Four in the Morning
The hour that tests a grid: no sun, low wind, low demand but not zero. What is actually running, and why that answer is the honest measure of a transition.
How Italy actually makes its electricity
Not the targets and not the press releases. The Alpine hydro that has run for a century, the Tuscan geothermal field that was first in the world, solar in the south, wind on the ridges, the coal stations closing — and what is actually turning at four in the morning.
How to read this
Blue marks anything measured. Red marks anything ending. Where a figure is unpublished the column stays empty rather than being filled.
The first commercial geothermal station in the world opened on this ground. The field is still on the network.Photo: Larderello 002.JPG · Wikimedia Commons
Geothermal · The field that was first
Larderello Was First
The Tuscan field where geothermal electricity was generated before anywhere else, and why the geology there permits it. What a dry-steam field is, how the wells are managed, and why this technology stayed regional rather than spreading.
Seven things make the electricity
At four in the morning, in the right-hand column
| No. | Source | What it is, physically | At 04:00 |
|---|---|---|---|
| 01 | Gas | The combined-cycle fleet, following demand hour by hour. | Held on, part load |
| 02 | Hydro | Alpine reservoirs, run-of-river, and pumped storage. | Pumping |
| 03 | Geothermal | Southern Tuscany only. Around 900 MW, roughly 6,000 GWh a year. | Flat |
| 04 | Solar | Ground-mount in the south, and rooftop in its thousands. | Zero |
| 05 | Wind | Ridges and coastal plain south of Rome, and both islands. | Weather |
| 06 | Coal | A closure programme with a date attached; Sardinia later. | Phase-out |
| 07 | Imports | Across the Alpine border, scheduled and priced hourly. | Importing |
Sicily and Sardinia: Grids at the End of a Wire
Island systems with their own constraints and their own cables to the mainland — the clearest illustration of what a network is for.
Where the machines are
Filed by source, plotted on the country
- LarderelloGeothermal — the Tuscan dry-steam field
- BrindisiCoal — a mainland station on the phase-out list
- Sardinia windWind, and an island on the end of one cable
- Alpine hydroHydro — reservoirs, penstocks and pumped storage
- Sicily solarSolar, and a second island system
- MilanDemand — the load the north–south network has to reach
Point at a row to find it on the map. A reader can see which regions carry which generation, and the stations on the closure list sit on the same map as what is replacing them.
04:00
What is running when the sun is down
Gas, at part load
Grids, operators and research bodies whose interest in how Italy generates, balances and delivers power runs as deep as ours.
Water, held or pumping
Run-of-river keeps going because the river does. Reservoir and pumped storage are mostly buying the trough, lifting water uphill to sell it back at the evening peak.
Geothermal, flat
The Tuscan fields run at close to full output around the clock, indifferent to the weather and to the hour.
Imports, over the Alps
A scheduled quantity arriving across the border, carrying whatever the difference turns out to be.