Saturday | November 18, 2017
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Off the Grid

Several North Kohala farmers are benefiting from an innovative off-grid water pumping system powered by wind and solar.

Known as the Power Cube project, this $1.72 million demonstration system became fully operational this month and is capable of pumping more than 33 million gallons of water annually. That water is being used to irrigate land in Hawi and support the 14 participating farmers’ agricultural operations, said Fred Brown, Gen-X Energy Development LLC co-founder.

Power Cube is a Hawaii limited liability company with two members — Gen-X and Kohala Makani Wai LLC. Founded in 2009, Gen-X is a privately-owned Maui-based renewable technology firm that was responsible for the project and its construction management. Kohala Makani Wai is the land owner. The system was funded by these members, as well as through a grant from the U.S. Department of Energy, which paid for half of the cost, Brown said.

It was one of 40 renewable energy projects selected to show how unique commercial enterprises have the potential in assisting the state in achieve its collective goals under the Hawaii Clean Energy Initiative, an effort to achieve 70 percent clean energy by 2030, with 30 percent from efficiency measures and 40 percent coming from locally generated renewable sources. Besides “providing innovation for a better world and helping increase our independence from fossil fuels,” the new microgrid is also helping provide a reliable and cost-effective solution for Hawaii’s agriculture industry, Brown said.

Typically, agricultural operations in Hawaii require a complex series of irrigation systems, as well as pumps that consume lots of fossil fuel-based electrical energy. These pump system are also powered at great cost by diesel generators or require the construction of expensive transmission and distribution lines, Brown said.

Housed in a 20-foot sea container, the Power Cube is a mobile, scalable, reliable and efficient low cost alternative. It’s a microgrid, which is basically a miniature version of a larger utility grid, that connects renewable energy sources, such as wind and solar, to an electrical load like a pump or refrigeration units. The microgrid has a lithium titanate battery bank, inverters, variable speed drive and reserve storage tanks, Brown said. If wanted, the microgrid could connect to Hawaii Electric Light Co.’s grid or utilize bio-diesel power, he added.

The North Kohala system’s 100-kilowatt wind turbine powers the variable speed and 100 horsepower pump, he said.

There are many possibilities for this prototype, including being used at water treatments facilities in Hawaii or in Third World countries, where infrastructure is scarce and water resources are lacking. The goal is to commercialize the system, which can be purchased outright or leased. Its design life expectancy is approximately 20 years, Brown said.

The system took roughly 18 months to build, and “it’s a wonderful thing seeing an idea that benefits the planet and truly makes a difference to the community become a reality,” he said.

For more information, call Gen-X at 220-8538 or visit