Charging Infrastructure

SPR vehicles are powered by battery systems. These can be permanently installed or swappable. Our preference is for permanent  batteries as explained below.

Advantages of Battery Systems over external power systems

  • No capital needed for installation of power lines and associated sub stations. This is an important aspect for HS2 given the projected cost of construction. (Battery Banks have similar needs but they can be located more conveniently). We suggest the saved amount in this area be directed to constructing a overhead canopy as described in Roadway page

  • Batteries have a ‘round trip’ efficiency of 90%-95% comparable or better than energy losses over length of power line for either AC or DC systems. Obviously the figure for power lines vary but realistically for a 120 mile line (as for HS2) at least 10% loss should be assumed..(even more when taking into account the inefficiencies of the pantograph connection and the continuous energising required. Batteries on the other hand use most of their energy in useful work. Transmission is supply led not demand led.

  • No rectification or transformer systems needed on board Shuttles to convert AC to DC power suitable for batteries and motors.

  • Far lower maintenance costs for battery systems. Transport and battery changing systems are mechanically simple and autonomous requiring less human interaction.

  • No electric power is required for vehicles in stations increasing safety and reducing construction and OEM costs.

  • No drag penalty for contact wheels or shoes, or aerodynamic losses from pantographs

  • No weather issues such as ice formation, debris and winds ( to be fair the proposed canopy element of the SPR system will provide protection for both types of system)

  • Allows a variety of formats to be adopted (Robocars, Single Shuttles, entrained Shuttles).

Battery Cells and Packs

Permanent Battery Systems

Whilst there may be many ways to package battery systems we conceive of the system as follows:

  • Battery cells (2170 or 4680 cells) are installed in battery packs (1.2m x 1.8m), with a capacity of 90-100kWh or more

  • These packs are installed in groups of four beneath each vehicle section.

  • Physical contact or induction charging can be used.

  • When charging the vehicles would simply align with static charging points in the roadway and using their air suspension lower themselves onto these points

  • A full charge should take one hour.

  • Vehicles can be charged at times of low demand (e.g at night) and queued for peak times. This will allow less draw on the power grid at peak times. This could not be avoided by HS2 trains in their projected density of 36 trains an hour (or even 10 trains for Birmingham and Manchester only,

Battery cooling systems 

Permanent batteries with liquid cooling in the Shuttles will have the advantage of both better aerodynamic performance and higher energy density as cells can be more tightly packed.

Charging Structure in the Roadway

  • No moving parts are required for charging structures All movement is undertaken by the vehicle. This reduces maintenence and construction requirements

  • Soil removal and water replenishment would operate in a similar way and could be located either within the charging areas or separately (given that it can complete its task within seconds)

  • Cleaning services can be undertaken whilst vehicles are being charged. We have allowed for safe access in our designs for charging areas.

  • We have envisioned either a dedicated ‘warehouse’ charging area to be located within a couple of kilometres of major stations or alternatively charging can be undertaken alongside or above the main trackway.

We calculate that the largest 64 seat Shuttle, which would have at least 1.5 MWh of Energy. This is enough energy to allow the shuttle to undertake a 155mph return trip between Birmingham and London without recharging.