Hawaii Utility Bills by Island: Electric, Water, Internet per Month

The Hawaii electric bill is the line item that surprises relocating households more than rent, groceries or car registration. Residential power in the islands costs roughly two and a half times the mainland average. The gap between islands is wide enough that the same three-bedroom house can cost $180 a month more to run on Lanai than on Kauai.

This article breaks down residential electricity charges per kilowatt-hour on every inhabited island served by a public grid. It then builds typical monthly bills for a one-bedroom condo and a three-bedroom house, with and without air conditioning. It adds water, sewer, propane and internet to reach a full monthly utility total, and closes with rooftop solar and battery math under the programs open in 2026.

Figures come from U.S. Energy Information Administration state data, utility tariff statements and county rate schedules. Electric rates in Hawaii move every month with fuel costs, so treat the numbers below as rounded, representative recent averages, not a quote for a specific address.

Why electricity costs so much in Hawaii

Hawaii has no interstate grid to lean on. Each island runs its own isolated system, and none can import cheap power from a neighbor when demand spikes or a plant trips offline. Every island must keep enough generating capacity to cover its own peak, which is expensive to build and maintain for small customer bases.

Imported oil still sets the price

Petroleum remains the largest single fuel source for Hawaii electricity, generating roughly two-thirds of the state’s power in recent EIA data. The fuel arrives by tanker, and its price flows straight into bills through a monthly energy cost adjustment. When world oil prices jumped in 2022, Oahu residential rates climbed past 45 cents per kWh within months.

The AES coal plant on Oahu supplied around 180 megawatts of relatively cheap power until it retired in September 2022. Its closure pushed rates higher again as oil-fired units filled the gap. Utility-scale solar and battery projects have since come online, but they are paid for through long-term contracts that also show up on the bill.

Fixed charges and small customer bases

Hawaiian Electric bills include a monthly customer charge, a minimum bill, and several riders covering renewable contracts, efficiency programs and grid upgrades. On Molokai and Lanai, with only a few thousand customers each, those fixed costs are spread across very few meters. That is the main reason those two islands post the highest rates in the country.

The Bureau of Labor Statistics Honolulu consumer price index tracks household energy as a separate component, and it has swung by double digits year over year during fuel spikes. Households budgeting for a move should plan around a range, not a single number.

Residential electricity rates by island

Four separate rate regimes cover the populated islands. Hawaiian Electric, still widely called HECO, serves Oahu, Maui, Molokai, Lanai and Hawaii Island, but each island grid has its own tariff. Kauai is served by the Kauai Island Utility Cooperative (KIUC), a member-owned co-op with its own rate structure and a much higher share of renewable power.

“All-in” means the total bill divided by kWh used. The customer charge, fuel adjustment and riders are blended into one effective rate at moderate usage of 500 to 600 kWh. A household using very little power will see a higher effective rate, because the fixed charges weigh more heavily on a small bill.

Oahu

Oahu has the largest grid, the most utility-scale solar and the most competitive internet market. Its residential rate has stayed in the low 40-cent range for most of 2025 and 2026, after peaking above 45 cents in late 2022. Honolulu condo dwellers typically see the smallest bills in the state simply because units are compact.

Maui, Molokai and Lanai

Maui runs a few cents above Oahu, and rate cases since the August 2023 wildfires have added uncertainty about how recovery and grid-hardening costs will be allocated. Civil Beat has covered those proceedings closely. Molokai and Lanai sit in a separate tier, with effective rates in the mid- to high-50-cent range.

Anyone considering the two smaller islands should read up on access and supply logistics first. The guide to getting to Molokai and Lanai explains why limited ferry and flight service shapes everything from fuel deliveries to the price of a new refrigerator.

Hawaii Island

Hawaii Island draws on geothermal power from the Puna Geothermal Venture plant, plus wind, hydro and solar, yet its rate still lands in the mid-40-cent range. Distances are long and the grid is thinly spread, which raises delivery costs. Climate varies sharply with elevation, so usage swings more here than anywhere else in the state.

Kauai

KIUC has pushed its renewable share well above half of annual generation, using solar paired with large batteries plus hydroelectric plants. That insulation from oil prices is why Kauai often has the lowest residential rate in the state. Co-op members also receive periodic patronage capital refunds, which slightly reduce the effective annual cost.

Typical monthly electric bills: condo vs house, with and without AC

Hawaii households already use less power than mainland ones. EIA data puts average residential consumption in the state at roughly 500 to 550 kWh per month, compared with about 860 kWh nationally. Mild temperatures, small homes and no heating account for most of the difference. Air conditioning is the swing factor.

