electric cars and buses

Dr Robert Carpenter, MD of Inside2Outside Ltd, provides a detailed insight into electric cars and buses which he argues will be the principal mode of transport soon

Smart Hubs are localised hubs integrating solar car parks (a parking facility made up of solar car ports), electric vehicle (EV) charging, battery energy storage, Vehicle to Grid (V2G) energy management together with local power generation and usage, managed by a smart energy management system which enables the best use of power at the local level.

Electric cars and buses are going to be the principal transport mode in just a few years. However, we know that the current electricity grid system will only be able to cope if smart charging and grid management are adopted across the network. “The investment in infrastructure to support increasing numbers of electric vehicles indirectly benefits all energy consumers through lower prices and lower carbon generation intensity, as smart charging of EVs can support increased renewable generation.” (1)

Car parks and transport hubs that incorporate solar car parks (solar panels installed on structures to harvest clean green power from the empty space above cars parked in car parks), energy storage systems and smart energy management enable more EV charging with less strain on the grid. This will mean that costly and disruptive grid reinforcement can be avoided, saving potentially significant sums of money for the infrastructure developers and benefiting society as a whole.

Clean energy hubs based around solar car parks also represent very visible green innovations for local authorities, retail centres, public car park owners, airports and train operators, while presenting a new source of revenue to the site owner, a greater level of service to the car park user as well as significant contributions to grid management and stability. “Flexible and fast charging is essential for facilitating the transition to EVs in the most cost-effective way, by enabling all consumers (including those who do not own an EV) to benefit from a more optimised energy system and avoiding reinforcement costs.” (2)

Smart Hubs is becoming the generic term for intelligent EV charging and localised power management, working towards zero emissions (3). Smart Hubs integrate local renewable energy generation, solar car parks, battery storage and energy management, and can potentially include other energy technologies such as hydrogen generation, storage and delivery into hydrogen-powered vehicles. The electrification of road transport will have significant impacts on the energy system, potentially increasing today’s electricity consumption by about 30% by 2045. This represents a significant and potentially costly challenge for the power sector, and the costs can be greatly reduced through the adoption of new business models for smart charging and local energy management and providing accessible choices for individuals for how they choose to charge their vehicles. (4)

However, if Smart Hubs are going to be successful in achieving sufficient adoption of solar car parks and local energy management to deliver a significant impact on the grid and EV charging, it is important to consider the incentives for all parties involved in the Smart Hubs ownership and use.

Why Smart Hubs?

Site owner

The solar car park owner is a diverse demographic, with equally diverse aims for their car park use. The site owners ‘raison d’etre’ may range from simply obtaining the most revenue from their solar car park site, through providing a service to the community or meeting corporate decarbonisation goals, to attracting spenders to their site.

For example, a long stay airport car park owner, whose users will be leaving their cars in their care for predictable lengths of time, may be able to leverage the existing storage capacity of those parked vehicles – for example – 15,000 vehicles, with an average battery capacity of 100kWh (subject to the manufactures warranty), would provide over 1 GWh of battery storage. This can be used to maximise the cost and carbon benefits of the generated power from the solar car park, providing a significant saving for an airport both in power costs, but probably more significantly, in CO2 production. This storage capability could also be used to provide services to the electricity grid, which includes paid services to support the stability and efficiency of the electricity system.

This is a very different car park user demographic to a local authority park and ride car park owner. Here, vehicles may be on site for a working day, but also may be parked for a shorter and – more importantly – unpredictable period of time. The benefits for the site owner of a Smart Hub solar car park solution still include offering low carbon EV charging to these customers but may also include the significant additional benefit of providing off-street EV charging for local residents who do not have access to charging facilities at home (for example, flats or houses with no off-street parking). The site may also provide facilities for Rapid EV charging for ‘en route’ charging, providing a vital service for taxis, buses, delivery vehicles or individuals taking longer journeys, and offering an additional revenue stream to the site owner. Rapid charging infrastructure has the potential to put a particularly significant strain on the electricity network, potentially incurring prohibitive charges to establish the infrastructure. In these cases, a Smart Hub solution may be particularly beneficial.

These compare to a retail centre car park owner, whose principal aim of owning the solar car park would be to provide a service – or incentive – to potential users of the retail centre while being seen to be green. The solar car park itself can provide a highly visual and aesthetic display of the clean credentials of the site, as well as providing shaded parking locations that may be desirable on sunny days. Battery energy storage can be sized to simply maximise the use of the generated energy for charging, to support onsite electricity loads with lower-cost electricity and manage usage to within connection agreements, or to provide electricity grid services providing additional income streams.

