Get all meter readings from Switch2 MeterReadings page

meter-readings.js

// For use on https://my.switch2.co.uk/MeterReadings/History
// Prints out a CSV which you can save to a file and then upload to something like https://www.csvplot.com/

data = Array.from(document.querySelectorAll(".meter-reading-history-table-data-row.desktop-layout")).map(function (row) {
  return {
    date: row.querySelector(".meter-reading-history-table-data-date-row-item").innerText,
    amount: parseInt(row.querySelector(".meter-reading-history-table-data-amount-row-item").innerText)
  }
}).reverse()

console.log("Date,Usage (kWh),Delta (kWh)\n" + data.map((row, index) => {
  let prev = data[index - 1]
  return row.date + "," + row.amount + "," + (prev ? row.amount - prev.amount : 0)
}).join("\n"))