Annex 3: Emissions target baseline and proposed fleet target
Methodology
The size and composition of the public sector fleet is taken from EST’s public sector fleet decarbonisation survey for 2025. This provides the composition of the fleet by vehicle type and includes numbers of vehicles that are already zero-emission.
Average annual emissions values are applied to the fleet to estimate total annual emissions in 2025. For vehicles such as cars and vans, published emissions factors (emissions per mile) are applied to average annual mileage to estimate total emissions per vehicle. These estimates are compared with results derived from 2020 and 2022 studies of the public sector fleet, which estimate emissions using fuel consumption and mileage data reported by public sector bodies, to ensure that results are in the expected range.
For more specialist vehicle types, such as ambulances and RCVs, average annual vehicle emissions are taken from the 2020 and 2022 studies, however it should be noted that there is considerable variance in these estimates from year to year and there is limited other evidence available on how these vehicles are used.
Uncertainties
Without regular reporting on the mileage or fuel consumption of individual vehicle types across the public sector, there is uncertainty in the estimate of current emissions. This is because we do not have consistent and up to date data on the way in which vehicles are being used across all of the public sector fleet.
In addition, the level of information available for some vehicle types is very limited and the emissions estimates are sensitive to the assumptions used.
However, the approach outlined here provides a transparent draft estimate of 2025 emissions that can be used as a basis to set a target and be refined in future years as more data becomes available. As a sense check, the total level of public sector fleet emissions estimated using this approach is within 2% of the total reported by SSN in Public Bodies Climate Change Reporting - Analysis Report 2024-25.
Assumptions
Cars
- Central estimate uses average annual distance travelled by cars in the UK (11,909 km).
- Average CO2e emissions for petrol vehicles is applied to the non-ZE fleet.
- Total emissions are estimated by combining average annual CO2e emissions of an average car (2 tonnes/year) to the total non-ZE fleet in 2025.
- This is in the same region as results from the 2020 and 2022 surveys (2.1 to 2.3 tonnes of CO2e per vehicle per year)
Vans
- Average annual mileage is reported in DfT’s van survey at around 21,000 km. However, this is higher than the average van mileages reported in the 2020 and 2022 public sector fleet studies. A more conservative estimate of 16,000 km per year is assumed for vans in the public sector fleet.
- Average CO2e emissions for diesel vans <3.5t are applied to the non-ZE fleet.
- Total emissions are estimated by combining average annual emissions of an average van (4 tonnes/year) to the total non-ZE fleet in 2025.
- This is in the same region as results from the 2020 and 2022 surveys (3.6 to 3.9 tonnes of CO2e per van per year)
HGV
- Average HGV mileage and emissions factors for the general HGV fleet are available, however the use of HGVs in the public sector fleet is likely to differ to private sector vehicles used for the movement of goods and freight.
- Estimates of average emissions from public sector HGVs in the 2020 and 2022 studies are between 16.4 to 18 tonnes per vehicle per year.
- The average of these two values (17.2 tCO2e/year) is applied to the non-ZE public sector fleet in 2025.
Minibus
- The vast majority of minibuses are assumed to be derived from panel vans, and so average van emissions are assumed to be representative.
- A 2014 study found that Local-Authority owned minibuses averaged around 18,000 km per year. This is consistent with the 2020 and 2022 studies which suggest average mileage of minibuses tends to be higher than for vans.
- This suggests average annual emissions of around 4.5 tCO2e/vehicle per year.
Coach
- There are 284 coaches in the public sector fleet as at 2025, and very limited data on their use was collected through the 2020 and 2022 studies.
- Average vehicle emissions per km are taken from LowCVP Coach report 2020 web version V2.pdf
- Average annual mileage will vary significantly between vehicle use. An average of 30,000 km per year is assumed however more information on public bodies use of coaches would be required to verify this.
- This suggests an average annual emissions of around 37 tCO2e per year.
All other vehicle types (gritter; tipper; street sweepers; RCVs; ambulances; motorcycles; fire engines; tractors)
For all other vehicle types there is very limited published data on vehicle use and emissions. Therefore, average emissions per vehicle for most vehicle types estimated in the 2020 and 2022 studies are used and applied to the total non-ZE fleet in the public sector.
- For some vehicle types these estimates are based on very limited data, and so there is considerable uncertainty in estimating emissions from this segment of the fleet.
- For Refuse Collection Vehicles (RCVs), average emissions are informed by data held by EST. The overall estimate is sensitive to the value used for RCV emissions.
- For vehicles classified as ‘miscellaneous’, average car emissions are assumed. The estimates are of course sensitive to this assumption.
Results
Using the methodology above, emissions from the public sector vehicle fleet in 2025 are estimated at around 220,000 tonnes of CO2e.
