Economic effects and greenhouse gas emissions of small-scale hydropower projects in Japan: evidence from a 47-prefecture interregional input–output analysis

Abstract

This study investigates the economic effects (output, value added and employment) and greenhouse gas (GHG) emissions of small-scale hydropower [comprising construction and operation/maintenance (O&M) stages] using a 47-prefecture interregional input–output analysis. We evaluated both backward and income linkage effects using the Miyazawa model, and consequently demonstrated that: (1) with respect to output and employment, the backward linkage effects of the O&M stage are smaller than the construction stage, while the opposite is true for the income linkage effects. This may be mainly attributed to high value-added ratios of the O&M sectors, and implies relatively lower inputs and labor are required for running hydropower facilities than for constructing them. (2) Income linkage effects with respect to all the parameters are dispersed over several prefectures due partly to the income redistribution effect. (3) Analyses of life-cycle GHG emissions in physical terms reveal that the smaller the hydropower plant, the larger the GHG emissions per unit electricity production. This may be because more machinery must be used per unit electricity production at smaller plants, causing more emissions from both construction and maintenance works. (4) Assuming small-scale hydropower generation is conducted across 1602 sites in place of the general (including fossil fuel) power sector, Japan’s national GHG emissions are expected to be moderated by 0.145%, of which 55% is due to the technological effect and the remaining portion is through the electricity-saving effect from higher prices for small-scale hydropower.