80 T. WAKIYAMA ET AL.
(Mizumoto et al. 2013 ; Ishikawa et al. 2012 ; NISTEP 2013). Such studies
can help individuals realize the economic and environmental benefi ts of
expanding renewable energy resources. To assess the effects of renewable
energy investment, energy generation systems should be disaggregated into
different renewable energy components, as a regular input–output table
does not contain detailed information on renewable energy options in the
electricity generation and electricity construction sectors. For instance,
through an assessment of the effects of renewable energy investment on
GDP and CO 2 emissions, Mizumoto et al. ( 2013 ) estimate production
inducement in the solar cell sector to reach 87.6 billion JPY (2.09 produc-
tion inducement coeffi cient) and production inducement amounts in
balanced systems to increase to 45.5 billion JPY (2.02 production induce-
ment coeffi cient) via investments in 10 MW-scale solar PV systems. This
study also shows that if Japan were to import 30% of all solar cells within the
PV system, the total social value-added amount would be negative (e.g.,
−0.8 JPY/kWh of net value added). Conversely, with regard to impacts on
CO 2 emissions, the value-added cost of reducing CO 2 emissions amounts
to approximately 20.5 thousand JPY per tCO 2 of 10 MW solar PV along-
side of 139.1 g-CO 2 /kWh emissions within the lifecycle of PV system
production.
Some studies compare the economic impacts of renewable energy
before and after the occurrence of exogenous shocks or policy interven-
tions. Ishikawa et al. ( 2012 ) assessed the regional recovery and economic
effects of reducing CO 2 emissions by introducing solar PV and wind
power generation to the Tohoku area as a replacement for nuclear power
generation after the Fukushima accident using various scenarios. Other
studies have examined the effects of renewable energy investments in
different countries (IEA 2014 ; Caldes et al. 2009 ).
However, these studies have largely been conducted at the national
level rather than at the city level, which is attributable to the fact that
city- level analyses are diffi cult to conduct because of insuffi cient data
sources and a lack of input–output tables available for many cities.
However, as noted in Sect. 5.1 , renewable energy is expected to have local
effects by generating energy and boosting local production.
5.2.2 Renewable Energy Policies and Investment
in Yokohama, JapanTo increase installation rates and the dissemination of renewable energy,
policies that promote renewable energy is an important instrument.