The table below uses four usage profiles: a one-bedroom condo without AC at 275 kWh, the same condo running window or split units at 500 kWh, a three-bedroom house without AC at 550 kWh, and that house with central or multiple split units at 1,000 kWh.

The spread is striking. A family running AC in a three-bedroom house on Lanai pays about $180 more per month than an identical household on Kauai, or roughly $2,160 a year. Even between Oahu and Maui, the gap for a cooled house is about $50 a month.

What pushes a bill above these figures

Four loads account for most of the high bills new arrivals report. At Hawaii rates, each one can add $50 to $150 a month.

• Electric resistance water heaters, which can use 200 to 300 kWh monthly for a family of four.
• Pool pumps running 8 or more hours a day, often 300 kWh or more monthly.
• Older central AC systems with low efficiency ratings and leaky ductwork.
• Second refrigerators or chest freezers in hot garages, each adding 50 to 100 kWh.

State building code has required solar water heaters on most new single-family homes since January 2010, so newer houses usually avoid the first problem. Older homes and many condos still rely on electric tanks. Renters and buyers should confirm the water heater type on any listing.

Seasonality and microclimate

Cooling demand peaks from August through October, when trade winds weaken and humidity rises. Leeward areas such as Ewa Beach, Kihei and Kailua-Kona can see daytime highs near 90°F, while windward and upland homes often stay in the low 80s. January and February are the cheapest months for most households.

The month-by-month breakdowns of Oahu weather and Maui weather show how temperatures and rainfall shift through the year. On Hawaii Island the contrast is sharper. Homes in Waimea or Volcano, at 2,500 to 4,000 feet, rarely need AC, and some run a space heater on winter nights, as the Big Island seasonal guide describes.

Water and sewer charges by county

Water and sewer are billed by the four counties, not the state, and the structures differ substantially. Condo owners and renters often pay nothing directly, because water and sewer are bundled into the association maintenance fee. Single-family households receive a separate bill, typically every two months.

Ranges assume a household of three to four using 6,000 to 10,000 gallons per month. Landscape irrigation can easily double the water portion in dry leeward neighborhoods, especially from May through October.

Honolulu’s high sewer charge

Oahu households are often caught off guard by sewer costs, which can exceed the water bill itself. The City and County of Honolulu charges a fixed monthly base fee plus a usage charge tied to water consumption, reflecting years of federally mandated treatment plant upgrades. Current schedules are posted on the City and County of Honolulu site.

Catchment, cesspools and septic on the neighbor islands

Large parts of Hawaii Island, particularly Puna and Ka’u, have no county water lines. Homes there rely on rainwater catchment tanks. That eliminates the water bill but adds costs for filters, UV lamps, pumps and occasional tank relining, typically $300 to $800 a year. During dry spells, households buy hauled water at roughly $200 to $400 per load.

Most neighbor-island homes outside town centers use septic systems or cesspools rather than municipal sewer. State law requires cesspools to be converted by 2050, at a typical cost of $20,000 to $50,000. Buyers should confirm the system type before closing. The County of Hawaii posts water and wastewater information for its service areas.

Trash collection

Oahu funds curbside refuse pickup through property taxes, so most households see no separate charge. Maui County bills a monthly refuse fee for curbside service where it is offered. Hawaii County has no county curbside pickup: residents haul to transfer stations for free or pay private haulers roughly $40 to $60 a month.

Gas and propane costs

Hawaii has no mainland-style natural gas network. On Oahu, Hawaii Gas distributes synthetic and renewable natural gas through a utility pipeline in urban Honolulu. Everywhere else, including most Oahu suburbs, gas means propane delivered by truck to a tank or cylinder.

Delivered residential propane has generally run $5.50 to $7.50 per gallon in recent years, well above mainland averages near $2.50 to $3.50. Prices track oil and shipping costs, which is why ocean freight and fuel markets matter even for a kitchen stove.

• Gas range only: 3 to 5 gallons a month, about $20 to $35.
• Range plus clothes dryer: 6 to 10 gallons, about $40 to $70.
• Range, dryer and tankless water heater: 15 to 25 gallons, about $90 to $185.
• Tank rental, where the company owns the tank: often $5 to $10 monthly.

Many condos meter gas centrally and bill it through maintenance fees. For a house, a propane water heater may cost slightly less to run than an electric tank at Hawaii rates, but neither competes with a working solar water heater.

Internet, TV and phone service

Internet options in Hawaii have improved sharply since 2020. Spectrum provides cable broadband across most populated areas on every major island. Hawaiian Telcom has expanded fiber-to-the-home across much of Oahu and parts of the neighbor islands. Rural households increasingly use Starlink or fixed wireless from mobile carriers.

