1.3.2
We just have seen that solar energy can be converted into electricity, heat and
chemical energy. The Sun is the energy source for almost all the processes happening on
the surface of our planet: wind is a result of temperature difference in the atmosphere
induced by solar irradiation; waves are generated by the wind; clouds and rain are initially
formed by the evaporation of water due to sunlight. As the Sun is the only real energy
source we have, we need to move to an era in which we start to utilize the energy provided
by the sun directly for satisfying our energy needs. The aim of this book is to teach the
reader how solar energy can be utilized directly.
Electricity
As we see in Figure 1.5 (a), 17% of all the world’s final energy is used as electricity,
which is a form of energy that can be easily and cheaply transported with relatively small
losses through an electric grid. It is important to realize that without electricity modern
society as we know it would not be possible. Electricity has been practically used for more
than 100 years now. It provides us the energy to cook food, wash, do the laundry,
illuminate buildings and streets, and for countless other applications. The access to
electricity strongly determines our living standard. Despite this importance of electricity,
in 2009 still about 1.3 billion people had no access to electricity.
As we see in Figure 1.5 (b), about 67% of the electricity is generated using fossil
fuels, where coal is the dominant contributor. As coal emits about twice as much CO 2 per
generated kWh as natural gas, coal power plants are a major contributor to global
warming. Nuclear is responsible for 12% of the World’s electricity generation. With 16%,
hydroelectricity is by far the largest contributor among the renewable energy sources.
Figure 1.5: (a) The final energy consumption by energy service [13] and (b) the energy carriers used for electricity
generation [14] ( © OECD/IEA 2012, Insights Series 2012: Policies for renewable heat, IEA Publishing. Licence:
www.iea.org/t&c/termsandconditions).
Of all the generated electricity, about 40% is used for residential purposes and 47% is
used by industry. 13% is lost in transmission. In 2007, transport did not play a significant
role in the electricity consumption. However, this is expected to change as electric cars
We just have seen that solar energy can be converted into electricity, heat and
chemical energy. The Sun is the energy source for almost all the processes happening on
the surface of our planet: wind is a result of temperature difference in the atmosphere
induced by solar irradiation; waves are generated by the wind; clouds and rain are initially
formed by the evaporation of water due to sunlight. As the Sun is the only real energy
source we have, we need to move to an era in which we start to utilize the energy provided
by the sun directly for satisfying our energy needs. The aim of this book is to teach the
reader how solar energy can be utilized directly.
Electricity
As we see in Figure 1.5 (a), 17% of all the world’s final energy is used as electricity,
which is a form of energy that can be easily and cheaply transported with relatively small
losses through an electric grid. It is important to realize that without electricity modern
society as we know it would not be possible. Electricity has been practically used for more
than 100 years now. It provides us the energy to cook food, wash, do the laundry,
illuminate buildings and streets, and for countless other applications. The access to
electricity strongly determines our living standard. Despite this importance of electricity,
in 2009 still about 1.3 billion people had no access to electricity.
As we see in Figure 1.5 (b), about 67% of the electricity is generated using fossil
fuels, where coal is the dominant contributor. As coal emits about twice as much CO 2 per
generated kWh as natural gas, coal power plants are a major contributor to global
warming. Nuclear is responsible for 12% of the World’s electricity generation. With 16%,
hydroelectricity is by far the largest contributor among the renewable energy sources.
Figure 1.5: (a) The final energy consumption by energy service [13] and (b) the energy carriers used for electricity
generation [14] ( © OECD/IEA 2012, Insights Series 2012: Policies for renewable heat, IEA Publishing. Licence:
www.iea.org/t&c/termsandconditions).
Of all the generated electricity, about 40% is used for residential purposes and 47% is
used by industry. 13% is lost in transmission. In 2007, transport did not play a significant
role in the electricity consumption. However, this is expected to change as electric cars