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Marine Sciences Division

Renewable Energy

Algal Biofuels

Algal Biofuels

Algae are a promising source of renewable energy, and algae-to-biofuel conversion has been successfully demonstrated at laboratory scale. However, existing algae cultivation methods are inefficient for supporting the needs of commercial-scale biomass production. Improving the economics of microalgal biofuels production requires identifying novel microalgae strains with superior biomass and lipid productivities. It also requires selecting the best strains for outdoor cultivation and subsequent commercialization, which means determining how strains perform in outdoor ponds at different geographic locations and in different seasons, and how raceway ponds should be operated to achieve optimum biomass productivities.

Researchers at MSL have developed an integrated strategy for efficiently and cost-effectively screening strains for their potential to exhibit high biomass productivities in outdoor ponds. This strategy consists of the following four steps:

  • Experimentally characterize microalgae strains in terms of their growth rate response to light and temperature, including biomass losses overnight.
  • Predict biomass productivities at any hypothetical outdoor pond location in the United States with a biomass growth model using the experimentally determined species-specific input parameters in conjunction with historical sunlight intensity and temperature data.
  • Validate the model's performance via climate-simulated culturing in PNNL's state-of-the-art LED-lighted and temperature-controlled indoor raceway ponds.
  • Test strains in PNNL's raceway ponds in Arizona.

This strategy is currently being applied in a recently awarded project titled "Algae Development of Integrated Screening, Cultivar Optimization and Validation Research (DISCOVR)." The aim of the project is to reduce the cost and time needed to move promising algal strains from the laboratory into production. The project's early work relies on PNNL's Laboratory Environmental Algae Pond Simulator mini-photobioreactors (LEAPS). The system mimics the frequently shifting water temperatures and lighting conditions that may occur in outdoor ponds throughout the world. Researchers are evaluating approximately 30 algal strains for growth, and further studying a subset to measure oil, protein, and carbohydrate content, all of which can be used in biofuel production. The next phase of the project will test promising strains in large outdoor ponds in Arizona to evaluate the performance and accuracy of the lab-based screening process. The final phase will continue outdoor testing to assess growth under different natural lighting and temperature conditions. These results will be entered into PNNL's Biomass Assessment Tool, which identifies the best geographic locations for algae biofuel production.

"Local Lab fosters big biofuel potential." Sequim Gazette, March 24, 2015.

Environmental Technologies Development and Testing

Environmental Technologies Development and Testing

Ocean renewable energy technology will grow and mature into a sizable industry in the next 10-15 years. Realizing the significant benefits of ocean energy requires investigating the potential environmental effects of energy generating devices as well as their long-term durability, efficiency, and operating costs. This means testing in marine waters under known conditions, in an environment similar to where devices will be deployed commercially. Testing at intermediate stages of device development allows for ease of deployment, maintenance, and retrieval, with few constraints on the deployment window to keep pace with the speed of technology development and contain costs.

To meet the need for intermediate-scale testing, MSL hosts the Triton Initiative (formerly known as the Marine Energy Environmental Technologies Initiative). The Triton Initiative advances development and integration of environmental technologies, instruments, platforms, and data analysis capabilities for investigations around wave, tidal, and offshore wind energy converters. MSL's location at Sequim Bay is ideal; the site is well characterized, and renewable energy R&D has been established as a compatible marine use for the area.

International Ocean Renewables Information System

International Ocean Renewables Information System

Advancing the developing international marine renewable energy industry requires sharing information and identifying data gaps that need to be addressed. One of the largest areas of uncertainty is the siting and environmental permitting processes required to deploy marine renewable energy technologies.

To address this uncertainty, PNNL is working with the U.S. Department of Energy to lead the Annex IV project. Under the Ocean Energy System (OES) initiative, Annex IV is an international project that collects and makes accessible information and metadata on marine renewable energy projects and research studies through the Tethys database. Annex IV also strives to facilitate communication and collaboration among an international community of marine renewable energy practitioners by building a commons around the Tethys database and the various Annex IV webinars, workshops, expert forums, and other activities that are held on a routine basis. Tethys is also used as a platform for supporting outreach and as a list serve (Tethys Blast) that alerts researchers and stakeholders to new documents as well as current events. Tethys also provides basic regulatory information and contacts for experts and organizations engaged in marine energy studies.

Offshore Wind

Offshore Wind

As the United States pushes for a more diverse and clean energy portfolio, offshore wind energy has the potential to supply over 4,000 GW of capacity domestically. However, two of the greatest immediate challenges to developing a domestic offshore wind industry are uncertainty about the potential environmental effects of offshore wind farms and the difficulty of navigating siting and permitting processes.

