What should I measure?
Measure total electricity use and water collected over the same period, such as 24 hours. Include the operating modes you actually use, including hot or cold dispensing where fitted. Note temperature, humidity, dispensing use and whether the room’s air conditioning is running.
- Electricity consumed: kWh over the observation period.
- Water collected: liters over that same period.
- Electricity rate: the applicable rate from your bill or utility guidance.
- Operating context: room conditions and selected dispensing modes.
How do I calculate electricity cost per liter?
Electricity cost per liter = kWh used × USD/kWh ÷ liters collected. Daily electricity cost = daily kWh × USD/kWh. A 30-day estimate multiplies the measured daily cost by 30 and assumes the same use and conditions throughout that period.
For an arithmetic example only, 3 kWh used while collecting 6 liters gives 0.5 kWh per liter. If the entered rate is 0.40 USD/kWh, electricity is 0.20 USD per liter and 1.20 USD for that measured day. These inputs are illustrative; they are not an AquaAloha performance test or a current Hawaii tariff.
Which Hawaii electricity rate should I use?
Hawaiian Electric publishes average electricity prices separately by island and customer class. Published annual averages provide context, while your applicable bill rate is the better input for a personal estimate. Rates and bill components can change; check your utility or bill rather than using a fixed website number as a current tariff.
The calculator starts with the published 2025 Hawaii Island residential average of 45.81 cents/kWh and labels it as historical. Replace it with your own rate. An estimate may need adjustment for fixed charges or other bill components that do not vary with equipment use.
What does this calculation leave out?
The calculation covers electricity only. It excludes filter sets, maintenance, equipment cost, freight and installation. It also does not predict water output. Compare those separate costs and measured results when assessing whether the equipment fits your needs.
For emergency planning, include stored water and an appropriately sized backup power source. The unit requires electricity; a daily capacity rating alone does not establish availability during an outage.
Sources & reference scope
AquaAloha prepared this guide from its supplied product documentation and the references below. Ratings and packing references apply to their stated equipment versions; this guide is not an independent installation test.