The Economic Competitiveness of Renewable Energy: Pathways to 100% Global Coverage

Chapter 2

Analysis of Today’s Energy Situation

2.1 Basic Energy Terms

Energy, measured in Joule [J], is the product of power, measured in Watts [W], multiplied by time, measured in seconds [s]. In technical terms, it is convenient to measure time in this context not in seconds, but in hours (Wh, which is 3,600 Ws = 3,600 J). Through using a prefix as shown in Table 2.1, the huge span of different energy contents can be described. The table also shows the prefixes for small dimensions, often used for length (measured in meters, m), weight (measured in grams, g) and time (measured in seconds, s, also needed in later sections). Except for the very first and the last interval there is always a factor of 1,000 separating the various prefixes. Starting from the unit, each prefix for smaller numbers is one thousand’s of the preceding: 1 milli = 1/1,000 unit, 1 micro= 1/1,000 milli and so on. Similarly, for increasing numbers, each following prefix is 1,000 times larger than the preceding one: 1 kilo = 1,000 units, 1 Mega = 1,000 kilo and so on. In order to have a better feeling for the huge span ranging from 10⁻³⁵ up to 10³⁰ which covers 65 orders of magnitudes some examples are given in terms of length. Although this exercise is trivial for scientists it may be helpful for others.

Table 2.1 Prefixes for (very) large and (very) small numbers, the scientific notion (in brackets the logarithm) together with some examples.

While the smallest dimensions equal the subcomponents of the constituents ...