HVO: Volcano Giveth, and Volcano Can Taketh Away

***Update: The article was amended on July 1 to clarify that it would be the cable pathway on land and not the undersea portion of the cable that would be at risk from lava flows from Mauna Loa’s northeast rift zone.***

A bill establishing a regulatory framework for an undersea power cable was signed into law Wednesday by Gov. Neil Abercrombie.

Abercrombie’s administration has been pushing for the cable as a way to share electricity generated on the neighbor islands with Oahu, where the bulk of the state’s population lives.

The power sources discussed so far include wind farms on Molokai, Lanai and Maui, and geothermal energy on Maui and the Big Island.

However, scientists at the Hawaiian Volcano Observatory today said that there are potential problems with the latter concept.

They said volcanism, the energy that provides the energy tapped by Puna Geothermal Venture and possibly future plants, could also waylay plans to ship that power off-island.

In today’s edition of the weekly Volcano Watch column, HVO scientists said that the cable’s pathway would have to pass along the northeast flank of Mauna Loa, where there is a “significant likelihood” of lava inundation.

The column said in the past 200 years, there have been six eruptions on the volcano’s northeast flank. During that time, there have also been three eruptions in the lower east rift zone of Kilauea on which PGV is located.

“The possibility of an eruption in the geothermal resource or state-wide cable path within any 50-year period is between 60 and 90 percent,” HVO said.

The impact of an eruption at the site of a geothermal power plant could be severe, including the chance it might be buried deeply by lava, the scientists said. The result would be the loss of that power source “possibly for weeks, months or even years” until after the eruption ceased.

The private-public partnership that developed Hawaii’s first geothermal plant – the HGP-A plant located just above PGV – recognized that as a potential problem. When the plant was built in the early 1980s – around the time the current eruption of Kilauea began – its turbine-generator was built on skids so it could be moved in the event of a lava flow.

If an eruption should affect a large-scale geothermal facility providing power to other islands – a 2005 study suggested Kilauea could produce 500 megawatts or more – then the impact could be felt statewide, HVO said.

“As a community, we should explore all options in our quest for inexpensive, reliable electricity,” the column said. “There are down sides to the utilization of any energy source, and we must balance the negatives with the positives when making choices.

“This includes balancing the considerable benefits of geothermal resource development with the inherent volcanic risk of such development on active volcanoes,” it said.