Solutions to Water and Power Availability that Challenge the Future of Data Centers

Overview

The paper starts from Singapore's resource baseline: about 606 million m3/yr of water and about 50 TWh/yr of electricity in 2019, with 2018 peak demand near 7,000 MW. A hypothetical 3 GW IT load is placed against it, comparing water-cooled and air-cooled chiller plants at 24 C supply air with StatePoint Liquid Cooling (SPLC) alone at 32 C SAT and SPLC with chiller trim.

On water, water-cooled chillers need about 1.9 L/kWh WUE and about 51 million m3 a year, while SPLC at 32 C SAT cuts that to about 1.09 L/kWh and 29 million m3. On energy, annualised pPUE at 24 C SAT is about 1.3 for water-cooled and about 1.4 for air-cooled chillers (6.8 and 9.8 TWh/yr), against about 1.12 pPUE and 2.3 TWh/yr for SPLC at 32 C.

As an efficiency measure, chiller COP is typically 3-7, SPLC 12-21 year-round, SPLC with water-cooled trim 8-16 and with air-cooled trim 6-14. At peak, 3 GW of IT on air-cooled chillers draws about 1,147 MW (16% of the national peak) versus about 800 MW water-cooled, and SPLC is far lower. The case study assumes water at about USD 2/m3 and power at about USD 0.10/kWh. The paper also describes SPLC operating modes and the membrane exchanger's water-quality benefits; the scenario is hypothetical and manufacturer-sourced.

Key points

1. Singapore: ~606 million m3/yr water, ~50 TWh/yr electricity (2019); 2018 peak demand ~7,000 MW.
2. 3 GW IT at 24 C SAT: water-cooled chillers ~1.9 L/kWh WUE and ~51 million m3/yr; SPLC at 32 C SAT ~1.09 L/kWh and ~29 million m3/yr.
3. Annualised pPUE at 24 C SAT: water-cooled ~1.3, air-cooled ~1.4 (6.8 and 9.8 TWh/yr); SPLC at 32 C ~1.12 and ~2.3 TWh/yr.
4. COP: chillers 3-7; SPLC 12-21; SPLC with water-cooled trim 8-16; with air-cooled trim 6-14.
5. Peak power: air-cooled chillers ~1,147 MW (16% of national peak) versus ~800 MW water-cooled.
6. Case prices: water ~USD 2/m3, power ~USD 0.10/kWh.

Using it in design

• In a site/sustainability module, estimate annual water (m3), WUE and cooling energy for alternative plant types at a chosen SAT, using local water and power tariffs.
• Flag sites where projected campus water or power use is a material share of local supply.
• Seed early-stage energy models with plant COP ranges by technology in the catalog.

Who should read it

Planners and sustainability leads choosing a large-campus site and cooling technology.

Related standards

• ISO/IEC 30134-9
• ASHRAE TC 9.9 Thermal Guidelines

Publication details

Authors

Philip LePoudre

Publisher

Nortek Air Solutions

Year

2021

Document number

597f

Document language

English

Source type

Manufacturer

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation