Written by: Dennis O’Donnell

Did you know that the State of Hawai’i has set an ambitious goal to achieve 100 percent clean energy by 2045?!!

To progress towards accomplishing that mission, the next step of The Hawaii Clean Energy Initiative (HCEI) is to meet the state’s energy needs from 70% clean energy by 2030.

What are some of the ways that this unprecedented target can be reached? 

SUN

Solar thermal systems (including solar water heaters) are some of the most popular green-energy sources, and use the Sun’s energy to heat water for residential and industrial use.

Tens of thousands of solar water heaters are used in residences throughout Maui, reducing utility costs for users by eliminating the need for traditional grid-powered water heaters.

Photovoltaic (PV) systems are also increasing in popularity, as they use the power of the sun shining on to solar cells and causes a voltage differential (photo voltaic) which generates direct electric current to be generated. Thousands of photovoltaic systems are in use on Maui. Some generate power for use on-site (such as on residential, commercial, and other buildings) in systems that are known as distributed energy resources, while other (larger) systems generate power that is provided directly to electric utilities to power the grid.

WIND

Onshore Wind, or wind that is sited on land (ie Windmills) accounted for 21% of total energy produced on Maui in 2021 from the three large wind farms built on the island. Onshore wind has not been a desirable technology in areas where there are large populations of endangered bird species.

Offshore wind, or wind energy that is sited in the ocean, has not yet been developed in Hawai‘i and there is currently no timeline or specific plan to develop offshore wind in Hawai‘i’s waters.  With the advancement of floating turbines, offshore wind has become more feasible for use in Hawaiʻi. Unfortunately, due to the volcanic formation of the islands, the ocean depth drops steeply off the coastline, making fixed-structure turbines (or structures that are mounted on the seafloor) infeasible. If developed, offshore wind facilities would be a floating turbine design with transmission by undersea cable.

BIOENERGY

Biofuels

Pacific Biodiesel (www.biodiesel.com). The founders of Pacific Biodiesel, Bob and Kelly King, are farming sunflowers and other crops at their farm on Maui, showcasing a community-based model of sustainable agriculture, renewable fuel and food that is helping Hawaii achieve a clean energy future.

Biomass

Biomass is plant and animal matter and includes energy crops, wood, grasses, algae, vegetable oils, and agricultural and municipal wastes.

GEOTHERMAL

The Maui County Energy Alliance estimates that Maui might have 140MW of geothermal generating potential. The map below shows the identified Hawaii Geothermal Subzone.

Heated water from deep underground (geothermal wells are typically 5,000 to 10,000 feet below the ground’s surface) flashes into steam to drive a turbine. Then, in a second stage, the hot water condenses after passing through the turbine and heats a working fluid which has a boiling point lower than water. This second fluid drives a second turbine. The cooled geothermal water is then returned to the underground reservoir where it is reheated and reused. All fluids (the geothermal water and working fluid) are enclosed and not released into the environment.

HYDROPOWER

Flowing water — in Hawai‘i’s streams, rivers, reservoirs, pipes, and irrigation ditches — can be used to generate electricity. Hydroelectric facilities were among the first power plants in the islands, dating back to the late 1800s. Some of Hawai‘i’s existing hydroelectric plants date back to the early 1900s and have been maintained and upgraded to continue producing power. Currently, only the islands of Kauaʻi, Hawai‘i, and Maui have operating hydroelectric plants.

OCEAN

The ocean holds a great deal of the Earth’s energy — the Sun heats the surface, wind creates waves, and tidal forces exerted by the Sun and the Moon create tidal fluxes. Hawai‘i has significant wave and ocean thermal resources but minimal potential for tidal energy due to its relatively mild tidal changes. Most potential technologies that would harness ocean energy resources are in early pilot stages and have not yet been commercialized.

Thermal Energy (heat)

Two major ocean thermal technologies are of interest in Hawai‘i: seawater air conditioning (SWAC) and ocean thermal energy conversion (OTEC). Both rely on the fact that the deep ocean is significantly colder than the tropical surface. Thanks to the volcanic nature of Hawai‘i’s islands rising from the seafloor, this deep cold water is close to shore in many locations.

Marine Hydrokinetic Energy (motion – wave or tidal)

Marine hydrokinetic (MHK) technologies tap the kinetic energy of the ocean — the energy carried by moving water. Most typically, the ocean’s motion is converted to useable electricity by a device that either spins as the water flows past it or bobs up and down in the water. This means MHK facilities can generate more electricity from the oscillating (short period) rough seas created by trade winds than the slow and spread out (long period) swells that generate the famously large waves in Hawai‘i. Therefore, Hawai‘i’s relatively consistent trade winds are attractive for MHK developers. 

So as you can see, because of the Hawaiian Island’s unique geographic location, there are many options available to help make the Hawaii Clean Energy Initiative 2045 goal attainable!

Aloha,
Dennis O’Donnell
Romvari Realty
dennis@romvari.net
808-280-6596