MW and MWh: power is not energy
A watt measures instantaneous power. A watt-hour measures energy over time. A 1 MW installation running at full power for one hour produces 1 MWh.
kWh, MWh, GWh and TWh: changing scale
Prefixes only change the order of magnitude. 1 MWh = 1,000 kWh; 1 GWh = 1,000 MWh; 1 TWh = 1,000 GWh. EnergyBoard mainly uses GWh for annual electricity generation.
TJ and PJ: large units for households and transport
The joule is another energy unit. Eurostat publishes many balances in TJ. EnergyBoard uses TJ for household energy and converts very large transport volumes to PJ for readability.
toe, kgoe and Mtoe: comparing different forms of energy
Oil equivalent converts different forms of energy into a common unit. By Eurostat convention, 1 toe = 41.868 GJ, about 11.63 MWh. Therefore 1 Mtoe is about 11.63 TWh.
€/kWh, tax levels and €/kgoe: three different readings
€/kWh measures an energy price. Eurostat prices must also be read with their tax scope: excluding taxes, taxes excluding VAT, or all taxes included. €/kgoe is different: it measures energy productivity.
HDD and CDD are not energy units
Heating degree days (HDD) and cooling degree days (CDD) are weather-based indices describing theoretical building heating and cooling needs. They cannot be directly converted into kWh, TJ or PJ.
% and percentage points
A move from 20% to 25% is +5 percentage points but a 25% relative increase. EnergyBoard uses “pt” for direct differences between shares.
NR, PC and survey percentages: read the measurement type
Housing pages combine dwelling counts with survey percentages referring to people. In Eurostat data, NR means number and PC means percentage. A housing-stock total must therefore not be read as a rate.
Always read the reference year
Housing datasets do not share one reference year: Census 2021 describes housing-stock structure, 2023 covers heating systems, and 2025 covers several housing-condition and energy-improvement indicators. EnergyBoard displays the year next to each value.
Quick reference table
| Symbole | Measures | EnergyBoard |
|---|---|---|
| MW | Power | Solar, wind and hydro capacity |
| GWh / TWh | Energy | Annual electricity generation |
| TJ | Energy | Households and detailed energy balances |
| PJ | Energy | Large transport volumes |
| Mtoe | Normalised energy | Final energy consumption |
| €/kWh | Price | Electricity and gas |
| €/kgoe | Productivity | Economic value per unit of energy |
| NR | Number | Census dwelling counts |
| PC | Percentage | Survey indicators referring to people |
| HDD / CDD | Climate index | Theoretical heating / cooling needs |
| % / pt | Share / difference | Renewables, dependency, rankings |
Concrete EnergyBoard examples
Installed power, not electricity generated over a year.
A quantity of electricity generated during one year.
A very large energy quantity; 1 PJ = 1,000 TJ.
A climate index for heating needs, not 2,800 kWh.
A price: check whether it excludes taxes, excludes VAT or includes all taxes.
A Census 2021 count in NR, not a percentage.
A 2025 survey percentage of people unable to keep their home adequately warm.