{"id":8103,"date":"2013-01-10T08:23:48","date_gmt":"2013-01-10T07:23:48","guid":{"rendered":"http:\/\/en.sma-sunny.com\/?p=8103"},"modified":"2017-12-13T15:58:31","modified_gmt":"2017-12-13T14:58:31","slug":"what-is-a-kilowatt-hour","status":"publish","type":"post","link":"https:\/\/www.sma-sunny.com\/en\/what-is-a-kilowatt-hour\/","title":{"rendered":"What Is a Kilowatt-hour?"},"content":{"rendered":"

Have you ever found yourself asking this question? It is a unit \u2013 correct. It has something to do with electric current \u2013 also correct. However, surely only a few of us are able to explain, off the top of our heads, what can actually be done with a kilowatt-hour. We are, therefore, pleased to be given the opportunity to publish Sabine E. R\u00e4disch’s blog article from Ecoquent-Positions<\/a>. Thank you very much, Sabine!<\/p>\n

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It shows up on our yearly energy bills and displays our heating energy consumption in numbers, but it remains for many a relatively abstract unit: the\u00a0kilowatt-hour<\/strong>. It is\u00a0the<\/em>\u00a0basic unit used in our energy blog. But honestly, who can explain off the cuff, what a kilowatt-hour is and in which scales it appears in the common household? I’m going to give it a shot.<\/p>\n

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Energy Is Electric Current and Heat \u2013 Among Other Things<\/strong><\/strong><\/h5>\n

In physics class I learned that energy is the ability to do work. Work in a physical sense can mean raising the temperature of the living room from 17 to 20 degrees, climbing a mountain or watching television \u2013 in which case the television actually does the work. Thus, electrical energy is consumed while we ourselves perhaps acquire energy in the form of potato chips. When it comes to food, the unit kilocalorie is still common. The official\u00a0SI unit of energy, however, is called a\u00a0joule, which is equal to one watt-second.<\/p>\n

\u00a0<\/strong><\/p>\n

1 Joule (J) = 1 Watt-second (Ws)<\/strong><\/strong><\/h5>\n

This is an extremely small unit. For example, a single heartbeat consumes about 1 joule. To go biking, rock climbing or to watch TV we need many times this amount of energy. To keep numbers easy to manage, so-called prefixes have been established, which increase a given unit by a factor of 1,000 \u2013 for example, k (kilo) for 1,000.<\/p>\n