# Analysis of Instantaneous Energy Consumption and Recuperation Based on Measurements from SORT Runs
## 2 Materials and Methods
### Problem Formulation
Energy measurements are taken at crucial places within the bus's power distribution network, specifically at the PowerBox and main high voltage (HV) connections illustrated in the diagram. The creation of this link allows for the recording of time-series data, which includes real-time monitoring of energy consumption and recuperation. In order to evaluate electric bus performance in a simulated real-world environment, the SORT methodology uses these measurements. The device for measuring electricity consumption is connected in the places shown in Figures 1 and 2. Figure 1: Schematic diagram of the current circuit. The Current Clamp connection point is marked with a red circle. The markings shown in the diagram with Polish names are as follows: Bialy represents ’White’, Pomaráczowy represents ’Orange’, Zótty represents ’Yellow’, and Zielony represents ’Green’. The standardised on-road test (SORT), developed by the International Association of Public Transport (UITP) to assess buses' fuel or energy consumption under operating conditions, consists of three standardised scenarios: SORT 1, for extreme urban traffic with frequent stops; SORT 2, for mixed driving conditions with moderate stops; and SORT 3, for suburban roads with minimal stops. Their main purpose is to enable comparison of the energy efficiency of different vehicles under specific conditions. This allows contracting entities, e.g., public transport operators, to make decisions based on data on actual energy consumption during use. SORTs are divided into three cycles reflecting different bus operating scenarios:  
* SORT 1 simulates intensive urban traffic, where the vehicle moves at a low average speed of around 12 km/h, stops frequently (6-8 times per kilomet), and the stop time is up to 35% of the total driving time. * SORT 2 reproduces milder urban conditions, with fewer stops (3-5 per kilomet), an average 18 km/h speed, and a stop share of around 20%. * SORT 3, on the other hand, is designed for suburban routes, where the average speed is around 25 km/h, the number of stops is reduced to 1-2 per kilomet, and the stop time is only 10%. The test procedure requires the bus to be fully loaded per the permissible total weight, including passengers and cargo. Tests are carried out on a fixed section of the road  
Figure 2: Overview schematic of the Voltage measurement point. The connection points of the clamps are marked with a red circle. The markings in Polish are as follows: Bialy represents ‘White’, Pomaráczowy represents ‘Orange’, Brazowy represents ‘Brown’, and Zielony represents ‘Green’. corresponding to the given cycle's specifics. The results are measured multiple times to obtain accurate data. Maintaining constant weather conditions, such as temperature or lack of wind, is also important, and the vehicle must be in perfect technical condition. The SORT results measure energy or fuel consumption expressed in kWh/km or litres per 100 km. These results are crucial for comparing different buses, regardless of their type of drive: combustion, hybrid, electric or hydrogen. By standardizing the procedure, the UITP ensures consistency of results, which is particularly important in public tenders and planning strategies for implementing zero-emission vehicles. The test is useful for assessing electric bus efficiency and confirming battery performance claims, as it records precise data on energy consumption and recuperation in each scenario. Operators of fleets, producers, and decision-makers must have these metrics, they supply the essential data when optimising route planning, enhancing energy management methods, and decreasing operational costs. To ensure these measurements are reliable, it is crucial to use the current clamp connection locations in Figure 1. This will help achieve the larger objective of making electric public transport systems more efficient and sustainable. During an SORT, the voltage measurement sites of an electric bus can be seen in Figure 2, which is a representation of the test.