Spring 2014


Can Humboldt Bay Give Us ‘Blue Energy’?

Professor and Students Investigate Renewable Energy With Massive Potential

Blue energy—for the unfamiliar—is a promising form of renewable energy that’s free of emissions and doesn’t depend on favorable weather conditions. And harnassing it is the goal of HSU engineering students as they develop a power plant in Humboldt Bay.

Design of a blue energy generation facility for the Humboldt Bay Municipal Water District is a continuing project undertaken by students in Professor Andrea Achilli’s Environmental Resources Engineering capstone design class.

professor in lab

Professor Andrea Achilli, left, works with graduate student Matthew Jackson.

Blue energy, Achilli says, is naturally released during osmosis, such as when a river flows into the ocean. Freshwater is drawn to the saltwater, creating a buildup of pressure.
Recovering that energy is achieved through a process called pressure-retarded osmosis (PRO). During PRO, freshwater is drawn through a semi-permeable membrane into a saltwater solution. Releasing the pressure through a turbine generates power.

The innovation has gained traction in recent years. In 2009, Norwegian company Statkraft completed the world’s first osmotic power plant and in 2011, researchers at Stanford University estimated that osmotic power had the potential to meet 13 percent of the world’s energy needs.

Achilli and his students are assessing the technical and economic feasibility of constructing a PRO facility at the site of the old Samoa Pump Mill west of Eureka. The plant would draw water from Humboldt Bay into the Pacific Ocean, generating large amounts of renewable energy. Students are heavily involved in all aspects, gaining hands-on experience collaborating with a client and managing a project from inception to completion.

“We’ve pretty much been working from the ground up,” says Chuck Swanson (’13, Environmental Resources Engineering). “Our involvement has been everything from trying to assess the site’s infrastructure to testing a new technology.”

Humboldt bay

“It’s pretty exciting to be a part of such novel and promising research,” says Meghan Heintz (’13, Environmental Resources Engineering), a student in Achilli’s class. “It’s also exciting because Professor Achilli is a leading expert in the field.”

Before joining HSU, Achilli studied membrane-based energy systems as both a graduate student and post-doctoral research associate at the University of Nevada, Reno. His current research focuses on membrane contactor processes and hybrid systems, renewable and sustainable energy systems and biological processes for water and wastewater treatment.

Results from the course will determine whether it will be possible to house the first river-to-sea PRO facility in the United States at Humboldt Bay.