Usage Profile

Knowing your Usage Profile will help you to understand when and where you are using energy in your household or business, enabling you to consider behavioural change eg. considering using the washing-machine at a different time of day..

You can build that understanding of your energy use by keeping track, either simply by checking your electricity bills to see how many units you've consumed or by different types of monitoring which will give you data on your usage as you use it.

Monitoring is possible at different levels, from a small device connected to the meter-feed to measure total usage or by , as would happen in a larger business, connecting a device, a meter, to each appliance


Voltage Optimisation

Voltage coming into the premises can vary in a range of from 240V down to 215V so to get best and most cost-effective performance from your appliances, the voltage should be optimised to run at a steady 220V. Industry uses voltage optimisation for iits machines, and voltage optimisation units are now available as small domestic units easily installed in a home or small business

When analysing the effects of supply voltage variation on power consumption and ultimately cost to the consumer it is found that domestic appliances can be divided into 3 general types i.e. Resistive, Inductive and Electronic

Resistive devices have a prime function to produce light and heat and make up 60% to 80% of most household energy usage

The inductive devices are often those with some form of electric motor whose output is that of mechanical work albeit that work may be used to provide heating or cooling as in the case of refrigerators and air conditioners. These devices contribute between 10% to 40% of household energy use

The electronic devices form part of entertainment systems in the home but are becoming more common in all appliances where some form of control is required

These are normally low power devices and rarely contribute more than 20% to the energy cost


Efficient Appliances

Developments in design of domestic appliances means that, for example, the latest energy-efficient refrigerators, for example, use 40 percent less energy than conventional models did in 2001

Following this, if all households in Europe changed their more than ten year old appliances into new ones, 20 billion kWh of electricity would be saved annually, hence reducing CO2 emissions by almost 18 billion kg

According to a 2009 study from McKinsey & Company the replacement of old appliances is one of the most efficient global measures to reduce emissions of greenhouse gases

Appliance Usage

The amount of energy used by each appliance depends on how much power it draws when in operation and how much of the time it is used.

The power usage is measured in watts and kilowatts (a kilowatt =1000 watts), and the amount of energy that it consumes in watt-hours or kilowatt hours (kWh).

A single bar electric fire often uses electricity at the rate of one kilowatt (kW) per hour. So, in an hour an electric fire will use one kilowatt hour (kWh). One kilowatt hour is also referred to as a ‘unit’ of electricity. In 2010 this costs an average of around 13p.

This table shows how various energy-using devices in the home compare - the amounts obviously vary according to how energy efficient your appliances are and how often you use them, but this should give you an indication.

ApplianceAnnual estimates (2010)

Uses/ hours kW per use/ hour Total kWh Total cost (£)1
30 year old fridge freezer 8760 0.14 1209 £160
Standard 60W bulbs (4 @ 6hrs/day) 8760 0.06 526 £69
Fridge-freezer A2 8760 0.05 412 £54
Tumble dryer 148 2.50 370 £49
Electric hob 424 0.71 301 £40
Electric oven 135 1.56 211 £28
Fridge Freezer A++ 8760 0.02 206 £27
Kettle 1542 0.11 170 £22
Washing Machine
187 0.63 118 £16
Dishwasher (55°C) 110 1.07 118 £16
Low energy 11W bulbs (4 @ 6hrs/day) 8760 0.01 96 £13
Microwave oven 96 0.95 91 £12
1 £0.1321 per kWh 2009 UK price including tax from Table 5.51 above
2 Usage rates and energy consumption adapted from Note addition of 30yo fridge (t2c) and lightbulbs (OG)


This table highlights the high energy cost of appliances that are kept plugged in and run 24 hours a day throughout the year and the huge savings that can be made.

The difference between the cost of running a 30 year old and a fairly standard modern ‘A’ rated freezer is £106/year. A super-efficient A++ rated fridge freezer would save £133/year at 2010 electricity prices.

Energy usage chart


Modern power management systems also reduce energy usage by idle appliances by turning them off or putting them into a low-energy mode after a certain time



Monitoring and establishing your energy Usage Profile will help you to understand how much and when you are consuming electricity and other forms of energy, such as gas


Our enData service is simple to use:

Data for setting up your Usage-Profile is obtained by monitoring your supply coming into your home, or other type of building

Once you have the data,  usually presented in chart form making it easy to see at a glance when you're going "over the line", you can decide if you need to make adjustments to the way, and to when,  you're using electricity, and/or gas

The charts can be viewed on your computer screen both off-line and online through a connection throuhgh the Internet

Data can also be presented in analsysis sheets to print off and study or to view on screen


Example: the charts show a household's temperature movements and electricity use in a month

Zoomable Temperature



Zoomable Electricity Consumption
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