CHAPTER 1: WHAT IS “ENERGY EFFICIENCY”?

The term “energy efficiency” is currently being bandied around a lot in the trade press and in meetings. Before we progress, this term needs to be reviewed, as it can give an insight into the work that needs to be done.

Energy versus power

Firstly, when energy is discussed we are talking about power (watts) over a period of time. Thus, energy is typically reported in kilowatt hours, (kWh), bearing in mind the following equation:

kWh = (Watts × Duration of use in hours) / 1000.

This is an important point – energy is a combination of power and time. All things being equal, if we decrease either, then we decrease the energy used. If we can cut both the wattage and the duration of use, then the results ...

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