Hypothesis: A passion for science runs in the family.

Exhibit A: Rachel Tamashiro, 15, a sophomore at St. Andrew’s Priory.

Tamashiro’s sister Sarah, who graduated from Priory last year, was a winner at the Hawai‘i State Science and Engineering Fair three years in a row.

This year, Rachel and junior Regina Huang, 16, will be entering with an innovative bladeless turbine designed to produce electricity from Hawaii’s offshore currents. And they’ve snapped on masks and snorkels to supervise their sea trials.

Their helical, elliptical design is similar to other "auger" turbines, but is vertical and has a feature to keep the turbine clear of seaweed and debris like nets and fishing lines. Sharp edges at the top and the bottom of the turbine will eventually trim off any snagged netting, fishing lines or seaweed, they say.

"By looking at previous water turbine designs we saw that there were a lot of — not really flaws, but just something that affected the movement, like fish," Rachel said in an interview at the school. "Fish would get caught or they would get harmed, they would be endangered. And if debris or vegetation ran into the turbine because it had blades, then that would get caught and it would affect the spin of the turbine."

The turbine is attached to a moored raft equipped with a generator that turns the kinetic energy into electricity.

In their first sea trial in Maunalua Bay, they generated less juice than what is in a AA battery. But they insist the project has untapped potential.

Their science fair adviser, chemistry teacher Michael Grech, agrees.

"I think it’s quite a unique design," he said. "I guess what impresses me the most is it does not have that much of an impact on animal life. It is something that is going to exist in the ocean and coexist with organisms in the ocean and not interfere with how they live."

Shown the design via email from the Star-Advertiser, Luis Vega of the Hawaii National Marine Renewable Energy Center said: "I’m always excited when young students come up with great ideas … We desperately need American students to work on technology. So many kids don’t want to go into science."

That won’t be evident when the fair opens Monday at the Hawai‘i Convention Center, with judging Tuesday and awards presented Wednesday. There are projects by nearly 600 students from dozens of public and private schools.

Carolyn Kaichi, program manager with the Hawai‘i Academy of Science, which sponsors the fair, said the number of display projects was limited to 18 this year, down from 93 last year. That allowed room for more research projects, she said.

"We filled that void out. We would really like to encourage more students to do research projects."