CERNUSCO SUL NAVIGLIO, Italy, June 11 (Reuters) - I ndustrie De Nora began construction of Italy's largest electrolyser manufacturing plant on Tuesday to meet expected demand growth for green hydrogen, which forms part of the EU's plans to replace fossil fuels in energy intensive industries.

Green hydrogen, which is produced by splitting water through electrolysis, is also seen by some as a potential solution to the problem of storing excess renewable power such as solar or wind.

The European Union aims to produce 10 million metric tons and import 10 million tons of green hydrogen by 2030 in a bid to replace fossil fuels, which emit carbon dioxide when burned, contributing to climate change.

De Nora Chief Executive Paolo Dellacha said at an event to mark the start of building works on the new factory that the group already had orders to sell electrolysers able to produce hydrogen with a capacity of 2 gigawatts (GW).

This is equal to the annual production capacity of the plant, which will cost around 100 million euros ($107 million). It will benefit from up to 63 million euros in public grants as it is considered strategic at a national and EU level.

It is due to be ready at the end of 2025 or early in 2026.

"Estimates over the future need for electrolysers vary a lot and experts now say Europe could need capacity of 100 GW or more by 2030... these figures make us hope for a very significant growth potential," Dellacha said at the event.

A joint venture between Saudi Arabia Acwa Power and Air Products to build NEOM Green Hydrogen Project is among De Nora's customers for electrolysers, he said.

Meanwhile, Italy, Germany and Austria in May signed an agreement to cooperate on developing a network to transport hydrogen from the southern Mediterranean to northern Europe.

A group of companies including Italian gas grid operator Snam has teamed up to build the SoutH2 pipeline by the beginning of the next decade, with a financial commitment of more than 4 billion euros.

Snam CEO Stefano Venier said on the sidelines of Tuesday's event that group is "very satisfied with its stake in De Nora".

Snam owns nearly 22% in De Nora, having sold part of its initial stake after the group became public. ($1 = 0.9314 euros) (Reporting by Francesca Landini, editing by Cristina Carlevaro and Alexander Smith)