@smappee/node-red-contrib-smappee-solar/example/EV charging.js

Solar nodes

const context = context
const flow = flow
const msg = msg

// Value to base charge level thresholds on
const thresholds = [
  [0, 80], // From 00:00 to the next
  [12, 50], // From 12:00 to the next
  [18, 80] // From 18:00 to end of day
]

// Smappee values
const production = msg.totalExportEnergy
const consumption = msg.totalImportEnergy
const excessProduction = production > consumption

// State variables
const lastUpdate = context.get('lastUpdate') || 0
const chargeLevel = flow.get('chargeLevel') || undefined
const chargingState = flow.get('chargingState') || false
const chargingMode = flow.get('chargingMode') || 'auto'

// Update state every 5 minutes if necessary
const shouldUpdate = (Date.now() - lastUpdate) > (5 * 60 * 1000)

// Message variables
let solarMsg = null
let evMsg = null

// Check if charge level should be updated
if (excessProduction && shouldUpdate) {
  solarMsg = {payload: true}
  context.set('lastUpdate', Date.now())
}

// Use the first value as the default
let threshold = thresholds[0][1]

// Dynamically determine appropriate threshold value
const hours = new Date().getHours()
for (let i = 1; i < thresholds.length; i++) {
  let condition = thresholds[i][0]

  // Always pick last applicable condition
  if (hours <= condition) {
    threshold = thresholds[i][1]
  }
}

// Determine if EV should be turned on
if (chargingMode === 'auto') {
  if (excessProduction && !chargingState && chargeLevel > threshold) {
    evMsg = {payload: true}
  } else if (!excessProduction || (chargingState && chargeLevel <= threshold)) {
    evMsg = {payload: false}
  }
} else if ((chargingMode === 'on' && !chargingState) || (chargingMode === 'off' && chargingState)) {
  evMsg = {payload: chargingMode === 'on'}
}

return [solarMsg, evMsg, {payload: chargingMode}]