Larderello is the oldest geothermal field in operation worldwide. The first
experiment for electricity production was carried out in 1904, and this field has
represented the sole example in the world of intensive geothermal energy exploitation
up to the end of 50’s, when geothermal power plants were commissioned and started up
in New Zealand and then in USA.
After a first period of intensive field development and electricity generation
increase, in the mid 70’s serious problems of production decline became evident and
new R&D programs were implemented to sustain/increase the steam production.
A deep exploration program was implemented and it made possible to verify the
presence of productive layers up to depths of 3,000-4,000m, with an increase of
temperature and pressure with depth. On the basis of the positive results several
deep wells have been drilled and a reassessment of the geothermal resource was
carried out, in terms volumes of rocks characterized by thermal anomaly and heat in
place.
In the same period a program of experiments related to low permeability wells
stimulation and reinjection was implemented with the specific aim of developing a
“heat mining strategy”, that is the same strategy for EGS.
The results of both the programs have been very successful and have made it possible
to sustain/increase the steam production of the area.
More in particular on the basis of the positive results of well stimulation and water
injection activities, new exploitation strategies have been adopted for the
Larderello field, aimed at the resource sustainability. In these recent years the
exploitation strategies have been therefore moved from those typical of hydrothermal
systems to those related to Enhanced Geothermal Systems.

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