Enertrag said the wind projects, located across the country, are at various stages of development, including some that are close to construction.
The German firm said the power from wind projects in South Africa costs around 40% less than conventional generation.
"Our South African partner GEED is one of the most successful companies in the field of renewable energies. Over 500MW of realised project developments speaks volumes," Enertrag CFO Gunar Hering said.
"By participating in the 1.8GW pipeline, we have taken a significant step towards becoming a global energy company.
"The planning expertise of Enertrag complements the convincing regional knowledge and anchoring of GEED," Hering added.
Earlier this month, 27 long-delayed power purchase agreements with renewable energy projects in South Africa were signed by state-utility Eskom.
Deals for 1.4GW of wind capacity were completed, after nearly two years of inaction.
According to its website, GEED has previously worked alongside Irish developer Mainstream Renewable Power at the 138MW Jeffery’s Bay, 140MW Loeriesfontein, 140MW Khobab and 80MW Noupoort projects in South Africa.