From hydro-first to thermal-first: making thermal the base load (1955)

The question of what to build the base load on

The core of this shift was that TEPCO let go of its dependence on weather-driven hydropower under the twin pressures of surging demand and drought. That the company responsible for the largest block of demand in the country should be the one to lead in rewriting the industry’s common sense — “hydro-first, thermal-second” — into “thermal-first, hydro-second” can be read as an unavoidable choice in discharging its duty to keep the lights on. It was a decision to end, by swapping out the base-load source itself, the instability that slowed factory motors with every drought; and the new thermal technology introduced after the war gave that decision its economic footing.

Yet the turn from hydro to thermal was not the end of the question of what to generate with, but also its beginning. Thermal power took on a new variable — the price of fuel — and that instability later pushed the company toward nuclear power, and, in the search for buying power in fuel, toward merging the thermal business itself with another utility. The 1955 question of what to place the base load on runs, even after the nuclear accident, as an undercurrent beneath TEPCO’s supply structure — still being re-asked today.