This estimate is uncertain and is based on previously gathered data from the public sector, some of which is very limited. However, the estimate provides a basis from which to establish a decarbonisation target and is intended to be refined going forwards asmore data on the composition and use of the public sector fleet becomes available.
|
Vehicle Type |
Average km |
kgCO2e/km |
Average emissions (non-ZE) |
Total number of Non-ZE vehicles |
Emissions from non-ZE fleet (tCO2e) |
|
CAR |
11,909 |
0.1645 |
1.96 |
6,205 |
12,156 |
|
VAN - 3.5t and under |
16,000 |
0.2502 |
4.00 |
10,949 |
43,836 |
|
HGV |
Not Applicable |
Not Applicable |
17.20 |
1,383 |
23,788 |
|
Gritter |
Not Applicable |
Not Applicable |
13.50 |
261 |
3,524 |
|
Tipper |
Not Applicable |
Not Applicable |
9.10 |
1,636 |
14,888 |
|
Street Sweeper |
Not Applicable |
Not Applicable |
10.90 |
241 |
2,627 |
|
RCV |
Not Applicable |
Not Applicable |
47.00 |
1,236 |
58,092 |
|
Ambulance |
Not Applicable |
Not Applicable |
57.30 |
601 |
34,437 |
|
Bus Coach |
30,000 |
1.25 |
37.50 |
281 |
10,538 |
|
Bus Minibus |
18,000 |
0.2502 |
4.50 |
1,424 |
6,414 |
|
Fire Fighting Vehicle |
Not Applicable |
Not Applicable |
5.20 |
741 |
3,853 |
|
Motorbike |
Not Applicable |
Not Applicable |
1.00 |
85 |
85 |
|
Tractor |
Not Applicable |
Not Applicable |
5.75 |
616 |
3,542 |
|
Miscellaneous |
Not Applicable |
Not Applicable |
1.96 |
887 |
1,738 |
|
Grand Total |
Not Applicable |
Not Applicable |
Not Applicable |
Not Applicable |
219,516 |
Setting a target for emissions reduction
There is much variety in the public sector fleet, both in terms of the types of vehicles in the fleet and the way in which they are used. Due to the specialist nature of some parts of the public fleet, it is expected that some vehicle types will decarbonise later than those for which zero-emission solutions are already tried and tested.
However, it is recommended to have one overall emissions reduction target for the sector to work towards as a whole, rather than multiple targets for different vehicle types.
As a starting point, it is suggested that the overall decarbonisation of the public sector fleet should be at least as ambitious as the Outcome set out in the Climate Change Plan:
“Outcome 5: We will work with the energy, finance and road transport sectors and related businesses to ensure all road vehicles are zero emission by 2040”
This recognises that significant progress has already been made in the decarbonisation of cars and vans in the fleet in particular, but that it is likely to take longer for zero-emissions solutions to be adopted for heavier and specialist vehicle types.
Pathway for decarbonisation
In order to develop a pathway for public sector fleet emissions, assumptions are made about the rate at which vehicles could be decarbonised, as summarised in the table below. These figures are drawn from a March 2026 report commissioned by Transport Scotland and prepared by EST, Scottish public sector fleet electrification: Market readiness and forecasted additional costs.
|
% zero-emission |
2030 |
2035 |
2040 |
|
Car |
100% |
100% |
100% |
|
Van <3.5t |
100% |
100% |
100% |
|
HCV |
17% |
66% |
100% |
|
Bus/Coach |
50% |
100% |
100% |
|
Specialist |
5% |
35% |
100% |
|
Heavy emergency |
0% |
20% |
100% |
Future EV uptake rates are then applied to the 2025 EV uptakes rates and estimated levels of emissions to produce an emissions pathway.
Of course, there is some uncertainty in the baseline level of emissions and the actual rate of uptake may differ from that suggested below, however this provides the basis for a draft target which can be used to start the discussion with stakeholders. The results are provided in the following table. In summary, applying the assumed future EV uptake rates to the current fleet suggests:
An overall pathway of emissions reduction for the public sector fleet of:
- 34% reduction in emissions by 2030 vs 2025
- 62% reduction in emissions by 2035 vs 2025
- 100% reduction in emissions by 2040
|
Emissions (tCO2e) |
2025 |
2030 |
2035 |
2040 |
|
CAR |
12156 |
0 |
0 |
0 |
|
VAN - 3.5t and under |
43836 |
0 |
0 |
0 |
|
HGV |
23788 |
19801 |
8111 |
0 |
|
Gritter |
3524 |
3347 |
2290 |
0 |
|
Tipper |
14888 |
12455 |
5102 |
0 |
|
Street Sweeper |
2627 |
2599 |
1778 |
0 |
|
RCV |
58092 |
56036 |
38340 |
0 |
|
Ambulance |
34437 |
33151 |
22682 |
0 |
|
Bus Coach |
10538 |
5325 |
0 |
0 |
|
Bus Minibus |
6414 |
3254 |
0 |
0 |
|
Fire Fighting Vehicle |
3858 |
3853 |
3083 |
0 |
|
Motorbike |
85 |
0 |
0 |
0 |
|
Tractor |
3542 |
3387 |
2317 |
0 |
|
Miscellaneous |
1738 |
893 |
0 |
0 |
|
Total |
219,516 |
144,101 |
83,704 |
0 |
|
% change vs 2025 |
0% |
-34% |
-62% |
-100% |
| Type |
2030 |
2035 |
2040 |
|
Public sector fleet |
-34% |
-62% |
-100% |
|
CCP all road transport |
-31% |
-64% |
-86% |
Comparison with CCP pathway for road transport
Following the approach above, the pathway for emissions reduction in the public sector fleet is ultimately more ambitious than the pathway assumed for all road transport in the CCP.