Page 309 - Fundamentals of Ocean Renewable Energy Generating Electricity From The Sea

294 Fundamentals of Ocean Renewable Energy

In addition to leasing of a site, required permits for construction, operation,
and maintenance of a project should be applied and issued. Permitting is often
integrated into marine spatial planning, because it involves close interactions
with local and governmental authorities.
In terms of technology, depending on the purpose of a project, various energy
devices at different stages of development can be deployed at a site. Some sites
are dedicated to demonstration where new devices can be evaluated, whilst
at commercial sites, devices that have already been tested at prototype scales
(proven technologies) are deployed.
Project development is a team effort that requires effective and close
collaboration of technical, legal, financial, and business experts with authorities
and stakeholders (e.g. local communities, fishers).
If a project is well designed, it can potentially attract investors and financial
resources. As the levelized cost of energy for marine renewable energy projects
is still significantly higher than other conventional (e.g. thermal power stations)
and renewable (e.g. onshore wind) sources, policymakers create incentives to
encourage investments in this sector. This is a key issue in the success of marine
renewable energy projects.
Operation and maintenance of a project is the next step after construction of
a project. At this stage, monitoring of device performance and their impacts on
the environment can provide valuable data for other projects.

10.4 IMPACT OF TIDAL ENERGY EXTRACTION ON SEDIMENT
DYNAMICS
Previous studies into the environmental impacts of marine renewable energy ex-
traction have focussed on issues that do not directly influence the resource itself,
for example, collision risk of marine mammals and the effects of underwater
noise (e.g. [50]). However, there is one aspect of the environmental impacts
of marine renewable energy that can have a direct influence on the resource—
changes to sediment dynamics and associated morphodynamics [51]. These
issues are introduced briefly in this section, covering changes to offshore sand
banks (due to tidal stream energy conversion), and changes in sedimentation
as a result of tidal lagoon operation. We also discuss how tidal stream array
operation can alter sediment transport pathways for varying degrees of tidal
asymmetry. However, it is important to emphasize that at present, prior to
the existence of and long-term monitoring of lagoons or significant scale
tidal energy conversion, feedback between energy extraction and sediment
dynamics/morphodynamics remains a research question, and one that is yet to
be observed in situ. Although it is likely that large-scale wave energy arrays will
lead to changes in sediment dynamics, the change is likely to occur between the
array and the coastline, and is therefore not likely to influence the incident wave
climate (e.g. [44]).