New method turns ocean water into drinking water, without waste

Nature of the claimed breakthrough

• Thread notes this is a University of Rochester solar-thermal desalination approach using a specially textured “black metal” surface.
• Key lab result cited: ~10 L/m²/day freshwater plus ~0.38 kg/m²/day salt under test conditions, with desalinated water below WHO/EPA salinity limits.
• Core novelty: capillary structure that moves salt away from the evaporating surface to a passive region, aiming to avoid fouling and allow solid-salt collection.

Brine, salt, and the “no waste” claim

• Many commenters dispute “without waste,” arguing solid salt piles are still waste and likely exceed any realistic market for salt.
• Others counter that solid salt is easier to manage than brine in some contexts and can at least avoid local “death zones” from concentrated discharge.
• Debate over whether crystalline salt disposal is actually harder than diluting brine and returning it to the ocean.

Energy efficiency and comparison to existing tech

• Several point out desalination has a thermodynamic minimum; reverse osmosis (RO) is already ~2–4× that limit and fairly efficient.
• Some argue the real comparison should be: solar thermal panels vs. using the same area for PV powering RO.
• Others stress economic and operational simplicity may matter more than peak energy efficiency, especially for low-skill, distributed setups.

Feasibility, scaling, and materials

• Strong skepticism that a lab-scale glass setup with femtosecond-laser-treated metal will scale cheaply or robustly.
• Concerns about salt slowly coating the active surface, fragility of nano-structured coatings, cleaning logistics, and need for complex enclosures or cooling.
• Prior “clog-free” solar desal prototypes (including from other universities) are noted as having little visible follow-up.

Byproducts and mineral recovery

• Some see potential value in solid salt for recovering magnesium, lithium, and sulfate, possibly offsetting costs.
• Others emphasize extraction is chemically and energetically nontrivial; cheap mined ores still dominate.

Environmental and ocean impacts

• Long subthread on brine toxicity: coastal discharge can create local dead zones, especially in shallow or semi-enclosed seas.
• Counter-argument: with sufficient dilution, deep/offshore discharge, or mixing with sewage/fresh seawater, impact can be negligible; this is framed as a solvable engineering problem.
• Disagreement over whether such mitigation is routinely done vs. ignored by cost-cutting operators.

Alternatives and broader context

• Some argue improving rainwater capture, groundwater management, and wastewater treatment is often cheaper than desal.
• Dehumidifier/“water from air” schemes are discussed and largely dismissed as energetically and volumetrically inefficient compared to desal.
• Political/economic obstacles (NIMBY opposition, lack of infrastructure investment, cost of nuclear vs. solar) are cited as bigger barriers than physics.

Meta: skepticism of university press releases

• Multiple comments criticize exaggerated titles and claims like “no waste,” urging more rigorous, less hype-driven communication from universities.