| Abstract: |
This article investigates the technological knowledge pattern underlying the
recent evolution in ocean energy technology (OET) trajectories, especially
tidal and wave energy, ocean thermal energy, salinity gradient energy and
offshore wind energy. Examination of the relational properties among the
knowledge elements in the OET knowledge base, in particular, their
substitutability and complementarity, allows a better understanding of the
coherence of this knowledge base and the technological trajectories within the
sector. We use patent data extracted from the Questel ORBIT database. The
various technical options related to OETs are identified by Cooperative Patent
Classification (CPC) codes and enable the construction of a dataset of OET
patents granted between 2000 and 2015. We analyze the main trends emerging
from the patent statistics and we construct a network of citations among OET
patents and apply to it a main path algorithm. This allows a mapping of all
possible streams of cumulative growth of technological knowledge and
identification of the most important ones. We show that the knowledge base of
OETs is split into two main families and technology patterns depending on
whether the harnessing of ocean power and its conversion to renewable
low-carbon electricity derive from physical or chemical science. OET
trajectories are somewhat compartmentalized with few connections amongst them;
however, there are links between some pivotal tidal and wave energy and
offshore wind energy patents which have become the foundations to an OET
knowledge base. By focusing specifically on the physics-based family of OETs,
we can investigate the structural aspects of this knowledge base and analyze
the aggregate level of complementarity and substitutability of its knowledge
constituent. Our analysis partly confirms the increased coherence of the OET
knowledge base over time but also highlights its fluctuating nature which in
some ways mirrors the intermittent nature of ocean energy funding, further
slowing consensus over designs which is key to commercialization. |