System comprising - a high temperature electrolyser, - a first supply line of the electrolyser configured to supply steam to the electrolyser, - a first electrolyser discharge line configured to discharge dihydrogen from the electrolyser, - a second electrolyser discharge line configured to discharge dioxygen from the electrolyser, - a first heat exchange module configured to provide heat exchange between the first steam supply line and the first dihydrogen discharge line, - a steam generator arranged on the first steam supply line, upstream of the first heat exchange module, and configured to produce steam from liquid water, characterised in that the system comprises a module for recovering the thermal energy of dihydrogen at the output of the first heat exchange module for the benefit of the first steam supply line, the recovery module comprising: o a compressor arranged on the first dihydrogen discharge line, downstream of the first heat exchange module, and configured to compress the dihydrogen, o a first heat exchanger arranged between the first steam supply line, upstream of the steam generator, and the first dihydrogen discharge line, downstream of the compressor, so as to transmit the thermal energy of the compressed dihydrogen to the liquid water, upstream of steam generator, and that the system comprises a second electrolyser supply line configured to supply air to the electrolyser and a third heat exchanger arranged between the first dihydrogen discharge line, downstream of the first heat exchanger of the energy recovery module, and the second air supply line. - a high temperature electrolyser, - a first supply line of the electrolyser configured to supply steam to the electrolyser, - a first electrolyser discharge line configured to discharge dihydrogen from the electrolyser, - a second electrolyser discharge line configured to discharge dioxygen from the electrolyser, - a first heat exchange module configured to provide heat exchange between the first steam supply line and the first dihydrogen discharge line, - a steam generator arranged on the first steam supply line, upstream of the first heat exchange module, and configured to produce steam from liquid water, characterised in that the system comprises a module for recovering the thermal energy of dihydrogen at the output of the first heat exchange module for the benefit of the first steam supply line, the recovery module comprising: o a compressor arranged on the first dihydrogen discharge line, downstream of the first heat exchange module, and configured to compress the dihydrogen, o a first heat exchanger arranged between the first steam supply line, upstream of the steam generator, and the first dihydrogen discharge line, downstream of the compressor, so as to transmit the thermal energy of the compressed dihydrogen to the liquid water, upstream of steam generator, o a compressor arranged on the first dihydrogen discharge line, downstream of the first heat exchange module, and configured to compress the dihydrogen, o a first heat exchanger arranged between the first steam supply line, upstream of the steam generator, and the first dihydrogen discharge line, downstream of the compressor, so as to transmit the thermal energy of the compressed dihydrogen to the liquid water, upstream of steam generator, and that the system comprises a second electrolyser supply line configured to supply air to the electrolyser and a third heat exchanger arranged between the first dihydrogen discharge line, downstream of the first heat exchanger of the energy recovery module, and the second air supply line.