Measuring and monitoring
Plug-in mains power and energy monitor
These are very useful to measure the electricity consumption of any gadget plugged into the mains. It's been very helpful to us in identifying improvements, notably that our electric towel rail was consuming around a quarter of our total electricity use! At first we installed a time clock to reduce this but then we decided we didn't actually need it at all.
Electricity monitors (also sometimes referred to as smart meters) are designed to show how much electricity is currently being used as it senses the current flowing in the mains supply. It is useful as a wake-up call to how much is being used but does have some limitations, for example, it isn't really sensitive enough to see small changes due to appliances like a TV being switched on or off. Also it isn't sensitive to the direction of current flow so when the PV panels are generating this appears to show up as electricity consumption! Further information about the limitations.
This gave us plenty of ideas for heat loss areas to tackle, e.g. wall areas that were particularly cold.