A price ceiling of €87.50/MWh has been set in the auction, which will be concluded on 2 November.
The two technologies will compete directly against one another for the lowest cost of electricity, the agency confirmed.
Both solar and wind projects must be at least 750kW, according to auction rules.
Most solar projects are capped at 10MW, but may be 20MW in "some districts", the BNA stated, while no such limit is mentioned for onshore wind farms.
Federal Immission Control approvals must have been issued for wind projects three weeks before the bid date (11 October).
All participants must also factor in the cost of network and system integration into their bids.
Germany’s Renewable Energy Act (EEG) requires two joint onshore wind and solar auctions per year between 2018 and 2021.
This pilot phase will then be evaluated before the government decides whether to continue with the joint tenders beyond 2021.
The heads of the Federal Solar Industry Association (BSW-Solar) and the German Wind Energy Association (BWE) described the joint tender process as "unsuitable" for encouraging the build-out of the two technologies, following the auction in April.