DFG
The Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) expects funded projects and researchers to publish research results in an open-access format. The call for open access publishing is laid down in the DFG's general usage guidelines.
With the applications for research projects at the DFG, you can raise a lump-sum payment up to a maximum of 750 Euro per year. These publication funds can be summed over the entire term of the funding (i.e., even beyond one year). Requested personnel and material resources from the same grant may also be used to finance Open Access publications, if required. However, the DFG does not fund applications for lump-sum payments independently of applications for research projects.
Further information can be found on the DFG's Open Access overview page.