Promotional prices often expire after 12 months, and renewal pricing can jump by $20 to $30. Some plans add equipment fees of $10 to $15 a month. Remote workers should confirm fiber or cable at the specific address before signing a lease, since service maps can lag new construction.

Cable TV packages add $60 to $120 a month, though most new arrivals rely on streaming. Mobile plans are priced nationally, so a family plan costs about the same as on the mainland. Coverage gaps exist along the Hana Highway, in North Kohala and on parts of Kauai’s west side.

Full monthly utility totals by island

Combining the four categories gives a realistic budget line. The condo scenarios assume water, sewer and trash are covered by association fees, which is typical. The house scenarios include county water and sewer at the midpoint of each range, propane for a range and dryer, and internet at $70.

Condo totals add $20 for a gas range and $70 for internet to the electric bill. House totals add $55 for propane and $70 for internet, plus midpoint water and sewer of $193 on Oahu, $113 on Maui and Molokai, $88 on Hawaii Island, $108 on Kauai and $68 on Lanai. Trash fees, cable TV and phones are excluded.

Honolulu’s sewer charge wipes out Oahu’s electricity advantage for house dwellers. A three-bedroom house without AC costs more to run on Oahu than on Maui or Hawaii Island, and slightly more than on Molokai. For condos, electricity dominates, and the islands rank almost exactly by per-kWh rate.

A cooled house on any island now commonly exceeds $630 a month before a single phone bill. Those totals belong alongside food costs when comparing islands. The breakdown of grocery prices by island shows a similar pattern, with Molokai and Lanai at the top and Oahu generally cheapest.

Rooftop solar and batteries under the 2026 programs

Hawaii has the highest share of homes with rooftop solar of any state. The reason is simple: at 40 to 58 cents per kWh, self-generated power pays back faster than almost anywhere in the country. The rules have changed several times, though, and classic net metering closed to new Hawaiian Electric customers in October 2015.

Customer Self-Supply (CSS)

Under Customer Self-Supply, a system is designed so it does not export power to the grid. Solar output serves the home in real time, and any excess is either stored in a battery or curtailed. CSS offers faster interconnection review and avoids export rules entirely. The explainer on the HECO Customer Self-Supply tariff covers sizing and the minimum bill.

Smart Export

Smart Export pairs solar with a battery and allows exports only during evening and overnight hours, generally 4 p.m. to 9 a.m. Daytime exports earn no credit. Credited exports are valued well below the retail price, in the low teens of cents per kWh depending on island. The program rewards households that charge batteries at midday and discharge in the evening.

Battery incentive programs

Hawaiian Electric has paid upfront incentives to battery owners who commit to discharging stored energy to the grid during the evening peak. The original Battery Bonus paid per kilowatt of committed capacity, and successor demand-response programs follow a similar model, with amounts set by island and enrollment window. The Battery Bonus incentive explainer tracks how the payments have worked.

Kauai’s different rules

KIUC customers interconnect under co-op rules rather than Hawaiian Electric tariffs. Exports are credited well below retail, so most Kauai systems are designed for self-consumption with a battery. KIUC’s base rate is lower and its daytime grid is already heavily solar, so payback on Kauai typically runs a year or two longer than on Maui.

Tax credits after 2025

The federal 30 percent residential clean energy credit ended for homeowner-owned systems after December 31, 2025, which changed the math for 2026 buyers. Leased and power-purchase systems owned by installers may still qualify for commercial credits, which can make leases more attractive than before.

Hawaii’s renewable energy technologies income tax credit still applies: 35 percent of eligible solar costs, capped at $5,000 per system for a single-family home, claimed on Form N-342. Credit details and forms are available from the Hawaii Department of Taxation. Condo systems carry lower caps.

Solar payback math by island

The table models a three-bedroom house with AC using 1,000 kWh a month. It assumes an 8 kW array paired with one 13.5 kWh battery, installed for about $46,000 before credits, offsetting roughly 80 percent of grid purchases. Net cost after the $5,000 state credit is about $41,000, with no federal credit.

A solar-only system without a battery, sized for daytime self-consumption under CSS, costs far less: often $18,000 to $25,000 for 5 to 6 kW. It offsets a smaller share of usage, perhaps 40 to 50 percent, but payback can land between 6 and 8 years on Hawaiian Electric islands.

Several factors move these estimates. Battery incentive payments shorten payback by a year or more where available. Rising oil prices shorten it further, while falling rates lengthen it. Shaded roofs, windward cloud cover and inverter replacements around years 12 to 15 all extend it.

Production varies by location. A south-facing array in sunny Kihei or Kailua-Kona may produce 20 to 25 percent more than the same panels in rainy Hilo or Hanalei. The month-by-month rainfall data on Kauai’s wet and dry seasons shows how much cloud cover shifts between north and south shores.

