| 摘要 |
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The aim of this report is to build up models which can be used to analyze the long term historical trend and future prospect of energy mix such as transition from coal to oil and then the increasing share of natural gas and the emergence of renewable energy. The model developed is characterized by (i) imperfect competition makes innovation profitable (ii) different energies are used as an intermediate inputs and the diversity of energy enhances overall productivity (iii) vintage-type model is applied in the energy sector in order to analyze the transition of energy mix, which has rarely been tried in the literature.
We developed two different models, analytical and empirical model. In analytical model, capital-vintage model of Mulder et al (2003) is modified into an energy-vintage model. In empirical model section, CGE(computable general equilibrium) model is developed to simulate the effect of climate change related regulations on the energy mix transition.
Main results of analytical model can be summarized as follows. Firstly, imposing an energy price tax under the assumption of an increasing capital intensity ratio of new vintage will promote the adoption of new vintage.
Secondly, if we assume the complementarity between different energies, an increase in the degree of the complementarity decreases the minimal demand required for vintage producers to operate profitably.
Therefore, it increases the equilibrium number of vintages sustained in the economy.
Thirdly, a higher degree of complementarity lowers the responsiveness of the relative demand for vintages to increases in productivity of newer vintages. As a result, diffusion of new vintages in the market slows down.
Fourthly, learning-by-using effect means that the most productive vintages are of an intermediate age and hence initial demand for newest vintage is relatively low. As a result, diffusion of new vintages in the market slows down.
For empirical analysis, we employ a CGE model describing world economy with 1985 of basis year. Compared with analytical model, detailed consideration is given to four energy sources, namely coal, oil, gas, and renewable energy.
Using numerical model, we investigate and compare changes in transition path from coal, oil, and gas to renewable energy due to imposing a tightened regulation on green house gas(GHG) emission and/or subsidy policy for enhancing renewable energy production.
Under the emission reduction scenario, GHG emission allowance is set 30% reduction against BaU scenario from the year 2008. Emission reduction raises monopoly rents from producing renewable energy than producing coal, oil, and gas with relatively higher carbon contents.
Therefore, consumption share and vintage of renewable energy will rise.
Under the subsidy scenario, government uses its revenue from auctioned emission permit to enhance investment on renewable energy.
In subsidy scenario, the vintage for renewable energy is longer and thus its productivity is higher because of learning by using effect than in emission reduction scenario. In terms of welfare and economic cost for reducing emission, subsidy scenario is much preferable to emission reduction scenario.
This report also shows that analyses which ignore vintage specification under monopolistically competitive market structure may have misleading policy recommendations.
Compared with results derived from model with vintage specification, the model without vintage specification tends to overestimate the economic cost of emission reduction but tends to underestimate consumption share of renewable energy.
106 pages. 38 refs., 28 figs., 19 tabs.
, Language: Korean |
