Offshore Renewable Energy refers to the generation of electricity from
ocean-based resources. These include wind turbines located offshore in the oceans and
Great Lakes and marine based energy sources including waves, tides, and salinity and
thermal properties. Marine based projects are considered “offshore” if they
employ ocean resources. For instance, a tidal generator located at a river’s mouth
is considered offshore since it uses the flow of the ocean tides.
The NOEP offshore renewable energy database has been completely updated with projects in
the U.S. and Europe. The search facility for the new database ill be made available in September 2017.
Until then, the map below can be used to browse the updated data.
Map: Offshore Renewable Energy Projects
Over 80% of the United States population lives in coastal states, which comprise 80% of the
national electricity demand (U.S. Department of Energy). The coastal states are
the most densely populated areas with the highest average property values. In 2013, coastal
counties in the U.S. had a housing and population density of over double that of
the U.S. as a whole (see our
Population and Housing section). 2015 data collected by Trulia reveals that the
average price of real estate in coastal states is over $90,000 more than that of inland
states. In light of the highly competitive nature of coastal land resources among other
factors, many, especially the energy sector, are now looking toward the sea for industrial
development. (McCauly et al. 2015).
Offshore renewable energy has been proposed as an important addition to the U.S.’s energy
portfolio in order to increase energy security, and reduce carbon emissions. However, offshore
renewable energy is in its infancy, and still faces many challenges such as lack of competitive
costs, a developing supply chain, and unknown impacts and repercussions for the
surrounding marine ecosystems (International Energy Agency 2013; TETHYS).
Conditions for Feasibility of Each Energy Type
||Grounded: 0-80 meters
Floating: 0-? meters
|| 7 meter/sec wind speed at 90 meters above sea level ||
- Northern California
- Southern Oregon
- Northeast (NY-ME)
||30° - 60°
||Off west coast of continents
||> 1,000 meters
||0° - 35°
- Surface water: > 25° C
20° difference in temperature surface water and extracted water
||Shallow water (0 — 30 meters)
||Fast current speeds ||Located at place of high marine flow* ||
(Gulf Stream current)
|Tidal Range ||
- Located at ocean inlet
- Tidal height range at inlet > 7 meters
- Washington state
||1.5 — 2 meter/sec water speed
||Located at place of high marine flow*
*Places of high marine current flow tend to be: narrow straits, between islands, around headlands, or entrances to lochs, bays, and harbors
**Table information sourced from IRENA, NREL, and Ocean Energy Council
Each offshore renewable energy source has varied availability and potential
capacity for development in the U.S., based on where the ideal conditions align.
The mapping of these conditions are critical in
determining where the U.S. employs these renewable energies. For example,
ocean thermal, though it can generate a large amount of power, is only feasible
in places that hold the warm, tropical surface water that thermal conversion
requires (International Renewable Energy Agency). In contrast,
wave energy is best farther away from the equator where waves
are the fastest, largest, and most consistent. If wave energy develops in
the U.S., it would likely occur in the Pacific Northwest or Alaska
(IRENA). The Northeast region holds most promise for offshore
wind—this is where water depth is both shallow (i.e. turbine
installment and maintenance is cheaper) and wind speeds are large
(National Resources Defense Council).
Currently, there are few commercial offshore renewable energy operations
in the U.S.. However, a number of developing technologies in marine hydrokinetic
and offshore wind powers have drawn increasing interest. Because of
this and the importance of new energy sources, NOEP
has compiled a database of available infomation related to offshore renewable energy projects
in the U.S.. Currently, the database contains all known offshore
projects and any data regarding their locations, project types, stage of development,
projected capacities, installation costs, expected employment, and more.
Eventually, NOEP will also include international project data to track the more advanced progress of these emerging industries abroad.