This intern summarized their work over the summer supporting the Tethys database, which collects documents on environmental effects of renewable energy from the sea. The intern wrote descriptions of interactions between stressors from energy devices and receptors in the environment. They also added new documents to Tethys and retagged older documents to improve accessibility. This work will help various groups understand environmental risks and make more informed decisions, while advancing offshore renewable energy.

1. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce
Development for Teachers and Scientists (WDTS) under the Community College Internships Program (CCI).
Kellie O’Connor Tethys: Environmental Effects of
Renewable Energy from the Sea
Abstract
Increased development of offshore renewable energy (such as tidal, wave, and offshore
wind) has led to more interest in how these devices affect the environment. Tethys
(http://tethys.pnnl.gov) is an online database that collects documents related to potential
environmental issues caused by in-stream riverine, ocean currents, ocean thermal energy
conversion, tides, waves, and offshore wind devices. Tethys organizes documents by stressors,
which are characteristics/side effects from devices that impact the environment, for example
noise or chemicals, which can positively or negatively affect receptors, which includes
organisms, such as birds, fish, and marine mammals, and also parts of the environment such as
nearfield habitat and the far field environment. I helped the Tethys project by defining how
receptors would react to a stressor in a new organization category of Tethys called interactions.
Documents will be easier to access by defining what happens between stressors and receptors. I
also worked on retagging documents to make them easier to find, and I processed and added new
documents to Tethys. This work will allow project developers to find documents related to
minimizing risks to the environment from projects, will help regulators to make decisions
regarding the environment, will help stakeholders find possible environmental problems from
projects, and will help researchers find research to identify research gaps and carry out important
research.

2. 1
This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce
Development for Teachers and Scientists (WDTS) under the Community College Internships Program (CCI).
Introduction
The many offshore renewable energy devices used in today's industry produce energy
from differing sources, such as tides, waves, and offshore wind.
Tidal devices include tidal turbines, which are generally placed near the bottom of the
water column. The most common environmental effects that can arise from these devices are
collision with turbine blades, and impingement as high velocity water pushes organisms near the
turbine[1]. Another tidal device is a tidal barrage, which consists of dams built across the
opening of a bay or estuary, and which collect potential tidal energy with turbines as the water
level rises and falls. The last type of tidal device is a tidal lagoon, which uses circular retaining
walls implanted with turbines to collect potential tidal energy.
Another source of offshore renewable energy collects power from waves with a wide
variety of device designs. Some wave energy devices include point absorber buoys, which use
the rise and fall of wave swells to drive pumps and produce energy, other devices include
oscillating wave surge converters, which usually have one end secured to a structure/seabed,
with the other end floats, using the motion of the free end to create energy. Examples of ocean
energy devices include turbines that collect energy from ocean currents, such as the Gulf Stream.
Another example would be OTEC (Ocean Thermal Energy Conversion) devices, which
use the temperature difference between the sun-warmed surface of the ocean and the cooler
deeper layers of the water to produce energy. OTEC devices include: closed-cycle devices, open-
cycle devices, and hybrid devices. Closed-cycle OTEC devices pump warmer surface seawater
through a heat exchanger where a liquid with a low-boiling point is vaporized and used to turn a
turbine as the vapor expands. Cooler seawater from deeper layers is then pumped through a
second heat exchanger in which the vapor is then condensed back to a liquid to be reused. For
open-cycle OTEC devices, sun-warmed surface seawater is put into a low-pressure container that
causes the water to boil, and which then turns the turbine as the steam expands. When exposed to
the cooler deep layers of seawater, it condenses back into water, with most of the salt from the
seawater left in the container. The last type of OTEC energy devices are hybrid devices where
the sun-warmed water enters a vacuum chamber, where it is evaporated into steam, which is then
used to vaporize a low-boiling point liquid, which then turns a turbine to produce energy, with
fresh water being created during the earlier stage.
Offshore wind has many different types of foundations, usually found in fresh or
saltwater environments. The offshore wind turbines are almost all three bladed upwind design.
Offshore wind turbines can be found on monopile foundations which are steel piles driven into
the seabed, tripod fixed bottom foundations which are three connected piles driven into the
seabed, gravity foundations which have a heavy concrete or steel base set on the seabed, gravity
tripod foundations which are two heavy structures connected by three legs, and lastly floating
structure foundations where the turbines are moored to the seabed and stabilized with ballast.

