Electricity from E.on's 200MW Colbeck's Corner site in Texas will be equal to 60% of Johnson & Johnson's total US power consumption.
Colbeck's Corner was completed in August 2016 and comprises 112 GE 1.7MW turbines. The deal will last 12 years. In July, data centre firm Digital Realty also signed a PPA for the project.
E.on has also started construction of its 278MW Radford's Run project (previously Twin Forks) in Illinois.
The $500 million project will use 139MW Vestas 2MW turbines and is set for completion in 2017. It will be Illinois' second largest project to date.
In a seperate development, E.on will also provide asset management and balance of plant servicing at Lincoln Clean Energy's 253MW Amazon Wind Farm in Texas.