By Giselda Vagnoni

ROME, Aug 22 (Reuters) - The Vatican will build a roughly €100 million ($117 million) renewable energy plant that could power the Holy See within two years via a system combining solar power and agriculture, sources involved in discussions on the project said.

The agrivoltaic plant is expected to have a capacity of 80 to 90 megawatts, making it one of Italy's largest such installations, the sources added. In such plants, solar panels are mounted several metres above the ground so crops can grow beneath them, with the shade helping to reduce evaporation and shielding plants from extreme weather.

A joint Italian-Vatican commission met earlier this month to launch the project at the Vatican-owned Santa Maria di Galeria estate on Rome's northwestern outskirts, after Italy ratified a 2025 bilateral agreement for development of the site this year. 

Officials disclosed no details of the project's cost, capacity or timeline after the meeting. The sources involved in the discussions said the plant could take 18 to 24 months to complete, including permitting and administrative procedures.

The Vatican did not immediately respond to a request for comment.

Vatican City, headquarters of the global Catholic Church and home to St. Peter's Basilica, is the world's smallest country, covering 108 acres and housing fewer than 900 residents.

The roughly 450-hectare Santa Maria di Galeria site, on Rome's northwestern outskirts, has hosted Vatican Radio's transmission facilities since the 1950s.

EXCESS ELECTRICITY WOULD BE SUPPLIED TO ITALY

The plant is designed to supply power to Vatican Radio's transmission station and help make Vatican City State fully energy self-sufficient.

The sources said the power could also be used by Holy See-linked properties including Rome's Bambino Gesù hospital.

The Vatican will not benefit from the financial incentives available to Italian households and businesses that install solar power. Any surplus electricity would be made available to Italy.

Tracking solar panels would cover about 200 hectares, nearly half the Santa Maria di Galeria site, one of the two sources said.

The project was a priority for the late Pope Francis, the first pontiff to accept the scientific consensus on climate change, and has been endorsed by Pope Leo XIV.

The bilateral agreement between Italy and Vatican City has extended to the agrivoltaic project the special status already granted to Vatican Radio facilities, including exemptions from Italian taxes and public charges.

Italy's ratification law states that the implementation of the agreement must not result in any new or additional burden on public finances.

Contracts for the work will be put out to tender in the coming weeks.

In 2008, under German-born Pope Benedict XVI, German companies SolarWorld and SMA Solar Technology donated the 2,400 photovoltaic panels and equipment installed on top of the Nervi Hall, which hosts papal audiences and concerts.

($1 = 0.8548 euros)

(Reporting by Giselda Vagnoni, additional reporting by Joshua McElwee; Editing by Hugh Lawson)

Find it fast

Looking for more insights? Explore our other news sections for updates on sustainable finance, companies and financial education