Dynamic Modelling of Data Center Waste Heat Potential Integration in District Heating in Latvia

Overview

As demand for data centres has increased rapidly, so has their electricity consumption, and most of the electricity consumed, including cooling, is eventually dissipated as heat released to the atmosphere without useful application. The study analyses the existing potential of waste heat recovery from data centres in Latvia and proposes a system-dynamics modelling approach to evaluate the future impact of waste heat on national heat supply. For each site, heat-pump COP, the energy reuse factor (ERF), distance to the nearest district heating (DH) network and simple payback were computed.

For the COP calculation, data-centre outlet (source) temperature was assumed to be around 18.7 °C and the required DH inlet temperature 65 °C, using the Lorenz efficiency method. ERF was computed as recovered waste heat divided by total electricity consumption. Surveyed sites had PUE from 1.24 to 2.27 (average 1.9). National data-centre waste-heat potential was 51.37 GWh/year, which could yield 63.12 GWh of heat with air-to-water heat pumps at COP 4.37. ERF values ranged from 0.40 to 0.69, with the highest ERF at the data centre with the lowest PUE. Distances to DH networks ranged from 3 to 2265 m (average 371.7 m), and heat-pump payback ranged from 6.44 years for the biggest site to 14.98 years for the smallest.

The model was highly sensitive to electricity prices above 260 EUR/MWh, heat-pump operation below 6570 h/year and COP below 4.75. By 2050 the national data-centre heat production potential rises to 257 GWh, of which 201 GWh is utilised.

Limits: the concentration of data centres in the capital limits national-scale waste-heat use, and a regionally decentralised data-centre network is needed for more equal use. Utilisation is highly sensitive to electricity prices and heat-pump COP, so cheaper green electricity and lower DH supply temperatures improve feasibility.

Key points

1. For the COP calculation, data-centre outlet (source) temperature was assumed to be around 18.7 °C and the required DH inlet temperature 65 °C, using the Lorenz efficiency method.
2. ERF was computed as recovered waste heat divided by total electricity consumption.
3. Surveyed sites had PUE from 1.24 to 2.27 (average 1.9); national waste-heat potential was 51.37 GWh/year, yielding 63.12 GWh of heat with air-to-water heat pumps at COP 4.37.
4. ERF values ranged from 0.40 to 0.69, with the highest ERF at the data centre with the lowest PUE.
5. Distances to DH networks ranged from 3 to 2265 m (average 371.7 m); heat-pump payback ranged from 6.44 years for the biggest site to 14.98 years for the smallest.
6. The model was highly sensitive to electricity prices above 260 EUR/MWh, heat-pump operation below 6570 h/year and COP below 4.75.
7. By 2050 national data-centre heat production potential rises to 257 GWh, of which 201 GWh is utilised.

Using it in design

• Assess waste-heat sale feasibility with ERF, heat-pump COP (4.37 for 65 °C DH inlet), distance to the DH network (3-2265 m) and payback (6.44-14.98 years) together.
• Test the sensitivity thresholds for electricity price, heat-pump running hours (6570 h/year) and COP (4.75) in the feasibility study.
• Treat lower DH supply temperatures and low PUE (which raises ERF) as positive factors in site selection.

Who should read it

Planners and energy engineers evaluating integration of data-centre waste heat into district heating.

Document contents

1. 1. Introduction
2. 2. Literature Review (2.1 Data Centers as Heat Energy Producers, 2.2 Evaluation of Heat Production)
3. 3. Methodology (3.1 Waste Heat Potential Determination)
4. 4. Results
5. 5. Discussion and Conclusions

Related standards

• EN 50600-4-6 (ERF)

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Publication details

Authors

Ieva Pakere; Kirils Goncarovs; Armands Grāvelsiņš; Marita Agate Zirne

Publisher

Energies (MDPI AG)

Year

2024

Volume

17

Issue

2

Pages

445

Document language

English

Source type

Scientific

Access

Open licence — downloadable

DOI

10.3390/en17020445

Licence

CC BY 4.0 — share with attribution

Licence evidence

www.mdpi.com

Citation