Fab utility demand estimator

How it works

A fab's utilities are sized long before the first wafer. This tool estimates the electricity, ultrapure water, cooling, nitrogen and compressed air a fab will draw from its wafer starts, its number of layers per wafer, its EUV scanners and its cleanroom size, with every intensity open to your own figures. It gives average and peak power, annual energy, water intake with reclaim, gas flows, the cooling load and a yearly utility bill, and shows how each changes with wafer starts.

1. Wafer layer passes. Most process loads follow the number of times a wafer goes through a layer. Capacity in wafer starts a month times the layers per wafer gives layer passes a month; dividing by the hours in a month gives passes an hour at full capacity. The average runs at the loading you enter.layer passes per hour at full capacity = wafer starts per month x layers per wafer / hours per month average layer passes per hour = full capacity passes x loading
2. Process tools, sub-fab and EUV. Process tool and sub-fab (vacuum pumps, abatement, tool support) electricity are an energy per layer pass times the passes an hour. EUV is counted apart: each scanner has a throughput and utilisation, the scanners needed are the EUV passes an hour over what one scanner delivers, rounded up, and each draws its power all the time, a little less when idle.tool kW = layer passes per hour x kWh per layer EUV scanners = ceiling(EUV passes per hour / (wafers per hour per scanner x utilisation)) EUV kW = scanners x kW per scanner x (idle share + (1 − idle share) x loading)
3. Cleanroom air handling. A cleanroom recirculates its air through filters many times an hour. The airflow is the area times the air change rate times the height of the air path; the fans use a specific power in watts per cubic metre a second. A share of the air is fresh make-up air that must be cooled, dried or humidified, at an energy per thousand cubic metres that depends on climate. The air handling does not fall when loading falls, which is why a fab running part empty uses more energy per wafer.recirculated air (m³/h) = area x air changes per hour x air path height fan kW = air (m³/h) / 3,600 x specific fan power (W per m³/s) / 1,000 make-up air (m³/h) = recirculated air x make-up share; make-up kW = make-up air / 1,000 x kWh per 1,000 m³
4. Cooling and chillers. Nearly all the electricity inside the building ends as heat, which the chilled water plant removes. The heat load is the heat share times the process tools, EUV scanners, sub-fab and fans. One ton of refrigeration is 3.517 kW of heat. The chillers' electricity is the heat load over the plant COP, which here includes pumps and cooling towers.heat load kW = heat share x (tools + EUV + sub-fab + fans) cooling tons = heat load / 3.517 chiller kW = heat load / COP
5. Water, nitrogen and compressed air. Water use follows layer passes: litres per layer pass over the day. A share is ultrapure water; a share of the whole is met by reclaimed water and the rest is taken from the city. Nitrogen, compressed dry air and other bulk gases are normal cubic metres per layer pass; the plants that make nitrogen and compressed air, and the ultrapure water plant, add electricity at a specific energy per unit made. Exhaust is taken as equal to make-up air, which holds the room at a steady pressure.water m³/day = layer passes per hour x 24 x litres per layer / 1,000 city water = water x (1 − reclaim); ultrapure water = water x ultrapure share gas Nm³/h = layer passes per hour x Nm³ per layer; plant kW = Nm³/h x kWh per Nm³
6. Totals, overhead and cost. Overhead (offices, lighting, distribution losses) is a share of the rest. Average power uses the loading you enter; peak uses 100% loading plus a margin. The facility energy ratio, a PUE-like figure, is total site electricity over process tool and EUV electricity. On-site generation lowers the energy bought but not the peak, since it may not be running at the peak. Cost is energy, demand charge, city water, nitrogen and other gases at the tariffs you enter.total kW = (sum of loads) x (1 + overhead share) average MW = total at loading; peak MW = total at 100% x (1 + peak margin) annual GWh = average kW x hours per year / 1,000,000 facility energy ratio = total kW / (process tool kW + EUV kW)

Sources

The methods and default figures rest on these public sources. The wording here is our own; read the source for its full text.

• TSMC 2024 Annual Report, chapter 7, Corporate Sustainability (ESG) (opens in a new tab), Taiwan Semiconductor Manufacturing Company, 16 April 2025. Reported: total water use 129 million m³ in 2024 and 114 million m³ in 2023, and unit water use of 161.0 and 176.4 litres per 12-inch wafer-equivalent layer; 3,610 GWh of renewable electricity, 14.1% of the total, which implies about 25.6 TWh a year (our arithmetic).
• TSMC could account for 24% of Taiwan's electricity consumption by 2030 (opens in a new tab), DatacenterDynamics, 2024 (as seen in a search listing; the page itself could not be opened). Reported by the press from TSMC's figures: electricity of 27.7 kWh per 12-inch equivalent wafer mask layer in 2022 and 40.5 kWh in 2023, as 3 nm production ramped. Treat as reported, to be checked against TSMC's own report.
• EUV Lithography: A Power-Hungry Path to Innovation (opens in a new tab), TechInsights, Undated page, read 25 October 2026. Reported: up to 10.2 GWh a year for each EUV tool, about 1.2 MW on average, and about 11% of total fab electricity.
• Shining brighter: a 10x source power efficiency boost for EUV lithography (opens in a new tab), Bits&Chips (Paul van Gerven), 9 January 2025. Reported: up to 10.2 GWh a year per EUV scanner, 12.2 GWh for high-NA, and about 10% of fab electricity.
• Energy Performance of Cleanroom Environmental Systems (LBNL-49106) (opens in a new tab), Lawrence Berkeley National Laboratory (Tengfang Xu and William Tschudi), November 2001. Measured: recirculation fan power of about 0.17 to 0.21 W per cfm in efficient systems and 0.4 to 0.8 W per cfm in poorer ones; recommended air change rates of 300 to 540 an hour for ISO 4 and 240 to 480 for ISO 5.
• Semiconductor industry faces water, sustainability challenges (opens in a new tab), Manufacturing Dive (Michelle No), 5 August 2025. Reported: a fab can need up to 10 million gallons of ultrapure water a day, an average of 76% of withdrawn water goes to the manufacturing process, and TSMC replaced 12% of its water with reclaimed water in 2023.