- AttributedToyobo MC · February 2024
- Reports completion, 500 m³/day production, and recovery above 65% Toyobo MC
- PublishedDOE-hosted final report
- Permeate produced during daily operating runs, June 2022–September 2023 DOE / NELHA final report
- MeasuredWater quality versus rate
- Less than 500 ppm TDS at low rates; 500–700 ppm at higher rates as extractor imbalance limited acceptable output DOE / NELHA final report
- Published100-hour go/no-go target
- Required >20 m³/hour steady state; the report states it was not achieved DOE / NELHA final report
- AttributedDaily production window
- Trevi's own account: a solar-thermal storage limitation held production to 4–6 hours per day Trevi project account
DOE Solar-Thermal Demonstration
NELHA
Kailua-Kona, HawaiiAt NELHA's HOST Park, the U.S. Department of Energy and NELHA funded a nominal 500 m³/day forward-osmosis plant running on process heat from an existing 2 MW solar-thermal array and thermal storage. Trevi engineered and integrated the plant; NELHA supplied the site and seawater infrastructure.
The project
Funding, Construction, and Operation
In 2018, DOE and NELHA defined a next-generation forward-osmosis system sized to a nominal 500 m³/day, paired with NELHA's existing 2 MW solar-thermal array and hot-water thermal storage at HOST Park in Kailua-Kona. Trevi was the main technology contractor and integrator.
The plant was built and operated from June 2022 to September 2023, documented in the DOE-hosted final report.
- Award
- DE-EE0008403 · $1,928,238 DOE award · $2,311,938 awardee cost share (DOE project listing)
- Site
- NELHA HOST Park, Kailua-Kona, Hawaii · Existing seawater intakes and a 2 MW solar-thermal array
- Nominal design
- 500 m³/day forward-osmosis system, proposed by DOE and NELHA
- Report period
- Operated June 2022 – September 2023 (DOE-hosted final report)
500 m³/day describes the project's design basis.
What was integrated
Four Connected Systems
The project tied Trevi's forward-osmosis plant into infrastructure NELHA already operated at HOST Park: feed seawater, membrane transfer, process heat, and final water handling in a single demonstration.
- 01
Seawater supply
NELHA's HOST Park intakes supplied feed seawater to the plant.
- 02
Forward-osmosis transfer and draw recovery
A membrane loop moved water across an osmotic draw; a separate stage recovered and regenerated the draw solution.
- 03
Solar-thermal heat and storage
NELHA's 2 MW concentrating solar-thermal array and hot-water thermal storage supplied process heat; a natural-gas-fired boiler in the plant's energy boundary at times ran alongside the solar system.
- 04
Final water handling and measurement
Permeate passed through final handling before sampling; the final report records handheld salinity measurements from operating runs.
Project sequence
From Award to Operating Plant
From funding through commissioning to documented results.
- 01
Fund and define
DOE award DE-EE0008403 provided $1,928,238, with $2,311,938 in awardee cost share, for a nominal 500 m³/day forward-osmosis design paired with NELHA's 2 MW solar-thermal array.
- 02
Design and fabricate
Trevi engineered the membrane trains, draw recovery, heat exchange, and controls around NELHA's site infrastructure and thermal source.
- 03
Install and integrate
The plant was installed at HOST Park and connected to NELHA's seawater intakes, solar-thermal array, and thermal storage.
- 04
Commission and operate
The plant operated from June 2022 to September 2023, producing permeate (DOE-hosted final report).
- 05
Measure and learn
Recovery rates at times exceeded 65%. The final report also documents a commissioning milestone that was not met, carried forward as project learning.
Published sources
Published Sources
The Toyobo account and the DOE-hosted final report are reported separately.