O‘ahu
Map of O‘ahu with icons representing existing renewable energy generation, including a waste-to-energy plant near Honolulu, rooftop PV installations distributed island-wide, and an ocean energy project at Kaneohe Marine Base on the island's southeast shore.
As Hawai‘i's commercial center, O‘ahu has the largest population of the Hawai‘ian islands and therefore faces the greatest challenge for matching local clean energy resources to local energy demand.
At the same time O‘ahu also has the greatest potential of any island for energy savings. O‘ahu could meet a significant portion of its energy needs through major energy-efficiency, solar, wind, and municipal solid waste initiatives. With a concerted effort to retrofit existing homes, businesses, and public buildings—as well as adoption of increasingly aggressive building codes that save energy in new buildings—O‘ahu could maintain its demand level over the next 20 years even as its economy and population grow.
Clean Energy on O‘ahu
O‘ahu is served by the Hawai‘ian Electric Company which has 1,670 megawatts of capacity. Most of the energy it provides to its customers is oil based, but approximately 5% is renewable energy, including
- Rooftop PV installations
- A municipal solid waste combustion generating plant (46 megawatts).
One proposal would expand the solid waste combustion facility for an additional 17 megawatts of waste-to-energy capacity, and various other renewable energy projects are under consideration by the utility as well. However, because O‘ahu does not have enough renewable resources, it will need to import energy to meet a significant percentage of its energy needs through clean energy. One option that is currently under study would be to import electricity by undersea cable from major wind projects on neighboring islands.
Additional Renewable Resources
Although only 10% of the energy consumed on O‘ahu comes from renewable energy, the island does have additional renewable resources that could be developed to help meet its demand.
Wind Energy
Wind offers the greatest near-term potential for meeting O‘ahu's electrical needs, although public support could be a crucial factor. Land near Kahuku, now owned by the U.S. Army, previously hosted a 12-megawatt wind farm. Approximately 30 megawatts of wind power are currently proposed for O‘ahu.
Ocean Energy
Although not currently commercial, ocean energy projects, particularly ocean thermal energy conversion (OTEC—steam generation by means of temperature differential between warm surface waters and cold waters at depth) could potentially be an additional energy source for O‘ahu and for Hawai‘i generally. One company is pursuing a 5- to 10-megawatt OTEC pilot plant on O‘ahu, which it hopes will serve as a model for building 100-megawatt plants.
Solar Energy
Sites for commercial-scale concentrating solar power or PV generating plants are relatively limited on O‘ahu due to land constraints. Rooftop PV is slightly more expensive than the commercial scale option, but has an advantage in that solar panels are built on top of existing buildings and infrastructure. Rooftop PV installations are already common on O‘ahu homes and businesses, due in large part to incentives provided under the 2008 Solar Roofs Act. For O‘ahu to reach its clean energy goals, thousands of additional rooftop PV systems will likely need to be installed across the island.
Biofuel
To help meet its ground transportation fuel needs, O‘ahu could readily develop biofuel production facilities. O‘ahu has some biomass and waste resources that could serve as biofuel feedstocks. Although it is not yet commercially available, algae-to-biofuel technology could also contribute to O‘ahu's clean energy portfolio in the future. As with electrical generation, however, O‘ahu would likely need to import biomass from neighboring islands to supply a significant portion of its transportation fleet with clean energy. Plug-in hybrid electric vehicles (PHEVs) and electric vehicles could also play a role on O‘ahu once they become commercially available, and studies are under way to determine how such vehicles could be best integrated with the island's grid and infrastructure. In addition, developing renewable energy resources to power alternative-fuel vehicles is essential if such vehicles are to become a part of O‘ahu's clean energy future.
