Reducing the Energy Carbon Content - Energy and Climate: How to Achieve a Successful Energy Transition - page 70

In numerous applications, these energies cannot be directly substituted
for the fossil energies, whether to replace the fuels used in transport or to
produce energy upon request.
One solution tomeeting these requirements consists of using the energy
produced from biomass, as energy production from biomass can be
considered as carbon neutral.
Biomass stores energy in chemical form, like the fossil fuels, and can be
used in a boiler or to produce a biofuel used in an internal combustion
engine.
Capturing and storing CO 2 is also a way to achieve a zero carbon
balance. This option will be analysed in more detail in Chapter 8. In the
specific case of biomass, by capturing and storing CO 2 emitted during
combustion, it is even possible to achieve a net gain in the carbon balance.
It is thus possible to produce hydrogen or biofuels with negative carbon
content. Such an option is not currently used but might become attractive
in the future for improving the carbon balance.
Hydrogen generates energy by combustion without emitting CO 2 .
However, it requires an energy source to be produced. It is only an energy
vector and its interest in terms of carbon balance has to be evaluated by
considering all the stages from its initial production to its final use.
Development of new energy vectors, such as hydrogen, is a way of
promoting the use of alternative energies with zero or negative carbon
content, by extending the range of applications in which they can be
used.
Lastly, widespread penetration of these alternative energies cannot take
place without a significant increase in the number of energy storage
facilities, energy currently being stored by the fossil fuels.

Revival of nuclear energy

The share of nuclear energy in the worldwide energy balance is currently
limited due to its high technical requirements and the cost of the invest-
ments needed. In many countries, its development has been hindered by
generally adverse public opinion, in view of the inherent hazards. The rise
in the price of oil (and correspondingly of natural gas) creates a climate
which is much more favourable to the revival of nuclear energy.
Currently, all nuclear power stations use the energy released by fission
of heavy isotopes such as uranium 235 ( 235 U) 1 . After the first nuclear

1 Uranium 235 is a fissile isotope of uranium. Natural uranium deposits contain 0.7%

235.

U