I.3. ADDITIONAL ASSUMPTIONS REGARDING ELECTRIFICATION OF MOBILITY

The table below outlines the underlying assumptions used to define the various trajectories for the adoption of electric vehicles in road transport. These trajectories are determined based on different annual sales volumes and the corresponding proportions of electrification within those sales.

TABLE I-1 — ADDITIONAL INFORMATION REGARDING THE ASSUMPTIONS ON ELECTRIFICATION OF MOBILITY IN THE CENTRAL SCENARIO AND THE ASSOCIATED SENSITIVITIES

I.4. ADDITIONAL ASSUMPTIONS ON ELECTRIFICATION OF HEAT IN BUILDINGS

Additional assumptions on the quantification of the trajectories for heat pumps are presented in this section. A zoom is made on the development of heat pumps in the residential sector as it is the key sector for the development of heat pumps. Additional assumptions on the development of heat pumps in the tertiary sector can also be found in Table I-2.

The assumptions on the future evolution of the number of heat pumps in the residential sector towards 2035 depend on the number of new buildings, renovations and old heating systems being replaced, as each of these situations are considered as an opportunity for the installation of a heat pump. As such, the following assumptions are made:

• The number of new dwellings per year is assumed to remain constant until 2035, with 55k dwellings being added each year, corresponding to the previous 5-years average [STA-1] as illustrated on Figure I-4;

The resulting yearly electricity demand associated to those trajectories is presented in Figure I-3.

FIGURE I-3 — ANNUAL ELECTRICITY DEMAND FOR ROAD TRANSPORT IN THE CENTRAL SCENARIO AND THE ASSOCIATED SENSITIVITIES

• The renovation rate is assumed to increase from around 0.7% today [STA-1] to 1.2% in 2035;

• For existing oil and gas boilers it is assumed that 5% are replaced yearly which more or less reflects a lifetime of 20 years.

In terms of share of heat pumps in new sales, the following assumptions are made:

• Today, full-electric heat pumps are mostly installed in new buildings. For Flanders it is assumed that by 2025 all new buildings will be equipped i) either with a fully electric heat pump (96%) or ii) district heating (4%) due to the phase-out of new gas connections in this region [ODE-1]. For Wallonia and Brussels no strict obligations are yet in place, and it is assumed that 100% heat pump and district heating would be reached in 2035 for new buildings. As 75% of new buildings are nowadays constructed in Flanders, its policies are they key driver for electrification in this segment (see Figure I-4).

FIGURE I-5 — ASSUMED HEATING APPLIANCES INSTALLED IN NEW DWELLINGS

Key assumptions for the definition of the LOW, CENTRAL and HIGH trajectories

The underlying assumptions for the definition of the different trajectories for heat pumps are listed in Table I-2. In general, the trajectories are defined by assuming different yearly new building and renovation rates and the relative shares of heat pump installations.

TABLE I-2 — ADDITIONAL INFORMATION REGARDING THE ASSUMPTIONS ON ELECTRIFICATION OF HEAT IN THE CENTRAL SCENARIO AND THE ASSOCIATED SENSITIVITIES

• For renovations and end-of-lifetime boiler replacements, none of the regions has currently put in place a strict ban on the usage of fossil gas. Therefore, replacement of heating systems by heat pumps is assumed to increase modestly with 23% in 2030 and 35% in 2035 for renovations, and 20% in 2030 and 27% in 2035 for residual end-of-lifetime boiler replacements (see Figure I-6).

FIGURE I-6 — ASSUMED APPLIANCES INSTALLED IN THE REPLACEMENT OF OIL AND GAS BOILERS REACHING END OF LIFETIME (LEFT) AND FOR RENOVATED DWELLINGS (RIGHT)

The resulting amount of heat pumps is presented in Chapter 3, Section 3.3.4.3. The associated yearly electricity demand for the CENTRAL scenario and HIGH/LOW sensitivities is presented in Figure I-7.