Page 19 - Fundamentals of Ocean Renewable Energy Generating Electricity From The Sea

Introduction Chapter | 1 11

FIG. 1.10 Time series of the carbon dioxide concentration in the atmosphere for a period of
800,000 years based on the ice cores at Dome C in Antarctica. The current concentration of carbon
dioxide is above 400 ppm. (The data have been extracted from the NOAA database.)

that this would significantly reduce the risks and impacts of climate change.
Clearly, one important step, perhaps the most important step, is to reduce the
CO 2 that is emitted by electricity generation, that is, by thermal power plants
that rely on the combustion of fossil fuels. However, sustainable power plants
that are based on renewable ‘fuels’ such as wind, solar, hydro, and marine will
require considerable investment and changes in lifestyle (e.g. increased cost
to the consumer, or possibly changes in patterns of consumption), and poses
significant challenges, such as variability in the electricity that is generated
from renewables, grid integration, and storage. Some of these challenges are
introduced in Section 1.3.

Fossil Fuel Reserves
As if global warming was not enough of an incentive to seek low carbon
(renewable) sources of electricity generation, the other major reason is the finite
nature of fossil fuel reserves. The geographical distribution of estimated oil,
coal, and natural gas reserves is plotted in Fig. 1.11, with the actual values
cited in the figure caption. Around half of the world’s oil reserves are in the
Middle East (Fig. 1.11A). However, the fossil fuels that are currently used for
significant levels of electricity generation around the world are coal and natural
gas (Fig. 1.5). Although the Middle East contains large reserves of natural gas,
Europe and Eurasia contains almost one-third of the world’s reserves, with a
much lower proportion (7%) in North America. However, coal reserves are