BEST Researchers Boost Wind Energy Efficiency

Oregon BEST Grant Leverages Major Research Funding to Improve Wind Energy

Wind Turbines, Columbia River

The problem with harnessing energy from the wind is obvious: sometimes the wind blows, and sometimes it doesn’t. So how do we store energy generated on windy days so we’ll have it on calm ones? And how do we integrate the variable nature of wind energy into the regional power grid in a smart way that keeps electricity levels steady. And how do you accurately forecast when the wind will be blowing, for how long, and at what speeds?

Complex questions. But as pressure for more reliance on renewable energy, power companies in search of answers to these questions are looking to the expertise and laboratory facilities of Oregon BEST researchers.

At Oregon State University, Oregon BEST researchers Alex Yokochi, Annette von Jouanne, Ted Brekken and others have used a $35,000 matching grant from Oregon BEST to leverage more than $725,000 in additional funding from the Bonneville Power Administration, Central Lincoln People’s Utility District, and other entities—funding that’s helping explore a range of ways to make wind energy more effective.

The research team has created a one-of-a-kind, lab-scale power grid that is being used to test storage devices and to determine how best to integrate wind power into the existing grid alongside energy from other sources.

“This is the only university-based experimental lab grid in the U.S. for testing energy storage solutions for renewables integration into the grid at this power level,” Yokochi says. “There’s a lot of dry work and lab models, but nobody’s actually built one like this and verified that the assumptions made can be implemented in practice.”

OSU's Alex Yokochi in WESRF LabThe lab grid is located in OSU’s Wallace Energy Systems & Renewables Facility (WESRF, shown left), where von Jouanne, Brekken, and other colleagues are leading the nation in development of renewable energy technologies, including wave energy. Results from the project will also be applicable to other forms of renewable energy such as solar and wave energy.

The lab-based grid can simulate power generated from different sources (wind, hydro, wave, etc.) at fluctuating levels, as well as a load that represents power consumption by users. The grid enables researchers to determine how best to integrate power from different sources to keep the power supply stable and reliable.

This is important, because when the wind blows hard, integrating that energy into the grid requires reducing the power input from other sources, such as hydroelectric dams and fossil sources. Then, when the wind decreases, utility operators make up that difference with other energy sources. “You can’t ramp up a coal plant very quickly,” Yokochi says. “Small natural gas turbines work well, but we’d like to minimize the use of that.”

Hydroelectric power is much easier to regulate, which helps integrate wind power. “We’re fortunate here in the Pacific Northwest because we have so much hydro power,” he says.

Still, using these sources on short notice to smooth the variability of wind power can threaten grid stability, increase maintenance costs and increase the cost of large-scale wind power integration.

The lab grid is a powerful research tool that’s allowing the research team to try an infinite range of options and to test energy storage methods.

OSU's Alex Yokochi with model“Things that look great on paper don’t always work the way you want in practice,” says Yokochi.

The researchers say more accurate wind forecasting would also help integration of wind energy, giving power engineers more time to plan and regulate the flow of electricity from other sources.

Another big help would be dependable storage capability, so wind energy could be stored, then meted out as needed. Wind farms currently have no storage devices, which is why the Oregon BEST researchers are looking to see if large batteries, flywheels, and other technologies are viable ways to store wind power.

They are analyzing a range of battery types to determine if a massive 20 to 40 megawatt battery (think the size of a large barn) might do the trick. But the challenge is developing a battery with a long life-cycle capability, one that can be charged and discharged many times.

“We really need a technology that’s going to give us at least 10,000 deep discharge cycles, which is a lot more than any technologies that have been proven so far,” says Yokochi. “Zinc bromide and sodium sulfur batteries look promising at this point, and we’re also looking at other energy storage technologies, including the use of flywheels.”

Thanks to the lab grid, the researchers can attach and test any type of storage device. And industry partners can potentially test products in the lab grid, as well.

Td Brekken & Annette von Jouanne, OSU professorsThe team is also researching how a battery-to-grid interface will function when tapping the stored wind energy and adding it to the grid.

A general belief is that grids can handle about 15 percent wind power, Yokochi says. The balancing authority area under BPA jurisdiction passed the 15 percent threshold in 2008, is expected to pass 25 percent this year, and might reach the unprecedented level of almost 40 percent in 2010 in light of the Large Generation Interconnect Agreements that have been requested for the near future. This is a technical challenge, and thus energy storage must be explored, since “business as usual” will not be able to handle that increased level of wind integration.

So the work of von Jouanne, Brekken, and Yokochi is more critical than ever. The team is using a new $40,000 matching grant from Oregon BEST to leverage an additional $460,000 from funding sources, including the BPA, and they have applied for an additional $1.6 million in funding from the National Science Foundation.