This section is planned to give you a brief overview of some of the more commonly used ways of saving energy in printers. The links will help find futher information about each. More ideas will be added over time.

In addition to the sources of information listed on the right, your energy supplier may be able to offer you advice and even a free survey to check for poor power factor.

Carbon Trust, in addition to having a wealth of information on their site, also offer interest free loans on some energy saving investments - you pay the loan back from the savings you make.

Voltage optimisation

The principle behind voltage optimisation is fairly straightforward. For many years the UK had a standardised supply voltage of around 240V, whereas in continental Europe the level was 220V. In Europe the supply has now been harmonised to 230V plus or minus 10%, giving a range of 207 - 253V. The width of this range means that actual supplies have remained largely unchanged.

The average in the UK is still around 242V, yet much of the equipment we use was designed to work at 220V.

Such equipment is therefore drawing more power than it really needs, which has two effects:

• It costs you more than it should in energy consumption
• It wears out faster

This applies to many types of equipment used by printers, from fluorescent light tubes to printing presses.

Voltage optimisation works in one of two ways, both of which reduce how much power is used. One method is to reduce the voltage by a certain amount - a percentage that is set according to the level and variability of your supply and  the needs of your equipment - and the other is to reduce the voltage to a certain amount, so that even if the incoming supply varies, the supply to your equipment is constant. There are also 'in between' options with more than one reduction setting, that can be 'intelligently' selected by the equipment according to voltage levels.

The savings to be made will vary according to the type of equipment you are running, as well as how much energy you use, as some presses, compressors, IT equipment, lighting and so on may already have energy saving measures in place.

Power factor correction

Power factor correction is another way of reducing the amount of power drawn from your supplier.

Power factor is related to efficiency - it is the ratio of real (working) power, measured in kW, to total (or apparent) power, measured in kVA, drawn from an AC supply. You may be drawing more reactive power than is actually needed, thus increasing the total power and possibly attracting extra charges.

Some types of equipment, such as heating elements, may draw only working power. Others, such as motors, compressors and fluorescent lights, draw a certain amount of reactive power to generate the magnetic fields they need to operate.
The ideal power factor - known as unity power factor - is 1.0, but the nature of some types of equipment is such that this may not be achievable. However, it may be possible to improve the power factor. A power factor below 0.85 is generally considered to be poor, and correction worthwhile. Correction can, in the right circumstances, improve the power factor, achieving a level of 0.95 to 0.98, with consequent savings in your energy bills.

Power factor may be improved to an extent by voltage optimisation, but not necessarily to the optimum extent as that is not its purpose. The most basic means of correction is by fitting capacitors, either to a specific piece of equipment or to the incoming power supply.