04 Apr Is electricity power or energy?
Electricity – for most of us – is taken for granted so much that we rarely give any thought to what it is and where it comes from. The modernity of our lifestyles has dictated such a high level of expectation that we don’t think twice about the power that gets delivered to our appliances, simply because we demand it – and it arrives in an instant!
Ironically, it’s not that straightforward when it comes to answering the question: what is electricity? The reason is that electricity has a collective meaning and is not easy to pin down unless you get to talking about a range of specifics. Generally though, electricity is thought of as either power or energy. It is quite common to confuse these terms but they are two different things. The term ‘electricity’ therefore has to be qualified by the context of what is taking place: there is a rate of power and a flow of energy.
Power is a rating of output while energy is the measure of how much of that power is generated or consumed. Our power for example, is rated in kilowatts. And energy is measured in kilowatt hours – the amount of work that power does over time. For example, a light bulb may have a power rating of 100W but the bulb’s energy use over one hour is 100W-hours (0.1 KWh or 0.1 unit). Put another way, this same amount of energy would light a 50W bulb for two hours.
Te Aponga Uira generates this energy using diesel-fueled engines, which act as the ‘prime mover’ to make the power (the potential energy) move. The chemical energy of diesel is used as mechanical energy to convert power into electrical energy. The right level of voltage pushes the energy around the network, in the form of AC power – the alternating current for everyday use.