Scientists at MSL are focusing on ways to address some of these environmental uncertainties and concerns. We are developing software tools and related solutions to improve bird and bat recognition around wind turbines using infrared video. The goal of these studies is to enhance the overall understanding of how birds and bats behave around and interact with wind turbines. MSL has also developed the Tethys knowledge base to house, organize, and make widely accessible information and literature dealing with the environmental effects of offshore renewable energy. PNNL-MSL also participates in Task 34 or WREN, an international collaborative project under IEA Wind to address environmental issues associated with commercial development of land-based and offshore wind projects. MSL also works to provide tools to share information and data in order to facilitate more communication and collaboration between researchers, regulators, and developers to assist the sting and environmental permitting processes.

Conventional Hydropower

Conventional Hydropower

Hydropower is a unique component of the national long-term energy strategy: 52% of hydropower generation is owned and operated by the Federal government, and the remaining 48% is closely tied to the public sector through strong environmental and public interest regulation. The public nature of hydropower ensures that key challenges in environmental concerns and sustainability have to be addressed, both for growth of new hydropower as well as continued operation and regulatory compliance of the existing fleet.

MSL scientists collaborate with others across the Pacific Northwest to develop the scientific basis for modeling ecohydrological relationships in river-floodplain wetlands and adjacent terrestrial and aquatic habitats, including fish communities, plant communities, and the physical environment. The objective of floodplain- and basin-scale research is to mitigate environmental impacts and improve the effectiveness of hydropower operations and ecosystem restoration actions by understanding effects of altered system-wide environmental flows on plant communities and habitat functions.

Scientists at MSL work to mitigate the impacts of the Federal Columbia River Power System (FCRPS). Washington State is the nation's leading producer of hydroelectric power; the FCRPS produces approximately 40% of the national total. The National Marine Fisheries Service biological opinion on the impacts of the FCRPS on threatened and endangered salmon stocks has galvanized a large-scale ecosystem restoration program below the lowest major dam on the Columbia River, Bonneville Lock and Dam. The purpose is to increase the availability of tidal freshwater and estuarine wetland habitat for juvenile salmon during out-migration to the Pacific Ocean, along 234 river kilometers where tidal-fluvial hydrologic processes are affected by FCRPS operations, channelization by diking for agriculture, and water withdrawals for other societal uses.

Columbia River Estuary Workshop Presentations 2014

Columbia River Reference Sites Study

Columbia River Estuary Conceptual Model Project

Letting the water flow allows the salmon chums to grow The Daily Astorian, April 20, 2009

Wave and Tidal Power

Wave and Tidal Power

Energy generated from the movement of waves and tides ("marine energy") has the potential to contribute to the US low carbon "all of the above" portfolio of energy sources. However, stakeholders and regulators have concerns that the extraction of renewable ocean energy may pose risks to marine animals and birds, many of which are endangered or otherwise protected. Marine animals rely on underwater sound to communicate, navigation, and avoid predators. The addition of unnatural sound in the ocean can mask natural sound and interfere with animals' senses. Lack of research on potential risks and the high degree of uncertainty associated with the effects of underwater sound are two of the most significant concerns slowing the development of these fledgling industries in the United States.

Scientists at MSL are working to develop mathematical models of underwater acoustics and ocean hydrodynamics to use as predictive tools to help manage unnatural sound that is produced by marine hydrokinetic (MHK) devices. These models can simulate underwater sound propagation and help guide the siting and permitting of MHK devices while minimizing the cost and burden currently placed on financial backers and project developers interested in siting projects in the United States, using US-made equipment.

An ongoing project that is studying underwater sound propagation in energy-rich areas of the ocean is coupling a three dimensional ocean hydrodynamic circulation model (FVCOM), which resolves sea water density variations and surface elevation variations, with an acoustic model that solves underwater sound transmission loss, reflection from lateral, bottom, and surface boundaries, as well as refraction due to variable density field. The FVCOM hydrodynamics model simulates surface elevation, 3D currents, temperature, salinity, and density fields in the domain. The density field is used with the acoustic model for simulating sound wave propagation with refraction resolved. The change of surface elevation and moving of shoreline due to tides and storm surges are also accounted for in the acoustic model. The advantage of this approach is it permits formulation of the acoustics problem mathematically for meeting the challenges of coupling time domain hydrodynamic model with frequency domain acoustic model.

Marine Sciences Meets Renewable Energy PNNL, April 2015

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