The problem
Gizo, in the Solomon Islands, is the kind of place desalination was supposed to help: surrounded by seawater, short on fresh water, and at the end of a fuel supply chain that makes every liter expensive. Conventional desalination needs either grid electricity or active heating — and the cost of water there is, mostly, the cost of that energy.
The DOE Marine Energy Collegiate Competition asks teams to put marine energy to work on real coastal problems. We chose to make water.
The reframe
The cost problem was really an energy problem — so the thermocline did the work twice.
The ocean already maintains a temperature gradient — warm at the surface, cold below the thermocline. That gradient is low-grade energy, unusable for most machines but exactly the kind of heat a membrane-distillation process wants. Instead of generating electricity to power a desalination plant, the platform harvests low-grade ocean-thermocline heat directly: warm surface water drives evaporation across the membrane, cold deep water pulls condensation. No grid connection. No fuel deliveries. The energy bill — the thing that actually sets the price of water in Gizo — falls out of the design.
Modeled output: 28,600 liters per day, fresh water for 1,430 people, with the projected levelized cost of water 51% below the Gizo baseline.
Design
The heart of the platform is a conductive-gap membrane-distillation module. My design contribution was its finned channel: a modular geometry that supports interchangeable fin configurations, so the team could test heat-transfer trade-offs in hardware instead of arguing about them in simulation.
Interchangeable fins turned a design argument into a test matrix. When the geometry is swappable, you don’t have to be right the first time — you have to be measurable.
Build & test
We built the lab-scale prototype and I led its testing. That end of the project — machining, sealing, instrumenting, running — is where the design either holds up or doesn’t.
It held up. The team won Best Build & Test honors against 27 teams at the DOE Marine Energy Collegiate Competition, a judgment specifically of prototype design and testing rigor.
Leading the team
Twenty undergraduate and graduate researchers, two DOE competitions running in parallel. I set MECC’s technical direction, drove the industry-mentor strategy, and aligned the Hydropower Collegiate Competition planning with its incoming lead. The budget — $21,000 in staged competition funding tied to proposal deliverables — I built and managed first, then deliberately delegated.
The work also traveled: we co-authored and presented “Utilizing Ocean Thermoclines for Water Desalination” at NCUR 2026, and ran three K-12 outreach events that put hands-on builds in front of 226 students.
Lessons
The project’s central lesson is the reframe itself: the most expensive part of a system is often an energy flow wearing a cost costume. Finding the gradient that’s already there — and using it twice — beat every version of the design that tried to fight thermodynamics head-on.
