An early method of high-voltage direct current…

An early method of high-voltage direct current (HVDC) transmission, as developed by the Swiss engineer René Thury, is implemented commercially in Italy by the Acquedotto de Ferrari-Galliera Company in 1889.

This system transmits 630 kW at 14 kV DC over a distance of one hundred and twenty kilometers (seventy-five miles).

Earlier, the company had built a water supply for Genoa from the Gorzente River, and were interested whether turbines for electrical generation might address their long standing problem of reducing excess pressure.

The first turbine of 140 hp (100 kW) is installed at Galvani station, which turns the two Thury 6-pole dynamos that each produce 1000 to 1100 volts at 45 amperes.

In order to keep the same current, their speed varies from 20 to 475 rpm, regulated by changing the flow through the water turbine.

The circuit supplies fifteen motors along the line stretching to Genoa, including a 60 hp (44 kW) motor at the railway station, and motor transformers at Central Electric Lighting Station in Genoa.

Additional generation plants followed providing lighting as well as motive power to a number of mills, factories and railway repair shops.