The partnership will involve Glennmont and Emeren developing two stand-alone battery storage projects in the Campania region in southern Italy.
The projects are expected to start being built in late 2025 and begin operations in early 2027.
In common with other European countries, Italy needs to develop storage, including battery storage, to help store energy from variable renewable sources such as solar power.
Financial details of the transaction were not disclosed.
Glennmont Partners is owned by Nuveen, which manages $1.3 trillion in assets.