  Universities and research centers in Spain are subject to a national open
access (OA) mandate and to their own OA institutional policies, if any, but
compliance with these requirements has not been fully monitored yet. We studied
the degree of OA archiving of publications of 28 universities within the period
2012-2014. Of these, 12 have an institutional OA mandate, 9 do not require but
request or encourage OA of scholarly outputs, and 7 do not have a formal OA
statement but are well known for their support of the OA movement. The
potential OA rate was calculated according to the publisher open access
policies indicated in Sherpa/Romeo directory. The universities showed an
asymmetric distribution of 1% to 63% of articles archived in repositories that
matched those indexed by the Web of Science in the same period, of which 1% to
35% were OA and the rest were closed access. For articles on work carried out
with public funding and subject to the Spanish Science law, the percentage was
similar or slightly higher. However, the analysis of potential OA showed that
the figure could have reached 80% in some cases. This means that the real
proportion of articles in OA is far below what it could potentially be.