How Hawaii households cut utility costs

Households that keep bills low tend to make the same handful of choices, and most cost little up front. The biggest gains come from avoiding electric resistance loads and limiting AC hours, not from small behavioral tweaks.

1. Choose housing with solar water heating or a heat pump water heater.
2. Favor windward or upland neighborhoods with steady trade winds if AC is unwanted.
3. Use ceiling fans and cross-ventilation before AC; fans draw about 30 to 60 watts.
4. Replace window units with inverter mini-splits, which use roughly 30 to 40 percent less energy.
5. Run pool pumps on variable speed and only during solar hours.
6. Apply for appliance and water heater rebates through the state’s Hawaii Energy program.
7. Ask landlords for 12 months of past utility bills before signing a lease.

Time-of-use rates are another lever. Hawaiian Electric’s time-of-use options price midday power, when solar floods the grid, well below the 5 p.m. to 9 p.m. evening peak. Shifting laundry, dishwashing and EV charging to midday can trim 10 to 15 percent from a bill.

Electric vehicle owners face a separate calculation. Charging 300 kWh a month at 42 cents adds about $126 on Oahu. That still compares favorably with gasoline, which has run well above $4.50 a gallon in Hawaii according to EIA fuel price data. Midday charging on solar makes the comparison far more lopsided.

Budgeting utilities before a move

A practical starting point is $200 to $380 a month for a condo and $450 to $800 for a house, adjusted by island and AC use. Households coming from mild mainland climates are often surprised that having no heating bill does not offset the higher per-kWh price.

Utility deposits are also common. Hawaiian Electric and KIUC may require a deposit of roughly two months’ estimated bills, often $200 to $400, for new accounts without local credit history. Spectrum and Hawaiian Telcom may run credit checks or charge installation fees of $50 to $100.

For broader context, the Census Bureau’s Hawaii QuickFacts lists median household income, housing costs and household size. Those figures help frame how large a share of a typical Hawaii budget utilities consume.

Frequently asked questions

What is the average Hawaii electric bill per month?

The statewide average residential bill runs roughly $210 to $230 a month, based on EIA consumption of about 500 to 550 kWh at an average rate near 42 cents. A small condo without AC can stay near $110 to $130, while a cooled three-bedroom house commonly reaches $400 to $580, depending on island.

Which Hawaiian island has the cheapest electricity?

Kauai usually has the lowest residential rate, around 40 cents per kWh, because KIUC generates well over half its power from solar, hydro and batteries. Oahu is a close second at roughly 42 cents. Molokai and Lanai are the most expensive, with effective rates in the mid- to high-50-cent range.

Is air conditioning necessary in Hawaii?

Many households live comfortably without AC, especially in windward, upland or breezy coastal areas. Leeward neighborhoods such as Ewa, Kihei and Kona can be uncomfortable from August through October, when trade winds weaken. Adding AC typically raises a monthly electric bill by $90 to $260, depending on home size and island.

Do condo fees in Hawaii include utilities?

Most Hawaii condo maintenance fees cover water, sewer and trash, and some include central gas, basic cable or central chilled-water AC. Electricity is almost always metered separately per unit. Buyers and renters should review the association budget to see exactly which utilities are bundled before comparing listings.

How long does rooftop solar take to pay back in Hawaii?

Solar-only systems under Customer Self-Supply often pay back in 6 to 8 years on Hawaiian Electric islands. Solar-plus-battery systems take roughly 7 to 11 years in 2026, since the federal homeowner credit expired after 2025. Payback is fastest on Molokai and Lanai and slowest on Kauai, where rates are lowest.

Can new solar customers still get net metering in Hawaii?

No. Hawaiian Electric closed traditional net energy metering to new applicants in October 2015, and KIUC has also closed retail-rate net metering to new members. New systems use Customer Self-Supply, which prohibits exports, or Smart Export, which credits evening and overnight exports at a reduced rate. Existing net-metered systems were grandfathered.

How much is internet in Hawaii?

Home broadband generally costs $50 to $90 a month for 300 Mbps to 1 Gbps from Spectrum or Hawaiian Telcom Fiber, after promotional pricing ends. 5G home internet runs about $50 to $70. Rural households often rely on Starlink at roughly $80 to $120 a month, plus hardware.

Why are Molokai and Lanai electric rates so high?

Each island runs a tiny standalone grid serving only a few thousand customers, mostly with diesel generation. Fuel must be barged in, and fixed costs for plants, lines and staff are spread across very few meters. The result is effective residential rates of roughly 56 to 58 cents per kWh.