours;\nreturn msg;",
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        "finalize": "",
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        "wires": [
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    {
        "id": "20ff9e7579cc6a9f",
        "type": "function",
        "z": "c034943b78abeaa2",
        "name": "Settings: Device 2 - Heatpump",
        "func": "msg.payload = {\n    \"device\": \"Device_2_heatpump\",\n    \"requiredWh\": 5000,\n    \"avgWatt\": 2500,\n    \"timeframe\": 86400000\n};\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 210,
        "y": 300,
        "wires": [
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                "e7d53e54f786dd84"
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    {
        "id": "e4b94d2841fd7d26",
        "type": "function",
        "z": "c034943b78abeaa2",
        "name": "Settings: Device 1 Car ",
        "func": "msg.payload = {\n    \"device\": \"Device_1_car\",\n    \"requiredWh\": 18000,\n    \"avgWatt\": 2100,\n    \"timeframe\": 86400000\n};\n\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 180,
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        "wires": [
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    },
    {
        "id": "29e3f22863574168",
        "type": "function",
        "z": "c034943b78abeaa2",
        "name": "PV Settings",
        "func": "msg.payload = {\n    \"lat\": 49.3418836,\n    \"lon\": 8.8006813,\n    \"deg\": 35,\n    \"az\": 45,\n    \"wp\": 5060\n}\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 410,
        "y": 80,
        "wires": [
            [
                "33570a6660ac8b9a"
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    },
    {
        "id": "e7d53e54f786dd84",
        "type": "function",
        "z": "c034943b78abeaa2",
        "name": "Optimize Schedule",
        "func": "const forecast = await flow.get(\"prediction\");\nlet devices = await flow.get(\"devices\");\nif ((typeof devices == 'undefined') || (devices == null)) devices = {};\n\nlet relevantHours = [];\nfor (let i = 0;\n    (i < forecast.length) &&\n    (forecast[i].timestamp < new Date().getTime() + msg.payload.timeframe);\n    i++) {\n    if ((forecast[i].timestamp > new Date().getTime() - 3600000) && (forecast[i].wh > 0)) {\n        relevantHours.push(forecast[i]);\n    }\n}\n\nrelevantHours.sort(function (a, b) {\n    return b.wh - a.wh;\n});\n\nlet requiredWh = msg.payload.requiredWh * 1;\nlet used = 0;\n\ndevices[msg.payload.device] = requiredWh;\n\nfor (let i = 0; (i < relevantHours.length) && (requiredWh > 0); i++) {\n    if (requiredWh > 0) {\n        let using = msg.payload.avgWatt;\n        if (using > requiredWh) using = requiredWh;\n        requiredWh -= using;\n        used += using;\n        relevantHours[i].wh -= using;\n        if (typeof relevantHours[i].usedBy == 'undefined') {\n            relevantHours[i].usedBy = {};\n        }\n        relevantHours[i].usedBy[msg.payload.device] = using;\n    }\n}\n\nlet remain = 0;\nfor (let i = 0;\n    (i < forecast.length);\n    i++) {\n\n    if (forecast[i].timestamp < new Date().getTime() + msg.payload.timeframe) {\n        for (let j = 0; j < relevantHours.length; j++) {\n            if (relevantHours[j].timestamp == forecast[i].timestamp) {\n                node.log(\"rhWh\" + relevantHours[j].wh);\n                forecast[i].wh = relevantHours[j].wh;\n                remain += forecast[i].wh;\n            }\n        }\n    }\n}\n\nawait flow.set(\"prediction\", forecast);\nlet fill = \"red\";\nif (remain > 0) fill = \"green\";\n\nnode.status({ fill: fill, shape: \"ring\", text: used + \" used / \" + remain + \" unused.\" });\nawait flow.set(\"devices\", devices);\n\nmsg.payload = relevantHours;\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 650,
        "y": 300,
        "wires": [
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        ]
    },
    {
        "id": "ae5eff12cbab70a7",
        "type": "function",
        "z": "c034943b78abeaa2",
        "name": "Format Schedule",
        "func": "const forecast = await flow.get(\"prediction\");\nconst devices = await flow.get(\"devices\");\n\nlet rows = [];\n\nfor(let i=0;((i<forecast.length) && (forecast[i].timestamp < new Date().getTime()+86400000));i++) {\n    if(forecast[i].timestamp > new Date().getTime()-3600000) {\n        let row = {\n            timestamp:forecast[i].timestamp,\n            unscheduledWh:forecast[i].wh,\n            devices: {}\n        };\n\n        if(typeof forecast[i].usedBy !== 'undefined') {\n            for (const [key, value] of Object.entries(devices)) {\n                if(typeof forecast[i].usedBy[key] !== 'undefined') {\n                    row.devices[key] = 1;\n                } else {\n                    row.devices[key] = 0;\n                }\n            }\n        } else {\n            for (const [key, value] of Object.entries(devices)) {\n                row.devices[key] = 0;\n            }\n        }\n\n        rows.push(row);\n    }\n}\n\nmsg.payload = rows;\n\nreturn msg;",
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        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 650,
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                "2a1f1a3fc352e07d"
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        "z": "c034943b78abeaa2",
        "name": "Retrieve Schedule",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "topic",
                "vt": "str"
            }
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        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
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    {
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        "type": "comment",
        "z": "c034943b78abeaa2",
        "name": "Show in Console",
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        "y": 400,
        "wires": []
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    {
        "id": "2a1f1a3fc352e07d",
        "type": "debug",
        "z": "c034943b78abeaa2",
        "name": "Debug View",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "payload",
        "targetType": "msg",
        "statusVal": "",
        "statusType": "auto",
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        "wires": []
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    {
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        "type": "rapidapi-config",
        "name": "SEP-API"
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]