How Much Water and Argon Does an Ingot Plant Consume?

The short answer

Two utilities after electricity decide whether an ingot-wafer site works: the argon that shields every crystal puller and the water that cools it and cleans the wafers. Both are continuous, both scale with the tonnes of silicon grown, and both are routinely underestimated at the site-selection stage.

For a 1 GW M10 TOPCon plant, this guide's worked example lands at roughly 1,700 tonnes of argon a year before recovery and roughly 1.5 to 2 million litres of water a day, which matches the order of magnitude of an announced Indian project. The sections below show the working so that a project can replace each assumption with its own.

Where the per-kilogram figures come from

The most complete public inventory is the IEA PVPS Task 12 report Life Cycle Inventories and Life Cycle Assessments of Photovoltaic Systems (T12-19:2020). Its unit process table for Czochralski single-crystalline silicon lists, per kilogram of crystal, 1.0 kg of liquid argon, about 5.09 cubic metres of cooling water, about 4 kg of deionised water and 32 kWh of electricity. For wafer production it lists about 57 litres of water per square metre of single-crystalline wafer.

Two cautions apply. The argon and water entries draw on data collected for the status of 2011, so they describe an older generation of pullers, and the inventory itself treats them as estimates with uncertainty ranges. They are the best public anchors available, not current equipment specifications.

Argon: a cross-check from flow rates

Argon is fed continuously over the melt to carry away silicon monoxide, as explained in the argon and vacuum systems guide linked below. A 2020 paper in Modern Electronic Materials by Kritskaya and co-authors gives conventional argon flows of 50 to 80 normal litres per minute per growth process, and proposes a two-flow design using about 15 to 20.

At an illustrative 60 normal litres per minute a puller uses about 86 normal cubic metres a day. At argon's density of about 1.784 g per litre at standard conditions, that is roughly 150 kg of argon a day. A puller producing an illustrative 150 kg of crystal a day is then at about 1 kg of argon per kilogram of silicon, the same order as the inventory. Lower-flow hot zones and larger charges push the ratio down; long stabilisation and meltback push it up.

Worked example: argon for 1 GW

The power-consumption guide in this series takes about 1,680 tonnes of crystal a year for 1 GW of M10 TOPCon, from the ITRPV 2026 figure of about 1.68 g of polysilicon per watt, treating that tonnage as crystal grown, a simplification. At 1 kg of argon per kilogram, that is about 1,680 tonnes of argon a year, roughly 4.6 tonnes a day.

In gas terms that is about 940,000 normal cubic metres a year. As a liquid, at about 1.4 kg per litre, it is around 1,200 cubic metres a year, or a little over 3 cubic metres a day delivered into on-site cryogenic storage. If an argon recovery system returned an illustrative 75% of the gas for reuse, within the 70 to 80% range one commercial supplier cites, fresh purchases would fall to roughly 420 tonnes a year.

• Fresh argon, no recovery: about 1,680 t a year, roughly 4.6 t a day (illustrative)
• Gas volume: about 940,000 Nm³ a year at 1.784 kg per Nm³
• Liquid volume: about 1,200 m³ a year at about 1.4 kg per litre
• With an illustrative 75% recovery: about 420 t a year of make-up argon

Water: cooling duty versus water drawn

Crystal pullers are water-cooled machines: the chamber walls, the heat shield region and the power supplies all reject heat into a cooling loop. The inventory's 5.09 cubic metres per kilogram, applied to 1,680 tonnes, is about 8.5 million cubic metres a year, or roughly 23 million litres a day of cooling duty. No plant draws that from a municipal supply. The loop is closed and recirculated through cooling towers or chillers, and what the site actually takes in is make-up water for evaporation, drift and blowdown.

The inventory assumes 5% of cooling water and 10% of process water evaporate. On that basis the crystal-growth step loses about 255 kg of water per kilogram of silicon, or about 1.2 million litres a day at 1 GW. That is the order of the make-up a recirculating system needs, and it is the number to compare with a site's water allocation.

Water: wafering and cleaning

Diamond-wire slicing uses water-based coolant, and the wafers are then degummed, cleaned and rinsed. At the inventory's 57.4 litres per square metre of single-crystalline wafer and about 134 million M10 wafers a year, roughly 4.4 million square metres, wafering needs about 250,000 cubic metres a year, or about 0.7 million litres a day. Thinner wafers, coolant recycling and cleaning-line design all move this figure.

Added to the crystal-growth make-up, the example lands at about 1.9 million litres a day before domestic use and any in-house recycling, inside the order of magnitude of the announced benchmark below.

An Indian benchmark

In December 2025 Energetica India reported that ReNew's planned 6 GW ingot-wafer plant at Rambilli in Andhra Pradesh would require 95 MW of uninterrupted power along with 10 MLD of water. Divided across 6 GW, that is about 1.7 MLD per gigawatt. It is an announced requirement for a specific project, not a measured consumption, and it covers that project's own scope and design, but it is a useful public reference point.

The practical lesson is that a gigawatt-scale ingot-wafer plant needs a dependable industrial water source in the low millions of litres a day, an effluent route for slicing and cleaning water, and a cooling-tower system sized for continuous duty in Indian ambient conditions.

What changes the numbers

Most of these are fixed when the site, the puller and the cooling system are chosen, which is why water and argon belong in the equipment specification rather than in the utilities budget after the order.

• Argon recovery: a recovery and purification unit can cut fresh argon purchases substantially
• Hot-zone and flow design: lower-flow gas guidance reduces argon per kilogram
• Charge size and recharging: more silicon per hot cycle means less argon and cooling per kilogram
• Cooling system: tower versus chiller, cycles of concentration and climate decide make-up water
• Wafer thickness and coolant recycling: thinner wafers and recycled slicing coolant cut wafering water
• Wastewater reuse: treating and returning process water lowers fresh intake

Every plant is different

The figures above are a starting point for site and utility conversations, not a design basis. JRST Technology's Phase 1 blueprint builds a project-specific utility balance, argon supply and recovery options, cooling-water and make-up requirements, and effluent routes alongside the machine list and site, and the project estimator at jrsttechnology.com/estimate is the place to start.