Oahu-Maui Grid Tie

Hawaii spends billions of dollars every year on imported foreign oil for electricity generation.  This puts our state at the mercy of unstable oil prices and threatens our energy security, not to mention the damage caused to the environment by spewing carbon and other pollutants into the air.  To reduce our dependency on petroleum, Hawaii is pursuing clean energy alternatives that will benefit ratepayers.

As outlined in the State Energy Policy’s second directive, connecting the islands through integrated, modernized grids is critical to meeting our energy goals.

AN OAHU-MAUI GRID TIE IS IN THE PUBLIC INTEREST.

The Hawaii Public Utilities Commission (PUC) is investigating whether an Oahu-Maui Grid Tie is in the public interest (Docket No. 2013-0169.  View at PUC’s Document Management System (DMS).  The Department of Business, Economic Development and Tourism (DBEDT) supports an interisland transmission cable connecting Oahu and Maui grids.  As the state’s Energy Resources Coordinator, DBEDT believes an Oahu-Maui grid tie is in the public interest.

WHAT ARE THE BENEFITS?

Benefits to Ratepayers on Oahu and Maui Island

  • Reduced electricity rates of up to 0.6-cents per kilowatt hour
  • Overall net savings on both islands of up to $423 million over a 30-year period (2020-2050)
  • More stable electricity rates due to reduced exposure to oil pricing volatility

Benefits to the Environment

  • Reduced pollution from less oil being burned by conventional fuel electric generating units
  • Allows the retirement of old, inefficient petroleum-based power plants
  • Lowers cost of environmental compliance and carbon pollution

Benefits to Renewable Energy Goals

  • Increased utilization of high-efficiency renewable energy development that can be operated with less or even no curtailment
  • Helps the state meet and exceed its mandated renewable energy goals
  • A key, long-term component to achieving a modernized grid
WHAT IS A GRID TIE AND HOW IT IS DIFFERENT FROM PREVIOUS PROPOSALS?
  • Current Grid Tie – The current investigation is looking at a grid tie, a two-way connection between two previously distinct, separate electrical grids to create one unified system between Oahu and Maui Island.  By unifying the grid and sharing resources, the utility will be able to operate more efficiently with less system redundancies, allowing more renewable energy penetration and the shutting-down of old, inefficient petroleum-based power plants.
  • Past Gen Tie – Previous interisland transmission cable projects proposed a one-way cable, or a generation (“gen”) tie, which would have taken energy generated from one or more islands to feed into Oahu.
HOW DID DBEDT COME TO THESE CONCLUSIONS?

In response to the PUC’s investigation on whether an Oahu-Maui grid tie is in the public interest, the state analyzed various scenarios based on a Hawaiian Electric Company integrated resource planning (IRP) scenario called “Stuck in the Middle.” This scenario was chosen because it leads to conservative results regarding the benefits of the grid tie and its assumptions are publicly available. Had DBEDT chosen other highly-plausible scenarios or assumptions, the resulting benefit estimates would have been much greater.

DBEDT’s full analysis and comments, dated September 9, 2013, can be found on the PUC’s Document Management System (DMS), Docket No. 2013-0169.  Click on the “Documents” tab.

More information can be found on DBEDT’s Interisland Cable Frequently Asked Questions (PDF).

For information and data on renewable energy and energy efficiency in Hawaii, download the Hawaii Energy Facts & Figures, May 2017 Edition.