12.1 Introduction
After the industrial revolution in the eighteenth century, fossil fuels such as coal,
petroleum, and natural gas have been consumed globally as energy sources in a long
sequence of industrial and domestic activities. Extensive emissions of greenhouse
gases (GHG), such as CO 2 and freon, since the industrial revolution is a fundamental
cause of global warming and climate change (IPCC 2013, Ministry of Environment,
Japan 2018, Sakai and Amano 2008). Average annual surface temperatures have
increased by approximately 1
C since the eighteenth century. Thus, mitigation or
reduction of global warming is essential for the continued development of
humankind.
Energy resources such as fossil fuels are finite resources and do not allow
sustainable development. Nuclear power is a clean energy source because it does
not use fossil fuels, and CO 2 gas is not emitted during power generation. However, if
a critical accident occurs in a nuclear plant, extensive damage may occur over a wide
area, in the form of long-term radioactive contamination. Due to this risk, other
sources of energy that do not emit greenhouse gases must be explored.
Various natural sources of energy have been focused on in order to realize
sustainable development of industrial society. The most typical example is solar
energy, the technology for which has progressed rapidly. Wind energy, produced by
movement of air, is also common; electric power can be generated using various
types of windmill with no emissions of CO 2 . Conventional power generation by
water mill or water turbine also provides clean energy, because CO 2 is not emitted
during power generation. Novel technology for hydraulic power generation systems
is a candidate for clean energy.
Solar energy, wind energy, and water energy are typical examples of clean energy
that do not lead to emissions of greenhouse gases. Solar power plants have been
widely deployed with a range of generation capacities, allowing installation of
appropriate capacity according to individual requirements. This chapter presents
new types of power generation systems for wind and water energy. These new
technologies can be combined with solar energy plants to achieve hybrid use of
natural clean energy without GHG emissions.
12.2 Background
12.2.1 Variation in Energy Resources and Consumption
in Japan
Domestic annual energy consumption in Japan has varied since 1973, as shown in
Fig. 12.1 (Ministry of Economy, Trade and Industries, Japan 2019). Following the
Lehman crisis in 2008, total annual energy consumption clearly decreases, which
can be mainly attributed to the reduction in industrial energy consumption. This
216
T. Sakai et al.
After the industrial revolution in the eighteenth century, fossil fuels such as coal,
petroleum, and natural gas have been consumed globally as energy sources in a long
sequence of industrial and domestic activities. Extensive emissions of greenhouse
gases (GHG), such as CO 2 and freon, since the industrial revolution is a fundamental
cause of global warming and climate change (IPCC 2013, Ministry of Environment,
Japan 2018, Sakai and Amano 2008). Average annual surface temperatures have
increased by approximately 1
C since the eighteenth century. Thus, mitigation or
reduction of global warming is essential for the continued development of
humankind.
Energy resources such as fossil fuels are finite resources and do not allow
sustainable development. Nuclear power is a clean energy source because it does
not use fossil fuels, and CO 2 gas is not emitted during power generation. However, if
a critical accident occurs in a nuclear plant, extensive damage may occur over a wide
area, in the form of long-term radioactive contamination. Due to this risk, other
sources of energy that do not emit greenhouse gases must be explored.
Various natural sources of energy have been focused on in order to realize
sustainable development of industrial society. The most typical example is solar
energy, the technology for which has progressed rapidly. Wind energy, produced by
movement of air, is also common; electric power can be generated using various
types of windmill with no emissions of CO 2 . Conventional power generation by
water mill or water turbine also provides clean energy, because CO 2 is not emitted
during power generation. Novel technology for hydraulic power generation systems
is a candidate for clean energy.
Solar energy, wind energy, and water energy are typical examples of clean energy
that do not lead to emissions of greenhouse gases. Solar power plants have been
widely deployed with a range of generation capacities, allowing installation of
appropriate capacity according to individual requirements. This chapter presents
new types of power generation systems for wind and water energy. These new
technologies can be combined with solar energy plants to achieve hybrid use of
natural clean energy without GHG emissions.
12.2 Background
12.2.1 Variation in Energy Resources and Consumption
in Japan
Domestic annual energy consumption in Japan has varied since 1973, as shown in
Fig. 12.1 (Ministry of Economy, Trade and Industries, Japan 2019). Following the
Lehman crisis in 2008, total annual energy consumption clearly decreases, which
can be mainly attributed to the reduction in industrial energy consumption. This
216
T. Sakai et al.