3. 2
This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce
Development for Teachers and Scientists (WDTS) under the Community College Internships Program (CCI).
Different Offshore Renewable Energy Devices: The first is a SeaGen Tidal Turbine, the second is an Ocean
Energy Wave Buoy, and the last is a Principle Power Offshore Wind Turbine
Tethys
Tethys (http://tethys.pnnl.gov) is an online database that collects documents related to
environmental issues caused by offshore renewable devices. Tethys was designed and built by
Pacific Northwest National Laboratory (PNNL) in 2009 and it is funded by the U.S. Department
of Energy; PNNL continues to operate and improve Tethys. The database currently has
approximately 2500 documents. The two main functions of Tethys are to assist in increasing the
exchange of knowledge about the environmental effects of offshore renewable energy, and also
to function as a community for offshore renewable energy practitioners. Work is constantly
being done on the database to make it more accessible, especially since it is a well renowned
source for research internationally.
The organization of the Tethys database is unique. Documents are organized in the
Tethys Knowledge Base by title, author(s), publication date, technology type (i.e. tidal or wave
device), type of content the document (i.e. journal article or presentation), and finally by
stressors and receptors. Stressors are certain aspects or side effects of the device that can affect
the environment. Some stressors of the device may include: noise, electromagnetic fields,
chemicals, light, energy removal, dynamic (moving) parts of the device, and static (stationary)
parts of the device. These aspects can affect receptors, which are the parts of the environment
being affected by the device[2]. These can include organisms such as: birds, bats, marine
mammals, and sea turtles; stressors can also affect the physical environment such as far field
habitat and near field environment, and can lastly also affect socio-economics such as tourism
and fishing. The majority of what I worked on this summer was how receptors interact with
stressors. For example, if a fish approaches a tidal turbine located several meters below the
surface of the water, would the fish collide or evade the turbine? These interactions included
collision/evasion of devices, attraction (aggregation) of organisms around the device, avoidance
of the device and potential loss of habitat for organisms, change in sediment transport or water
quality due to energy removal, and lastly entrapment of large organisms like whales by
components such as mooring lines[3].

4. 3
This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce
Development for Teachers and Scientists (WDTS) under the Community College Internships Program (CCI).
Marine mammals such as this orca are at risk for collision with tidal turbines and must be protected
My Work This Summer
This summer my main task was to write descriptions about the interactions. Besides
interactions, I also worked on two different parts of Tethys. One of these parts was adding new
documents to Tethys. This involves reading documents to see if they are relevant to Tethys, and
adding them if relevant. The second part involves retagging older documents on Tethys. This is
important to the Tethys mission, since the database contains documents from prior to 1999, as
well as because of changes to Tethys since its beginning in 2009. Retagging is necessary
because while documents have been added since the start of Tethys in 2009, they have never
been reviewed on a large scale like the retagging effort.
Tethys Knowledge Base and Map Viewer: These images show how Tethys is organized. The first shows how
the documents are deconstructed into parts: author(s), dates, technology types, and stressors/receptors. The
second shows from what countries the documents come from

5. 4
This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce
Development for Teachers and Scientists (WDTS) under the Community College Internships Program (CCI).
Progress
I made varying levels of progress among the three different Tethys tasks on Tethys I
worked on this summer. The first section, Interactions, made up the core of my project and was
probably the most complete aspect among the three tasks. For Interactions, I wrote descriptions
for each of the different types of Interactions between stressors and receptors, such as
Collision/Evasion or Attraction/Avoidance. To prepare for writing these descriptions, I
researched documents on Tethys and Google Scholar that described interactions between the
environment and offshore renewable energy devices. I completed the descriptions and they are
live on Tethys.
The second task that I worked on was adding documents to Tethys. This involved first
reading the document to see if it is relevant to the standards on Tethys, such as checking to see if
it is related to offshore or land based (wind turbines) renewable energy devices. Then I would
process the document to provide the necessary format for Tethys, add the document, and add
relevant tags. The processing task was done through a webform on Tethys that involves adding
abstract, title, and authors to the document and then filling relevant checkboxes that indicate
device type, stressors and receptors, and type of content. This work this well, although I found
many duplicate documents already available on Tethys; from these I learned more about the
topics.
The last task I worked on was retagging documents that had previously been added to
Tethys. It was discovered that a number of documents added to Tethys might need further
tagging and tag correction; I was part of a team that worked on this quality assurance task this
summer. For this task, different years were divided among the team. This task had become
necessary due to the growing amount of documents found in the database. Retagging involved
rereading documents that had been added to Tethys, to see if they had been properly tagged
when they were first added to Tethys, and noting patterns or sources of documents that might
lead to miss-tagging. This task was needed to ensure the accuracy of Tethys.
Although I succeeded in each of the tasks I undertook, the short amount of time I was at
PNNL (10 weeks) was not enough to finish all the work I would like to have completed,
particularly as I needed to develop my understanding of the topic of offshore renewable energy
to ensure my work was accurate.
Future Work
In the future, the tasks I have worked on will have a lot of impact on Tethys. The first
task, Interactions, is most likely the most significant because of how it has already been
implemented on Tethys and will be added to in the future. Like the other filters used to organize
documents in the Tethys Knowledge Base, such as type of content or technology type,