Of course, a site owner who considers the rental of each car parking space economically important either as part of their income forecasting or towards that of the site itself (retail or leisure sites), will be particularly keen to ensure that solar car parks do not reduce the number of parking bays within the car park. For this reason, the solar car parks system developed by Inside2Outside Ltd has been specifically designed not to take-up any car parking space within the car park (5).

As illustrated by these examples, and many more, Smart Hubs enable flexibility for all owner types to meet their aims by adjusting the parameters within the energy management system within the Smart Hub to prioritise energy flows allowing their preferred outcomes.

Why Smart Hubs? The site user

Of course, the site user is equally diverse, but to use the same examples as above:

A long stay car park user may principally be concerned with cost-effective pricing for their secure parking and having a full battery on their return. Incentivising the car park user to choose your car park by reduced fees, or even paid for parking in return for the (safe) use of their vehicle battery while parking could well be a ‘win/win’ for those involved. In addition to this, customers are becoming increasingly carbon-conscious, and the combination of green energy and the support of the wider electricity network can be a notable selling point.

A park and ride user who has access to off-road EV charging at home, may be interested in EV charging at a park and ride site – as long as the price is right, allowing them to replace the power used to reach the car park site while accessing the destination of the park and ride. This user would possibly be as interested in park and ride ease of use, costs and reliability.

This compares to a park and ride user who has no access at home to off-road car charging, whose principal reason to visit the park and ride site, maybe to get their vehicles charged while using the ride provided to get to work or to access the local facilities. For this user, the facility is a vitally important enabler to the viability of owning an EV in the first place.

The flexibility within the solar car park and energy management system contained within the Smart Hub allows the opportunity for the socially conscious site owner to prioritise, or to incentivise this user type to access their park and ride site by providing reduced price – or even subsidised – EV charging, either subsidised through fast and rapid charging facilities offered on the same site or as part of their local service offering.

Taxis, delivery drivers, and people on longer journeys will require charging at strategic locations and may well pay a premium for the ability to charge quickly and conveniently.

A retail centre car park user, on the other hand, may be incentivised to use a particular retail centre with improved car park facilities – whether from protection from sun, rain, wind, or snow provided by covered solar car parks or from subsidised EV charging, particularly if they are carbon-conscious customers who will be attracted by the idea of green and smart energy systems.


When planning and financing solar car parks and Smart Hubs, consideration should be made to the future uptake of the facilities. Maximising the future benefits of Smart Hubs, however, requires sound technical, operational and commercial considerations. The decision-making process is rendered particularly difficult by the uncertainty in EV ownership and use, driver behaviour and preference, and the future of the electricity and service markets – all this is in addition to the uncertainty/unpredictability of renewable power generation.

In other words, as well as predicting when the sun will shine, or the wind will blow, or the price of electricity into the future, a Smart Hubs planner should also take into consideration major questions such as- ‘how quickly the take-up of EV will increase?’, together with more intransigent insights such as how long the EV user will remain at the Smart Hub, how much charge the user would like to gain from their visit and how quickly the vehicle can be charged. On top of these, for the V2G aspect of a Smart Hub, how quickly will the concept of V2G (or vehicle to anything/all) be taken up by the EV user and manufacturer?

Modelling of these systems forms a major part of the decision-making process. Models using artificial intelligence and simulation approaches should be considered.


One particularly flexible aspect of Smart Hubs is the opportunity to future proof your solar car park, allowing the owner to flexibly increase the number and type of EV charging points available, as take-up of EV increases, without the need for significant disruption of the car park. This allows the car park owner/operator to ‘Be EV Ready’ with their planning.

As the Smart Hub energy management system is continually optimising for changing circumstances, it can adapt to changing system infrastructure (for example, if more storage or solar generation is added), changing customer behaviour (for example, of vehicles are parking for longer, or requiring more rapid charging), or system information (for example, if the price of electricity or the electricity grid services market changes). This allows the business model of the Smart Hub to adapt over time to provide maximum benefit and suit the requirements of the site owners and users.

Dr Alistair Martin, Chief Strategy Officer at Flexitricity Ltd says: “I believe that smart vehicle charging will be the difference between the success and failure in reaching our electric vehicle ambitions. Having the ability to recharge in a short time using grid friendly infrastructure will have a huge impact on the electric vehicle market – it is really a question about how quickly we can deliver this capability.” (6)


National Grid ‘Future Energy Scenarios in five minutes 2019’ – http://fes.nationalgrid.com/media/1410/fes-in-5-2019.pdf

Ofgems’ Future Insights series ‘Implications of the transition to Electric Vehicles’ – https://www.ofgem.gov.uk/system/files/docs/2018/07/ofg1086_future_insights_series_5_document_master_v5.pdf


‘Energising Our Electric Vehicle Transition’ – Electric Vehicle Taskforce, Office for Low Emission Vehicles, HMG.




Please note: This is a commercial profile

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