In this section, an energy scenario will be described for the years 2025
and 2050 based on . The objective is to show the potential that renewable
technologies have not only to meet the mitigation targets but also the
technological and economical expectations.
One way to gain perspective
on the current situation is to construct scenarios that shed some light
on the various possibilities and their implications. The scenarios presented
here focus especially on the technological option.
The IPCC developed
several scenarios [49,50]. The one adopted here is the scenario characterised
by "high economic growth" and "accelerated policies"
and is called the renewable-intensive scenario. This scenario was designated
to represent the adoption of energy efficient policies without restricting
economic growth. It projects a doubling of world population and an eighth-fold
increase I gross world economic product between 1985 and 2050. Economic
growth is assumed to be higher for developing countries than for those
This scenario assumes
that renewable energy technologies will capture markets whenever a plausible
case can be made that renewable energy is no more expensive on a life-cycle
cost basis than conventional alternatives and their use at the level indicated
will not create significant environmental, land use, or other problems
The key points in building the scenario are:
There would be a diversity of energy sources, the relative
abundance of which would vary from region to region. Various combinations
of hydroelectric, intermittent renewable power sources (wind, solar-thermal,
and photoelectric power), biomass power and geothermal power could provide
electricity. Fuels could be provided by methanol, ethanol, hydrogen and
methane derived from biomass, supplemented by hydrogen derived electrolitically
from intermittent renewables.
Emphasis would be given to the efficient use of both renewable
and conventional energy supplies, in all sectors. Emphasis on efficient
energy use facilitates the introduction of energy carriers such as methanol
and hydrogen. It also makes it possible to extract more useful energy
from such renewable resources as hydropower and biomass, which are limited
by environmental and land use constraints.
Biomass would be widely used. Biomass would be grown widely
and converted efficiently to electricity as well as liquid and gaseous
fuels, using modern technology, in contrast to the present situation,
where biomass is used inefficiently and sometimes contributes to deforestation.
Intermittent renewables would provide as much as one third
of the total requirements cost-effectively in most regions, without the
need for new electrical storage technology.
Natural gas would play a major role supporting the growth
of a renewable energy industry. Natural; gas-fired turbines, which have
low capital costs and can quickly adjust their electrical output, can
provide excellent backup for intermittent renewables on electric power
grids. Natural gas would also help launch a biomass-based methanol industry.
Methanol might well be introduced using natural gas feedstocks before
the shift to methanol derived from biomass occurs.
A renewable-intensive energy future would introduce new
choices and competition in energy markets. Growing trade in renewable
fuels and natural gas would diversify the mix of suppliers and the products
traded, which would increase competition and reduce the likelihood of
rapid price fluctuations and supply disruptions. It could lead also to
a stabilisation of energy prices.
Most electricity produced from renewable sources would be
fed into large electrical grids and marketed by electricity utilities.
Liquid and gaseous fuels would be marketed as much as oil
and natural gas are today. Large oil companies could become the principal
marketers; some might become producers, perhaps in joint ventures with
agricultural and forest-product industry firms.
In what follows, different hypotheses of energy resources and energy use
to the year 2050 will be described. These assumptions will model the scenario
that will be described at the end of the section.