Page 20 - Fundamentals of Ocean Renewable Energy Generating Electricity From The Sea

12 Fundamentals of Ocean Renewable Energy

fairly evenly distributed between Asia Pacific (where the largest reserves are
in China—12.8% of the world’s reserves), North America (where the largest
reserves are in the United States—26.6% of the world’s reserves), and Europe
and Eurasia. Although the numbers shown in the caption of Fig. 1.11 are
staggering (e.g. 187 trillion cubic metres of natural gas and 891,531 million
tonnes of coal), demand for these fossil fuel reserves is similarly staggering
(e.g. Fig. 1.6). At current rates of consumption, it is estimated that these fossil
fuel reserves will run out in [3]
● 114 years (coal)
● 53 years (natural gas)
● 51 years (oil)
The final figure is particularly worrying, as much of our modern transport needs
are governed by oil. However, there is clearly a strong case for replacing fossil
fuel power generating plants with low carbon (renewable) power stations long
before coal and natural gas reserves are depleted.
It can be clearly demonstrated that our reliance on fossil fuels is unsustain-
able by comparing the timescale of fossil fuel formation, and the estimated time
that they will be completely consumed by the human race. The age of the Earth
is around 4.5 billion years. The age of fossil fuels is in the range 150–650
million years, which is a significant timescale compared with the age of the
Earth. However, it is only in the last 300 years that human beings have started
exploiting fossil fuels using modern technologies, and at current rates they will
be completely consumed in about a century. Obviously, the age of the human
race, and particularly the industrial revolution, is almost zero compared with the
time for fossil fuels to form. By analogy, if you imagine the Earth as a person
aged 80 years, we can say that this person has made fossil fuels in 3 to 10 years.
The modern exploitation of fossil fuels would have begun in the last 3 min of
this person’s life, and the fossil fuels will be all used up in the next minute.
In conclusion, the Earth is not able to provide fossil fuel resources to
maintain the energy requirement of societies for future generations. Therefore,
sustainable development cannot be based solely on the fossil fuel industry, and
moving towards renewable energy technologies is the only way forward.

1.3 ELECTRICAL GRID SYSTEMS
The world’s first public power station, the ‘Edison Electric Light Station’, was
built in London in 1881. Power was generated by a steam engine, and a localized
grid system supplied electricity to neighbouring customers. Interestingly, this
early grid system supplied direct current (DC), in contrast to the alternating
current (AC) that is used today. This early power station produced 160 kW of
electricity, for lighting and running electric motors [8]. In the 1880s and 1890s, a
so-called ‘war of currents’ arose, with Thomas Edison backing low-voltage DC