Differential or economy 7 tariffs, charge less for electricity between midnight and 6:30am (8p/kWh), and slightly more for the rest of the day (13p/kWh), compared with normal tariffs which charge the same rate all day (12p/kWh). If you have a relatively high overnight usage, for example if you have storage heaters a differential tariff might reduce your electricity costs.
Energy Sparks looks at your daytime and night-time usage and works out using approximate tariffs whether it might be beneficial for your school to switch to a differential tariff, or from a non-differential tariff, and presents these calculations for each of your electricity meters below.
If Energy Sparks recommends that it might be beneficial to switch between differential tariff types you should get in contact with your supplier and ask for them to accurately estimate the cost benefits of switching. Given you have a smart or advanced meter providing half hourly meter readings, you shouldn't need a new meter.
In total Energy Sparks estimates you could save £12,782 if your school changed energy tariffs. This is 20% of your annual electricity bill by switching the meter(s) above. However, this doesn’t include any additional standing charge you might have to pay, which you will need to ask your supplier about.