Production at Rusnano's plant in Rostov will start by the end of the current year, the companies said.
According to Alisher Kalanov, head of Rusnano's department of perspective projects in the fuel and energy unit, Rusnano will invest around RUB 1 billion ($18 million) by 2024 in the project.
A further RUB 2 billion (€28 million) will be provided by Windar Renovables.
The project will be implemented on the basis of a joint venture, a controlling stake in which will be held by the Spanish company.
This is the second large-scale wind-power contract signed by Rusnano in recent months.
In February, the company signed a contract with Vestas' Russian subsidiary to establish a blade production facility in the Ulyanovsk region, south-west Russia. The volume of investments is set to be RUB 1.4 billion.
In November 2017, Dutch turbine manufacturer Lagerwey, since taken over by Enercon, entrered a joint venture with Rusnano to set up turbine production factory in the country, as part of a licensing agreement with the Russian firm.