Ardor
Calculation Model & Sources

Methodology & Documentation

How Ardor calculates waste heat , which data sources we use, and which regulations our reports are based on. All technical terms are marked with a dashed underline — hover for definitions.

Hover Glossary
Das deutsche Energieeffizienzgesetz. Verpflichtet Rechenzentren ab 300 kW IT-Nennleistung zur jährlichen Dokumentation ihres Abwärmepotenzials., Bundesamt für Wirtschaft und Ausfuhrkontrolle. Die Bundesbehörde, bei der Ihr jährlicher Abwärmebericht eingereicht werden muss., Bundesstelle für Energieeffizienz. Die Berichterstattungsplattform des BAFA für Energieeffizienz-Meldungen., Power Usage Effectiveness. Verhältnis Gesamtenergieverbrauch zu IT-Energieverbrauch. PUE 1,0 = perfekt effizient. Typisch: 1,3–1,6., IT nameplate capacity, District heating network, Proximity analysis, Feasibility, Waste heat reuse quota, Heat pump, Heat sink, EnMS / EMS, Primary energy factor.

Heat Output Calculation Model v1.0

The calculation follows the thermodynamic principle that virtually all electrical energy in a data centre is converted to heat. The recoverable fraction depends on the cooling type.

Waste heat (MWh/a) = IT load (MW) × PUE × 8,760 h × ηcapture

Default Assumptions by Cooling Type

Cooling TypeTemperatureηcaptureApplication
Liquid cooling (direct-to-chip)60–80°C70–90%District heating, process heat
Hybrid cooling (air + liquid)40–60°C50–70%Low-temperature district heating
Air cooling25–40°C30–50%Greenhouses, building heating with heat pump

Worked Example: 10 MW, Air Cooling, PUE 1.4

Total power = 10 MW × 1.4 = 14 MW
Annual energy = 14 MW × 8,760 h = 122,640 MWh/a
Recoverable = 122,640 × 0.50 = 61,320 MWh/a
≈ 3,066 German households (20 MWh/household)

Data Sources

Facility data

Data Center Map

Public database of European data centres with addresses and operators.

datacentermap.com
Geodata

OpenStreetMap

Industrial zones, commercial areas, facilities (hospitals, universities).

openstreetmap.org
Network data

AGFW District Heating Map

Routing and coverage of German district heating networks. Energy efficiency association for heating.

agfw.de
Industry benchmarks

Bitkom e.V.

Annual studies on PUE values and efficiency metrics of German data centres.

bitkom.org
Industry benchmarks

Uptime Institute

Global PUE averages and efficiency trends.

uptimeinstitute.com
Regulation

BAFA & BfEE

Official guidance on EnEfG reporting obligations and the waste heat platform.

bafa.de

Regulatory Foundations

§§ 11–13 EnEfG

Data centre-specific obligations: PUE targets, waste heat reuse quotas, annual filing to the Data Centre Register by 31 March.

§ 17 EnEfG

General waste heat reporting obligation. Enterprises consuming above 2.5 GWh final energy per year submit waste heat data to the BfEE platform by 31 March.

Regulatory Glossary

Key terms from the EnEfG, BAFA regulation, and waste heat utilisation in plain language.

EnEfG
Energy Efficiency Act
The German Energy Efficiency Act. Requires data centres from 500 kW IT nameplate capacity to document their waste heat potential annually.
BAFA
Federal Office for Economic Affairs and Export Control
The federal authority to which your annual waste heat report must be submitted.
BfEE
Federal Energy Efficiency Agency
BAFA's reporting platform for energy efficiency filings.
Waste heat utilisation
Industrial waste heat recovery
Use of waste heat from data centre operations for external purposes: district heating, greenhouses, industrial processes.
Waste heat reuse quota
Mandatory share per § 12 EnEfG
Legally mandated minimum share of waste heat to be utilised. 10% (2026), 15% (2027), 20% (2028) where technically and economically feasible.
PUE
Power Usage Effectiveness
Ratio of total energy consumption to IT energy consumption. PUE 1.0 = perfectly efficient. Typical: 1.3–1.6. EnEfG target for new builds: ≤ 1.2.
IT nameplate capacity
Installed IT Power Demand
Installed IT power capacity in kW or MW. Determines EnEfG obligation (threshold: 500 kW for § 17, 300 kW for § 13).
District heating network
District Heating Network
System of insulated pipes for heat distribution from a central source. Most common off-taker for data centre waste heat.
Feasibility
Feasibility
Technical and economic assessment of waste heat utilisation. Categories: FEASIBLE / MARGINAL / NOT FEASIBLE.
Proximity analysis
Proximity Analysis
Assessment of potential heat off-takers in the vicinity of a data centre. Distance, temperature requirements, offtake volume.
EnMS / EMS
Energy / Environmental Management System
Mandatory from July 2025. Accepted standards: ISO 50001, ISO 14001, EMAS.
Primary energy factor
Primary Energy Factor
Factor describing the total energy input required to produce one unit of energy. Relevant for efficiency assessment.
Heat sink
Heat Sink / Off-taker
Building, business, or network that can use waste heat. Examples: district heating networks, greenhouses, hospitals, industrial plants.
Heat pump
Heat Pump
Raises low-temperature waste heat (25–40°C) to usable temperatures (55–70°C). Typical COP 3–4.
Liability Notice

Reports generated by Ardor are produced using automated methods. The operator is responsible for the accuracy of the data and for regulatory-compliant submission. Ardor assumes no liability for the use of reports vis-a-vis authorities. All methods, data sources, and assumptions are documented and verifiable in every report.