“…15 For transmission, a high-voltage direct current (HVDC) line is superior to an alternating current line at distances of interest for this study (X750 km). Costs varied with transmission voltage V TL , rated transmission power P TL , transmission length D TL , and some other minor parameters, using equations fitted to data in Hauth et al (1997); see Tables 1 and 2. The model optimum used voltages of (EPRI, 1993) with the following assumptions: construction period 2.5 years (3 equal payments), inflation rate 2%/yr, book life 30 years, tax life 20 years, modified accelerated capital recovery system (MACRS) depreciation for tax purposes, corporate tax rate 38.2%, property taxes and insurance 2%/yr, nominal return on equity 10%/yr, nominal return on debt 6.5%/yr, equity/debt share 45%/55%, real discount rate 5%/yr (after-tax weighted real average cost of capital).…”