Page 9 - Fundamentals of Ocean Renewable Energy Generating Electricity From The Sea

Chapter 1

Introduction

There has been a considerable increase in global electricity consumption over
the last few decades, yet with vast differences between countries and regions. In
addition, the global energy mix has changed significantly over time—the world
still relies on coal for over 40% of its electricity generation, but the amount of
electricity that is generated from renewable sources has risen rapidly over the
last decade.
In this chapter, we introduce the global energy mix and demonstrate how
electricity consumption per capita is linked to quality of life. We discuss the
pressures of climate change, and dwindling fossil fuel reserves, and how these
two issues are driving the transition towards low carbon renewable sources of
energy. However, renewable energy generation presents a challenge to electrical
grid systems, and we discuss the challenges of accommodating a high penetra-
tion of renewable energy into existing grid infrastructure. Finally, we introduce
the topic of marine energy and the fundamental concepts of energy and power.

1.1 THE GLOBAL ENERGY MIX
Global electricity production was 23,950 TWh in 2015 (Fig. 1.1), which, with
a world population of 7.35 billion, translates as an annual power output of
3.3 MWh per capita (Fig. 1.2). Electricity generation has doubled since 1990,
when global production was 11,854 TWh, representing an annual power output
1
of 2.3 MWh per capita. Energy consumption is one of the most accurate
indicators of wealth, and so more affluent countries will generally have a higher
electric power consumption per capita (Table 1.1). For example, it is fairly
striking to note from this table that the United States, with an electricity usage
of 12,988 kWh per capita in 2013, has 17 times the electricity consumption (per
capita) as India (765 kWh per capita). The Human Development Index (HDI)
is a summary measure of average achievement in key dimensions of human
development: a long and healthy life, being knowledgeable, and having a good
standard of living [1]. The HDI is the geometric mean of normalized indices for
each of the three dimensions. The trend of electricity consumption per capita
against HDI is very clear (Fig. 1.3). Noting that the x-axis in this figure is
logarithmic, Norway tops Iceland (in contrast to Table 1.1) for HDI, despite

1. Global population was 5.28 billion in 1990 (http://data.worldbank.org).
Fundamentals of Ocean Renewable Energy. https://doi.org/10.1016/B978-0-12-810448-4.00001-X
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