HCTGS v41 Mexico — The Country That Has Two Oceans

Abstract Mexico holds 89.9 billion cubic metres of water a year under concession for consumptive use, three quarters of it agricultural. At a reference output of one million cubic metres a day per tower, that volume is 246 gravity-fed seawater cascade towers — a ceiling rather than a build order, and one that answers two questions at once: it is what full independence from a wet year would take, and it is also what it would take for every cubic metre the country uses to have changed phase on the way in, and therefore to carry no microplastic, no nanoplastic and no PFAS. Underneath the ceiling sit the numbers that carry the argument: 36 towers for the entire public supply, 188 for irrigation, and 14 to 22 for the share of national electricity now generated from imported gas — 189.6 TWh in 2024, with 94 per cent of power-station gas imported. Fifty to fifty-eight towers cover every tap in the country and all the power it makes from fuel landed by ship. For a 2075 case in which rainfall can no longer be counted on, the line is 460 towers, resting on five separately stated assumptions, which between 2030 and 2080 is nine to ten towers a year. The edition answers the question a Mexican reader asks first. The capital stands at 2,240 metres. One tower generates 24 to 36 kWh for each cubic metre it produces; lifting that cubic metre through four to five pressure stages, at a stated total head of 2,600 to 3,200 metres, costs 8 to 11. A third of the tower’s own generation carries the water up and two thirds go to the grid, or into hydrogen at the same capacity. The comparison is domestic: the Cutzamala system delivers 1.32 million cubic metres a day, which is 1.3 towers, and spends about USD 175 million a year on pumping alone — 9 to 26 per cent of what a single tower generates, with no generation on its own side of the ledger. Its treatment plant has run 43 years against a normal service life of 15 to 20, and was recapitalised in 2025 for another four decades. The machine is described as three coupled circuits: the thermo-mineral cascade at foot level, the tower on the steam side, and the product-water path. Heat is spent down a ladder from 2,200 °C specialist ceramic through the magnesium flame at 1,500–1,800 °C, a melt near 700 °C, the Mg–Cl circuit at 450–550 °C, pyrohydrolysis from 220 to 600 °C, process steam at 110 °C, the bulk circuit at 60 °C, to a dome at 4 °C. The magnesium flame never touches water; only the hydrogen burner runs submerged. At reference output the column carries 11,574 kg of steam a second, a latent duty of 26.1 GW, against purchased heat of 0.65–0.87 GW — an equivalent gain-output ratio of 30 to 40 against 6 to 15 for multi-stage flash — with a driving pressure difference of 14 to 19 kPa, condensation of 1 to 5 per cent at the cold core and 95 to 99 per cent in the descending shafts, and a residual stream of 12 to 60 m³/s. The demand side is stated in Mexican figures: 114 of 653 aquifers overexploited and 41 of Chihuahua’s 61 in deficit; 18 aquifers with recorded seawater intrusion; recharge of 512.8 against extraction of 993.23 million cubic metres in the metropolitan aquifer, a deficit of 480 million, which is 1.3 towers; ground descending 10 to 40 centimetres a year; leakage and unmetered supply of 23 m³/s in the Valley of Mexico, which is 2.0 towers; and the Rosarito plant at 0.19 and 0.38 of one tower. The price structure households face is set out alongside: tariff blocks of USD 0.25 to USD 1.48 per cubic metre, tanker water at USD 7 to USD 15, bottled water at USD 132 to USD 176 — multiples of 13 to 28 and 250 to 340 against the tariff. The document states one water quality for everyone, with any tiering in the delivery chain rather than in the water. Second-order effects are treated with their limits. Irrigation water is priced as a by-product because that is what it is, at 10 to 30 cents a cubic metre, which one tower’s output cannot carry alone and is not asked to. Land value moves with density rather than distance: the same 6.7 million people supplied by one tower occupy 1,334 km² at 50 persons a hectare or 133 km² at 500. Minerals are stated as capacity and never as revenue, and the architecture positions itself as a supplier rather than a competitor — the established producers in each field are the first partners, on one technical condition: that the melting, crystallising and refining happen at the cluster, where their reject heat at 30 to 60 °C returns to the cascade as feed preheat. A metal ladder of six rungs is stated as conditionals, each with the barrier that holds it and the condition under which it falls — titanium and zirconium sponge, aluminium alloying and steel desulphurisation, saltwater components, lightweight structures, magnesium as an energy carrier, and resorbable implants — against world primary magnesium production of about one million tonnes a year and 47 to 141 kt released per tower-year. One novel contribution is claimed. NC-MX-1, a two-stage cascade-matched thermal store: a chloride melt as the upper stage at 400 to 550 °C discharging into a sand or rock stage as the lower one, down to 110 °C and below, so that the melt’s cold end is held above its freezing range by the stage beneath it and the whole discharge curve is spent against a process that has eight temperature rungs. Both components are established separately; the series arrangement and its matching to the cascade are what is placed on the record. Twelve hours of a tower’s purchased heat is 92,000 to 122,000 tonnes of sand against 190,000 to 250,000 tonnes of melt, and the tower never pays the conversion loss that a storage plant selling electricity must. See full File here: https://doi.org/10.5281/zenodo.22851833 Further sections cover the oxygen minimum zone of the Gulf of California as the intake with the least entrainment and the destination for 0.8 to 1.3 Mt of surplus electrolytic oxygen a year per tower — counted once, burned, sold or sunk, with the N₂O hump stated as a design rule; the two coasts and the enclosed variant for operators buying continuity; magnesia, spinel and Sorel-class cement for ports and offshore structure; programmable mineral profiles for the coastal tourism industry; the vehicle industry, whose entire national process water is 2 to 4.5 per cent of one tower-year and whose real purchase is continuity and metal; and a comparison against the largest built power projects on earth, where eight to twelve towers equal the Three Gorges dam on one to two square kilometres of occupied ground. Financing is set out as five routes — anchor prepayment, a pension allocation where one per cent of Mexican pension assets is four to six towers a year, development-bank guarantees, export credit and land value capture — with commissioning governed by a fuel gate rather than a title gate: ownership transfers at start-up, and the operator carries purchased fuel at its own cost if the magnesium loop has not closed within twelve months of first fire. Part I states the case. Part II carries the same numbering with sources, stated assumptions, and the open quantity under each. The pilot is USD 10 to 15 million over two to three months, and everything it produces is published. Magnitudes are design estimates offered for independent assessment. Published as open prior art under CC BY-NC-ND 4.0; commercial use by separate agreement.