WATER POWER TECHNOLOGIES OFFICE
Harnessing Marine Energy Resources for Clean, Reliable Power

Marine energy technologies transform the incredible amount of power in waves, tides, and ocean and river currents into clean electricity. In fact, the total available marine energy resource in the United States is equivalent to approximately 57% of all U.S. power generation. Even if only a small portion of this technical resource potential is captured, marine energy technologies would make significant contributions to U.S. energy needs.

In the short term, marine energy could serve U.S. coastal communities and provide local, affordable, and clean power to rural and remote island communities, which often rely on expensive shipments of fossil fuels. Marine energy technologies could also power offshore work such as ocean observing equipment or aquaculture farms, increasing energy reliability for ocean industries that typically work far from traditional power sources. In the longer term, marine energy could play a role in decarbonizing the country's power grid, especially since waves tend to be strongest when the sun does not shine and tidal energy is predictable for years in advance. 

Through its Marine Energy Program, the U.S. Department of Energy's (DOE's) Water Power Technologies Office (WPTO) supports projects focused on research, development, demonstration, and commercial activities that advance the development of reliable, cost-competitive marine energy technologies and reduce barriers to deployment.

Explore a selection of these projects featured in WPTO's 2022-2023 Accomplishments Report.

Advancing Research to Drive Cost Reductions and Improve Device Performance

WPTO supports research to improve marine energy device performance, reduce costs of existing designs, and develop new capabilities that can allow for entirely new designs and approaches to harnessing marine energy. In 2022 and 2023, researchers working on WPTO-supported projects:

• Deployed a first-of-its-kind electrochemical marine carbon dioxide removal device, which is designed to sequester 100 tons of carbon dioxide annually or about as much as 50 cars emit in a year. The team is also using simulated marine energy data to understand the potential to power mCDR systems with marine energy. 
   
• Designed a new, potentially more comprehensive and accurate way to measure wave energy. With more accurate, consistent data, technology developers can more easily compare their design to others and glean how much energy their device might produce in real ocean waves.
   
• Developed an autonomous device that can monitor environmental conditions surrounding potential wave energy deployment sites, help determine optimal placement of devices, and observe potential environmental effects from deployed wave energy converters (WECs). 
   
• Proved that taking a co-design approach to building a WEC or designing the body and control system of the device at the same time results in a better-performing device. The team also found that combining a magnetic spring, a mechanism that powers WECs, with the co-design approach resulted in a more durable device. 
   
• Investigated using a laser to modify the surface of marine energy devices to reduce corrosion and biofouling (the accumulation of plants, algae, and other microorganisms on device surfaces). Corrosion and biofouling can disrupt marine energy devices by increasing the amount of maintenance needed, impacting the level of performance and potentially reducing equipment life spans.

Supporting the Design and Validation of Marine Energy Devices

It is a challenge to install, operate, and maintain marine energy devices in a cost-effective and reliable manner in harsh marine environments. To help overcome these challenges, WPTO supported projects through which researchers:

• Tested a WEC in hurricane-level waves, proving the durability of the prototype and demonstrating that marine energy can reliably power data collection and ocean exploration activities. This device is specifically designed to provide power to oceanographic and meteorological buoys.
   
• Tested devices designed to capture energy from river and tidal currents. The deployments of two devices, which took place in Millinocket Stream in Maine, provided insights into operations and power performance (or how well the devices capture power from the stream) and for further refining the design.
   
• Designed several innovative WEC concepts that could power sensors on an ocean observing buoy. The WEC could potentially alleviate "brownouts" that occur when other power sources cannot produce the total amount of energy required for the sensors to operate. 
   
• Added new features to an open-source modeling tool to enable marine energy turbine developers to simulate how much energy different versions of their designs might generate. Several developers already used the tool to predict loads on rotors (the rotating assembly on a turbine), check results they generated from commercial modeling tools, and better understand floating platform motions.
   
• Investigated a new concept for harnessing energy from ocean thermal gradients, the differences in temperature between the ocean's cold, deep water and warmer surface water. Ocean thermal gradients have great potential to power uncrewed underwater vehicles in deep-water research, investigation, and exploration.
   
• Completed the first step in developing a framework to support remote, coastal, and island community-driven energy transitions. Researchers, technical assistance experts, and DOE program officers could use this framework to better understand the readiness of communities for marine energy technology demonstration projects and their operation.

Enabling Testing and Information Sharing

Testing marine energy technologies is inherently more complex and time consuming than it is for land-based energy generation technologies. With that in mind, WPTO works to make it faster, easier, and more cost effective for companies to take steps toward deploying their devices while abiding by marine regulatory protections and standards. In 2022 and 2023, WPTO-funded projects: 

• Supported the installation or continued construction of critical testing infrastructure that will help advance the development of marine energy technologies. This included a system that can emulate ocean waves at the National Renewable Energy Laboratory and a hybrid research vessel at Pacific Northwest National Laboratory, among others. 
   
• Surpassed $10 million of technical support across more than 100 marine energy projects through the Testing Expertise and Access for Marine Energy Research (TEAMER) program