Monitoring and metering your energy use

How to gather and use energy usage data


To manage your energy usage well you need to measure your consumption accurately and interpret the results.

Reading your energy meter

Your energy bills show your energy consumption and the current tariffs. It's important to check your bill against your meter reading to make sure you're only paying for what you're using.

Digital meters are straightforward, but the old dial meters (analogue) can be more difficult to check. To read an analogue meter, start with the smallest unit first and read the dials in order. When the hand is between two numbers write down the number it has just passed. The 1/10 reading is generally ignored.

You should take meter readings regularly and you may need to install a half-hourly meter for greater accuracy.

Plot your energy data in a spreadsheet

To plot the data, record your meter readings as a graph of energy against time. Identify your 'base load' (the reading when no activity is taking place) and if it seems too high, look into it.

Where the graph shows high energy usage, check that this is what you would expect. If anything seems suspicious investigate further. You can also compare daily graphs to identify where inefficiencies are occurring.

Understanding energy bills

The type of bill you get depends on how much energy you use.

For electricity bills, your site is classified as 'code 5' or 'non code 5' depending on how much electricity you use:

  • code 5 bills are itemised by how much electricity is used at specific times and how much it costs
  • non code 5 bills are less detailed and are based on either physical meter readings or an estimated level of consumption

The type of gas bill you get depends on whether you are classed as a large consumer. Large consumers' bills are generally based on daily meter readings and show the consumption and how much it costs. Other consumers' bills are sent monthly or quarterly, based on actual or estimated readings.