Unlike wind or solar, geothermal energy located deep below the earth's surface is always on.

But companies will often shy away from exploring new geothermal sites in Hawaii because of the state's strict environmental regulations, which cost both time and money.

On Thursday, a subcommittee of the state Environmental Council heard from potential geothermal developers about why the State Land Department should be allowed to waive certain environmental regulations.

"The cost and timelines of the current rules make it restrictive to explore in this state," said Bill Sherman, land manager for Ormat Technolgies, a Nevada based company that owns the 30 megawatt geothermal plant in Puna on the Big Island.

After hearing testimony, the seven member subcommittee approved three environmental exemptions for geothermal exploration. They include non-invasive testing and analysis, the issuance of leases on state or reserved lands, and the drilling of exploration wells.

If approved by the full 15-member Environmental Council May 17, the exemptions would allow the State Land Department to drop costly environmental assessments from geothermal exploration projects.

"This simply gives us the opportunity to point out an exemption for the environmental processes," said State Land Director William Aila. "There's still all of the other state, federal and county processes that have to be complied with."

The 30-megawattt Puna Geothermal Venture plant already produces 20 percent of the Big Island's energy needs. Allowing exploration wells to be dug more quickly and cheaply could lead to the construction of more plants.

Ormat is exploring the construction of a 50-megawatt geothermal plant on Ulupalakua Ranch in southern Maui. Meanwhile, Hawaii Electric Light Company opened a docket with the Public Utilities Commission May 1, asking for proposals to build a new 50-megawatt geothermal plant on the Big Island.

In his State of the State speech in January, Gov. Neil Abercrombie lobbied for more renewable energy output and mentioned the Big Island by name.