Data centres in future European energy systems—energy efficiency, integration and policy

Overview

End-use efficiency, demand response and coupling of different energy vectors are important aspects of future renewable energy systems. Growth in data centres is increasing electricity demand and creating a new electricity-intensive industry, and studies so far have focused mainly on energy efficiency. The paper contributes an assessment of the potential for energy system integration of data centres via demand response and waste heat utilisation, with a review of relevant EU policies. Waste heat utilisation is mainly an option for data centres close to district heating.

Waste-heat outlet temperature depends on cooling technology: air cooling typically gives 25-35 °C, liquid cooling up to 60 °C, and novel two-phase systems up to 90 °C. Fourth-generation district heating can run with supply temperatures of 45 to 55 °C. Stockholm Data Parks co-locates several data centres around a central heat-pump station that upgrades their waste heat for the DH network, reducing the DH company's reliance on a single operator. ERE is defined as (Total energy - Reused energy)/IT energy, against PUE = Total energy/IT energy, and is suggested instead of PUE to capture waste-heat use.

On demand response, the European Commission estimated EU-28 data-centre electricity use in 2015 at 78 TWh, equivalent to 2.5% of total EU electricity use. Danish data centres using about 500 GWh/year and 60 MW were estimated able to provide 22 MW of demand response, and European data centres could provide more than 10 GW of demand response in 2030. The analysis shows considerable potential for demand response and energy system integration.

The authors conclude that EU policy (Ecodesign, Code of Conduct, tax exemptions) has so far relied on carrots rather than sticks; such policies are in their nascent phase and mainly focused on energy efficiency through the voluntary Code of Conduct and criteria under the Ecodesign Directive. Limits: a policy and potential analysis; potential estimates rest on assumptions and are not measured implementation results.

Key points

1. Waste-heat outlet temperature depends on cooling technology: air cooling typically gives 25-35 °C, liquid cooling up to 60 °C, and novel two-phase systems up to 90 °C.
2. Fourth-generation district heating can run with supply temperatures of 45 to 55 °C.
3. Stockholm Data Parks co-locates several data centres around a central heat-pump station that upgrades their waste heat for the DH network.
4. ERE = (Total energy - Reused energy)/IT energy, against PUE = Total energy/IT energy; ERE is suggested instead of PUE to capture waste-heat use.
5. The European Commission estimated EU-28 data-centre electricity use in 2015 at 78 TWh, equivalent to 2.5% of total EU electricity use.
6. Danish data centres using about 500 GWh/year and 60 MW were estimated able to provide 22 MW of demand response, and European data centres could provide more than 10 GW in 2030.

Using it in design

• In waste-heat sales, set outlet temperature by cooling technology (air 25-35 °C, liquid up to 60 °C, two-phase up to 90 °C) and check heat-pump requirement against the district-heating generation (45-55 °C for 4G).
• Report heat reuse with ERE instead of PUE; PUE does not capture heat reuse.
• For demand response, assess backup generator and battery capacity as a grid service and plan the option of shifting workload in time or space.

Who should read it

Planners and policy specialists evaluating energy system integration (waste heat, demand response) of data centres and EU policy.

Document contents

1. Introduction
2. Data centre energy demand estimates
3. Energy efficiency
4. Waste heat utilization (outlet temperatures, district heating, ERE, Stockholm Data Parks)
5. Demand response (temporal and spatial workload shifting, on-site batteries and gensets)
6. EU policy landscape (Ecodesign, Code of Conduct, tax exemptions)
7. Conclusions

Related standards

• EU Code of Conduct for Data Centres
• EU Ecodesign Regulation (servers and storage)

Read the document

Publication details

Authors

Carolina Koronen; Max Åhman; Lars J Nilsson

Publisher

Energy Efficiency (Springer Science and Business Media LLC)

Year

2019

Volume

13

Issue

1

Pages

129-144

Document language

English

Source type

Scientific

Access

Open licence — downloadable

DOI

10.1007/s12053-019-09833-8

Licence

CC BY 4.0 — share with attribution

Licence evidence

doi.org

Citation