6. 5
This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce
Development for Teachers and Scientists (WDTS) under the Community College Internships Program (CCI).
Interactions will become a new filter on the Knowledge Base. This will allow the documents
already on Tethys to be better organized and more accessible.
The second task, adding documents, will also have an impact. Adding new documents to
Tethys is key to ensuring relevancy. This is important because Tethys currently has the most
pertinent documents from the last 20 years of research, making it a well-recognized and
renowned resource internationally.
The last task, retagging documents, also has an impact much like the impact of adding
new documents to Tethys. By removing incorrect tags and adding correct ones, researchers can
be reassured that the documents that they are searching for on Tethys are applicable to their
research, which is especially important for countries outside of the United States that are
currently working on offshore renewable energy. This task is currently about half finished by the
group, and will continue to be worked on in the near future.
Impact
Because Tethys is a well renowned database worldwide, the work done on Tethys will
have much impact on varying interest groups. For marine energy technology and project
developers, the work done on Tethys will help them to find documents showing how to minimize
environmental effects from devices and projects. For regulators, it will help them to become
more informed and able to assist in making decisions for permitting marine energy devices while
still protecting the marine environment. In the case of stakeholders, it will help them to
understand real world risks from ocean energy devices, as well as helping them to reduce
concerns for low risk interactions. Lastly, it will help researchers find supporting research for
work, identify research gaps, and help them to make new collaborative contacts with other
researchers worldwide.
The task I worked on the most, Interactions, will have a major impact on the varying
interest groups. By categorizing documents based on this new terminology, , Tethys is able to
allow researchers from different countries to better communicate with established terms for these
Interactions. This will in turn help to fuel sharing of concepts and ideas across the globe.
The work in general that I did this summer will have a crucial impact in moving forward
offshore renewable energy. By making Tethys more accessible, more researchers and other
interest groups will use Tethys. This will then lead to an influx of interest in how marine energy
devices affect the environment, which will in turn lead to more informed decisions and
additional research on how these devices may affect the environment.
Conclusion
In conclusion, I would say that the tasks I worked on this summer have been successful,
and will likely have a good effect for the future of Tethys, while also helping me to become more

7. 6
This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce
Development for Teachers and Scientists (WDTS) under the Community College Internships Program (CCI).
informed about offshore renewable energy and its effects on the environment. By learning about
the effects of offshore renewable energy to complete my tasks, I was able to better do my tasks.
While each task I took on was not completed during my time at PNNL, the tasks will be useful
for Tethys in the future. The tasks I worked on will continue to be implemented on Tethys.
Lastly, these tasks will have a major impact for varying interest groups by making Tethys more
accessible, which will increase interest in the environmental effects from offshore renewable
energy. I would say that this internship was very helpful in supporting my decision to major in
Biological Oceanography, while also allowing me to learn more about the Department of
Energy, and the type of work that the Department does. I also think that this internship will help
me in the future by giving me work experience this summer, and also helped me become more
prepared for when I transfer to a four-year college by giving me more insight into the
Department of Energy’s work on offshore renewable energy devices.
References
1. Polagye, B.; Copping, A.; Kirkendall, K.; Boehlert, G.; Walker, S.; Wainstein, M.; Van
Cleve, B. (2010). Environmental Effects of Tidal Energy Development: Proceedings of a
Scientific Workshop. Tidal Energy Workshop, Seattle, Washington.
2. Copping, A.; Hanna, L.; Van Cleve, B.; Blake, K.; Anderson, R. (2014). Environmental Risk
Evaluation System - An Approach to Ranking Risk of Ocean Energy Development on
Coastal and Estuarine Environments. Estuaries and Coasts,, 1-16.
3. Copping A, L Hanna, J Whiting, S Geerlofs, M Grear, K Blake, A Coffey, M Massaua, J
Brown-Saracino, and H Battey. 2013. Environmental Effects of Marine Energy Development
around the World for the OES Annex IV, [Online], Available: www.ocean-energy-
systems.org.

8. 7
This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce
Development for Teachers and Scientists (WDTS) under the Community College Internships Program (CCI).
Appendix A
Participants
● Kellie O’Connor: CCI Student
● Dr. Andrea Copping (PNNL): Mentor/Tethys Manager
● Jonathan Whiting (PNNL): Scientist/Tethys Manager
● Luke Hanna (PNNL): Scientist/Tethys Manager
● Molly Grear (PNNL): Retagging Team
● Allison Cutting (PNNL): Retagging Team
Scientific Facilities
Pacific Northwest National Laboratory’s Seattle Research Center
Notable Outcomes
- CCI Poster: Tethys: Environmental Effects of Renewable Energy by Kellie O’Connor
- Contributions to http://tethys.pnnl.gov