targets and scenarios have been promoted by several countries. Reduction of net
CO 2 emissions by 2050 to 50% of current levels has been recognized as a global
goal. With this in mind, countries such as the United Kingdom and Japan have
announced national goals and pathways to achieve them (Fujino et al. 2008; Kevin
et al. 2008; NIES 2008; Sarah et al. 2008). To allow clearer elucidation of a realistic
long-term vision and contribute to international climate negotiations in the postKyoto period, mid-term targets for 2020 have been proposed by the United States,
the United Kingdom, Germany, France, and Japan. These countries seek to reduce
their CO 2 emissions by 7, 26, 40, 20, and 25%, respectively, from 1990 levels.
As the main source of CO 2 emissions, energy systems feature heavily in the
mid-term and long-term pathways mentioned above. Thus, the development of a
low-carbon energy system, through penetration of energy efficiency and utilization
of renewable energy sources, will play a key role in achieving a low-carbon society.
While global coordination is necessary to understand the macro level, local
actions cannot be neglected if policies are to be effective. In order to realize a
low-carbon society at the local level, regional characteristics (e.g., natural resources,
climate conditions) must be accounted for. To achieve the same low-carbon goal,
different regions may require different configurations of technologies, institutions,
and lifestyle changes. Many local municipalities have unveiled climate change
mitigation goals and plans for the mid- to long-term. Since April 2008, 13 cities in
Japan with varying local conditions have been selected as Environmental Model
Cities, functioning as pilot demonstrations of actions that could be taken to achieve
low-carbon development.
Although an integrated action plan has been promoted in many cities, the two
main components of a municipality (urban and rural areas) are always treated
separately, especially with respect to energy systems. Urban areas usually have
higher energy demand density than rural areas; the latter are dominated by residential
demands. From the supply side, energy infrastructure is well maintained and can be
extensively enhanced in urban areas, while in rural areas renewable energies including biomass, wind, and solar energy may be enriched.
According to this analysis of the characteristics of urban and rural areas in terms
of both supply and demand, feasible technical options are proposed for various types
of users (residential, commercial, industrial) in both areas, as shown in Table 5.1.
Most currently available high-efficiency thermal power generation and renewable
technologies have been considered in the context of developing a low-carbon society
through innovation of local energy systems. For residential customers, solar heaters,
photovoltaic (PV) systems, micro combined heat and power (micro CHP) plants, and
micro wind turbines are preferred. For industrial customers, because of high energy
requirements, large-scale CHP plants and biomass energy systems are suitable. For
the same type of end-user, urban and rural areas may introduce different technologies because of differences in energy stock and infrastructure as described above.
Figure 5.1 shows the concept of a local energy system based on urban-rural
cooperation. Regional circulation of energy and resources (e.g., biomass) allows
development a systematic partnership between urban and rural areas. Rural areas
have abundant renewable energy resources, while urban areas are centers of energy
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H. Ren et al.
CO 2 emissions by 2050 to 50% of current levels has been recognized as a global
goal. With this in mind, countries such as the United Kingdom and Japan have
announced national goals and pathways to achieve them (Fujino et al. 2008; Kevin
et al. 2008; NIES 2008; Sarah et al. 2008). To allow clearer elucidation of a realistic
long-term vision and contribute to international climate negotiations in the postKyoto period, mid-term targets for 2020 have been proposed by the United States,
the United Kingdom, Germany, France, and Japan. These countries seek to reduce
their CO 2 emissions by 7, 26, 40, 20, and 25%, respectively, from 1990 levels.
As the main source of CO 2 emissions, energy systems feature heavily in the
mid-term and long-term pathways mentioned above. Thus, the development of a
low-carbon energy system, through penetration of energy efficiency and utilization
of renewable energy sources, will play a key role in achieving a low-carbon society.
While global coordination is necessary to understand the macro level, local
actions cannot be neglected if policies are to be effective. In order to realize a
low-carbon society at the local level, regional characteristics (e.g., natural resources,
climate conditions) must be accounted for. To achieve the same low-carbon goal,
different regions may require different configurations of technologies, institutions,
and lifestyle changes. Many local municipalities have unveiled climate change
mitigation goals and plans for the mid- to long-term. Since April 2008, 13 cities in
Japan with varying local conditions have been selected as Environmental Model
Cities, functioning as pilot demonstrations of actions that could be taken to achieve
low-carbon development.
Although an integrated action plan has been promoted in many cities, the two
main components of a municipality (urban and rural areas) are always treated
separately, especially with respect to energy systems. Urban areas usually have
higher energy demand density than rural areas; the latter are dominated by residential
demands. From the supply side, energy infrastructure is well maintained and can be
extensively enhanced in urban areas, while in rural areas renewable energies including biomass, wind, and solar energy may be enriched.
According to this analysis of the characteristics of urban and rural areas in terms
of both supply and demand, feasible technical options are proposed for various types
of users (residential, commercial, industrial) in both areas, as shown in Table 5.1.
Most currently available high-efficiency thermal power generation and renewable
technologies have been considered in the context of developing a low-carbon society
through innovation of local energy systems. For residential customers, solar heaters,
photovoltaic (PV) systems, micro combined heat and power (micro CHP) plants, and
micro wind turbines are preferred. For industrial customers, because of high energy
requirements, large-scale CHP plants and biomass energy systems are suitable. For
the same type of end-user, urban and rural areas may introduce different technologies because of differences in energy stock and infrastructure as described above.
Figure 5.1 shows the concept of a local energy system based on urban-rural
cooperation. Regional circulation of energy and resources (e.g., biomass) allows
development a systematic partnership between urban and rural areas. Rural areas
have abundant renewable energy resources, while urban areas are centers of energy
106
H. Ren et al.