Oʻahu: Waste to Energy

Through incineration, Oʻahu’s H-POWER facility, working in tandem with recycling, is making a significant impact on the City and County of Honolulu's goal of reducing the amount of waste going to Oʻahu’s landfill. In 2017, more than 700,000 tons of municipal solid waste was processed through Oʻahu’s H-POWER facility, of which 507,000 tons was converted to electricity, over 22,000 tons of metal were extracted for recycling, and the remaining 170,000 tons consisted of non-combustible material that was sent to the landfill.

H-POWER reduces the weight of waste by 75% and the volume of waste by 90%. This has extended the life of the landfill by saving hundreds of acres of landfill space. Plus, virtually 100% of the ferrous and nonferrous metal mixed with municipal solid waste is recovered for recycling (see below for data on Recovered Metal).

Note: Tonnage data is gathered from independently certified scales.

Total Waste Converted to Energy

Figure 1: Total tons of waste converted to energy (Source: ʻŌpala)

In 2017, H-POWER converted nearly 508,000 tons of waste into electricity, effectively diverting that material from Oʻahu’s landfill. Moreover, working in tandem with recycling, H-POWER was able to divert 75% of Oʻahu’s solid waste stream from disposal at the landfill. Oʻahu’s 75% landfill diversion rate is up from about 68% in 2012 and 62% in 2009. As municipal solid waste rates continue to rise, the City expects an increase in the amount of waste sent to H-POWER and the amount of electricity the facility is able to generate, further reducing the island's dependence on foreign oil for its energy needs.

Ash + Residue

Figure 2: Thousands of tons of ash + residue disposed to the landfill (Source: ʻŌpala)

At H-POWER, ash is produced as an end product of the combustion process. It consists of bottom ash (coarse in size) and fly ash (finer particles). Bottom ash is screened through a drum magnet and eddy current separator for ferrous and non-ferrous metal recovery. Both bottom and fly ash are containerized and transported to the landfill for disposal.

Residue consists of wet organics such as food waste and other non-combustibles such as sand, dirt, grit, glass, and rocks. This material is removed through a trommel screening process because of its low energy value. Although residue is currently being disposed at the landfill, initiatives are being considered to further reduce the amount of residue.

Recovered Metal

Figure 3: Tons of recovered metal diverted from the landfill to recycling (Source: ʻŌpala).

H-POWER’s pre-processing system uses magnets to pull ferrous metals, such as steel, from the waste stream prior to incineration. Eddy current separators are used to extract non-ferrous metals, such as aluminum and copper, from the ash. This system diverts over 22,000 tons of metal to recycling annually.

Fossil Fuel Imports Avoided

Figure 4: The above graph represents the amount of fossil fuel (petroleum) that Hawaiian Electric Company (HECO) would have to import to generate the same amount of electricity that H-POWER generates with waste. Quick fact: Burning one ton of mixed Municipal Solid Waste produces roughly the same amount of electricity as burning one 42-gallon barrel of petroleum. (Source: State of Hawaiʻi and Hawaiian Electric Company.)

Total Electricity Generated from Waste

Figure 5: The above graph shows the total amount of electricity produced by H-POWER and sold to HECO through a joint power purchase agreement. The State counts the electricity generated at H-POWER towards its Renewable Energy Portfolio Standards goal (40% renewable energy by 2030), which includes other renewables, such as residential and commercial solar panels, biofuels, wind, hydro, geothermal, and biomass. (Source: State of Hawaiʻi and Hawaiian Electric Company)

H-POWER’s CONTRIBUTION TO OAHU’S ENERGY GRID

Figure 6: The above graph shows the percentage of H-POWER's contribution to Oahu’s energy grid. In 2016, the amount of energy produced at H-POWER contributed to 6.9% of HECO’s grid. By reducing our energy consumption, we are increasing H-POWER’s share of energy on the HECO grid, which translates to buying less and burning less imported fossil fuel. (Source: State of Hawaiʻi and Hawaiian Electric Company)

More Information

To learn more about H-POWER and its success of diverting hundreds of thousands of tons of waste from Oahu's landfill each year, visit the following websites: http://www.opala.org/solid_waste/archive/facts2.html and http://www.covanta.com/en/facilities/facility-by-location/honolulu.aspx

SDG 12 - Responsible Consumption and Production
Ensure sustainable consumption and production patterns
SDG 17 - Partnerships for the Goals
Revitalize the global partnership for sustainable development